JP2003112354A - Method for manufacturing foamed resin extrusion molding with coating sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a foamed resin extrusion molding with a coating sheet which can be good and efficiently manufactured without bringing about resin clogging in a cooling sizing mold, a molding fault such as a breakage, a deformation or the like at the time of drawing at a molding using a softer thermoplastic resin than prior art, a molding having a high expansion ratio, a molding or the like of a complicated sectional shape. SOLUTION: The method for manufacturing the foamed resin extrusion molding with the coating sheet comprises the steps of introducing the foamed resin material 12 extruded from an extrusion mold 11 in a heated plasticized state into the cooling sizing mold 14, cooling to solidify the resin material, and simultaneously coating a coating sheet 13 on at least part of the surface of the material 12 in the mold 14. Particularly, the foamed extrusion molding of the material 12 is preferably performed by an inward foaming process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foamed resin extruded product with a covering sheet, which is obtained by coating at least a part of the surface of a foamed resin extruded product with a covering sheet, and more particularly to a floor material. The present invention relates to a method for producing a foamed resin extruded product with a covering sheet, which is suitable for various applications such as building materials such as wall materials, ceiling materials and fittings, vehicle interior materials, parts of electric machinery and equipment, casings and the like.

[0002]

2. Description of the Related Art A foamed resin molded product formed by molding a thermoplastic resin, the inside of which has a cellular shape by foaming, into a predetermined shape is lightweight, has high heat insulating properties, is inexpensive per volume, and can be processed. It has been widely used in various applications already mentioned above, because of its various advantages such as its ease of use. Although various methods for producing these foamed resin molded articles are known, among them, as a production method capable of continuously and efficiently producing a long-sized foamed resin molded article having a constant cross-sectional shape, thermoplastic resin is used. A foamed resin material obtained by adding a foaming agent is melt-kneaded by heating and extruded from an extrusion die by an extruder, and is introduced into a cooling sizing die while foaming it, and the internal shape of the cooling sizing die is exactly the same. The foaming extrusion molding method in which the material is cooled and solidified while being shaped into a cross-sectional shape and outer dimensions is most widely used.

However, in the foaming extrusion molding method described above, the foaming resin material introduced into the cooling sizing die is pressed against the inner wall surface of the cooling sizing die by the foaming pressure of itself, so that the foaming resin material and the cooling material are cooled. In many cases, slippage between the sizing die and the inner wall surface of the sizing die becomes poor, which causes inconvenience in molding. For example, the foamed resin material in a heat-plasticized state that passes through the inside of the cooling sizing die while being foamed by being extruded from the extrusion die, cannot overcome the frictional force between the inner wall surface of the cooling sizing die, It is clogged inside the cooling sizing die and cannot be taken (cannot be continuously demolded from the cooling sizing die), or is pulled from the cooling sizing die with internal stress remaining strongly due to the influence of frictional force. , The internal stress is released after the take-up, and deformation such as warping, bending, and twisting occurs, or the foamed resin material stretches or breaks when the foamed resin material clogged inside the cooling sizing die is forcibly pulled out. In many cases, it is difficult to manufacture a good foamed resin extruded product due to various molding failure accidents. Such a problem is, when trying to produce a foamed resin extruded product with a high expansion ratio, or as a thermoplastic resin which is the main component of the foamed resin material, a resin having a low elastic modulus or a resin having a slow crystallization rate, Alternatively, when a resin having high metal adhesion is used, it tends to occur particularly remarkably. Therefore, in the case of producing a foamed resin molded body by the foamed extrusion molding method described above, the foaming ratio of the foamable resin extruded body that can be manufactured, the elastic modulus of the thermoplastic resin that can be used, the crystallization rate, The reality is that there are major restrictions in terms of metal adhesion.

Further, if the cross-sectional shape is a simple shape such as a circle or a rectangle, there will be no serious problem, but it may be a thin plate shape that is thinner than the width, or a shape having complicated irregularities on the surface. Then, even if the expansion ratio is a normal degree, in comparison with the cross-sectional area of the foamed resin material, the contact area with the inner surface of the cooling sizing die is relatively increased, as a result, the influence of the frictional force is strong, Various types of molding failure accidents as described above may occur. Under these circumstances, the expansion ratio of the foamed resin extruded product that can be manufactured by the foamed extrusion molding method while maintaining good shape and dimensional accuracy, the properties of the thermoplastic resin used, the cross-sectional shape of the molded product, etc. There are various restrictions,
Weight reduction, high heat insulation, price reduction, which have been increasing in recent years,
The current situation is that we have not been able to fully meet market demands for higher functionality and expanded applications.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art. The problem is to use a thermoplastic resin softer than before. Molded products and molded products with high expansion ratio,
It is an object of the present invention to provide a method for producing a foamed resin molded article, which enables good and efficient production of a molded article or the like having a complicated cross-sectional shape without causing defective molding.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a method for producing a foamed resin extruded product with a covering sheet, which comprises coating a covering sheet on at least a part of the surface of a foamed resin extruded product, which comprises heat plasticization. In the state, the foamed resin material extruded from the extrusion mold is introduced into the cooling sizing mold to be cooled and solidified, and at the same time, inside the cooling sizing mold, a coating sheet is formed on at least a part of the surface of the foamed resin material. A method for producing a foamed resin extruded product with a covering sheet, which comprises coating.

In particular, the present invention relates to a method for producing a foamed resin extruded product with a covering sheet, characterized in that the foamed resin material is extruded and molded by a selka method.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic process drawing for explaining an example of a method for producing a foamed resin extruded product with a covering sheet according to the present invention. According to this step, a thermoplastic resin to which a foaming agent, a filler, various additives, and the like are appropriately added is kneaded while being plasticized by heating in the extruder 10, and thus the foamed resin material in a heat-plasticized state is obtained. 12 is extruded from an extrusion die 11 attached to the tip of the extruder 10 to cool the sizing die 1
Introduced in 4. The cooling sizing mold 14 (also referred to as a calibrator mold, a guide mold, etc.) has an inner wall surface whose cross-sectional shape is precisely manufactured according to the cross-sectional shape of a molded product to be manufactured, and the inner wall surface is foamed. Resin material 12
However, by cooling and solidifying while being pressed by its own foaming pressure, a foamed resin extruded product having a cross-sectional shape as designed, which accurately copies the cross-sectional shape of the inner wall surface of the cooling sizing die 14, is stable. Is manufactured.

Here, in the manufacturing method of the present invention, when the foamed resin material 12 is introduced into the cooling sizing die 14, at least a part of the surface of the foamed resin material 12 is a solid sheet-like body. The cover sheet 13 is inserted between the cover sheet 13 and the inner wall surface of the cooling sizing die 14. After that, the covering sheet 13 is sent together with the foamed resin material 12 in the flow direction (the direction of the white arrow in the figure) in a state of covering at least a part of the surface of the foamed resin material 12. Then, in the cooling sizing die 14, the foamed resin material 12 that has been cooled and solidified to the extent that it is not deformed by its own weight is taken (demolded) from the cooling sizing die 14 by the action force of the take-off machine 16. After being sufficiently cooled by passing through a cooling tank 15 such as a water tank, it is sent to a cutting table 17 and cut into a predetermined size by a cutting blade 18. In this way, the foamed resin extruded product 19 with a cover sheet, which is the target product, is obtained.

There are roughly two types of known foaming extrusion molding methods for thermoplastic resins. On the other hand, as shown in FIG. 2, an extrusion die 11 having an inner wall surface dimension smaller than that of a molded body to be produced is used, and a foamed resin material in a heat plasticized state extruded from the extrusion die 11 is used. 12 is an extruder 10
By using the phenomenon in which foaming is suppressed by the high pressure inside, it is reduced to atmospheric pressure and suddenly foamed, and foamed to a size close to the external dimensions of the molded product to be manufactured. From this, it is a method of introducing into the cooling sizing die 14. This method is called the normal method because it has been the most general method in the past, and the foamed resin material 12
It is also called a free method (free process, free forming process) because it foams in a free state without being bound by a mold under atmospheric pressure.

The other has, as shown in FIG. 3, an inner wall surface dimension substantially the same as the dimension of the molded body to be manufactured, and
A foaming resin material 12 is extruded in a hollow state by using an extrusion die 11 in which a torpedo 20 (also referred to as a mandrel, a core, etc.) is mounted, and a cooling sizing die in a state where the foaming hardly progresses. This is a method of introducing into the mold 14 and foaming mainly inside the cavity toward the inside. This method was developed by Eugene Coolman of France and was widely introduced under the name of the SELCA process (SELCA process). It is also called the inward forming process because of the characteristic that the resin foaming progresses toward the inside. Has been done.

In the method for producing a foamed resin molded article with a covering sheet according to the present invention, as the foaming extrusion molding method of the foamed resin material 12, either of the above-mentioned ordinary method and selka method can be adopted, which is a desired product. It may be appropriately selected depending on the use of the molded product. In the case of the selka method, the foamed resin material 12 extruded from the extrusion die 11 is immediately introduced into the cooling sizing die 14 and its outer surface is rapidly cooled, so that as shown in FIG. The inside is filled with the cavity due to foaming toward the inside to form a highly foamed layer 22, while the surface layers are characterized by skin layers 21 and 23 remaining in an unfoamed or low foamed state. It is suitable for applications that require hardness, water resistance, and rigidity of the molded product as a whole. On the other hand, the expansion ratio of the molded body as a whole cannot be increased due to the skin layers 21 and 23. Therefore, it is suitable for applications requiring a highly elastic and lightweight high-foam material, or applications requiring surface flexibility. It can be said that the usual method is suitable because the skin layers 21 and 23 are not formed and high foaming is possible.

However, in the case where the cover sheet 13 is used as it is as a surface protective layer after molding, the adhesiveness between the cover sheet 13 and the foam layer (foam resin material 12) is important. From this point of view, since the bonding surface of the foam layer with the cover sheet 13 has a high density, it is easy to form a strong bond, and when coating in the cooling sizing die 14, the void tends to face inside. It can be said that the selka method is superior because it is easy to form a strong bond due to the pressure of pressing the surface layer (skin layer 21) of the foam layer against the cover sheet as a reaction of all foaming. In the case of the selka method, the unfoamed or low-foamed skin layer 2
Due to the rigidity of 1, 23, the cooling sizing mold 1
4 has a strong resistance to a frictional force with the inner wall surface, and is for the purpose of preventing the clogging of the resin in the cooling sizing die 14 and the deformation / breakage at the time of taking the resin from the cooling sizing die 14, which is the object of the present invention. Can be said to be a more effective method.

In the selka method, even if the extrusion die and the cooling die have almost the same size, the skin layers 21 and 23 are not formed on a part of the outer surface of the molded body, so that the extrusion die 11 is formed at that part. Inner wall dimension cooling sizing mold 14
It can be designed smaller than that. However, in the case where the covering sheet 13 is also coated on this portion, in order to ensure good adhesion between the covering sheet 13 and the foamed resin material 12, it is sufficient to foam the foamed resin material 12 on the surface of the covering sheet 13. Since it is important that pressure is imposed,
In consideration of that, the extrusion die 11 and the cooling sizing die 14
It is necessary to design the difference in the inner wall surface dimension between and.

The insertion of the cover sheet 13 is performed between the extrusion die 11 and the cooling sizing die 14, but if the gap between the two is too large, it may be introduced into the cooling sizing die 14. Since the solidification of the foamed resin material 12 due to natural cooling progresses, and the adhesive force on the surface and the foaming pressure decrease, sufficient adhesion with the cover sheet 13 may not be obtained, so the extrusion mold 11 And cooling sizing mold 14
The distance between and must be as small as possible. However, when it is impossible or difficult due to the shape of the molded body or the like (particularly in the case of the ordinary method), before inserting the covering sheet 13,
Appropriate adhesive is applied to the adhesive surface of the covering sheet 13 with the foamed resin material 12, or the adhesive surface of the covering sheet 13 and / or the foamed resin material 12 is subjected to surface activation treatment such as corona discharge treatment or ozone treatment. May be dealt with.

The covering sheet 13 may cover the entire surface of the foamed resin material 12 including the upper surface, the lower surface, the side surfaces, or only a part of the surface such as only the upper surface or only the upper surface and both side surfaces. You may coat. When covering a plurality of surfaces of the foamed resin material 12, a plurality of cover sheets 13 may be covered on each side, or one cover sheet 13 is wound around the circumference of the foamed resin material 12. However, it may be coated over a plurality of surfaces. However, if the ratio of the area covered by the covering sheet 13 to the total surface area of the foamed resin material 12 is too low, the object of the present invention may not be sufficiently achieved. Therefore, the ratio of the covered area is generally one third or more. It is desirable to do. In addition, when the molded article which is the object includes a complicated shaped portion such as a concave groove portion or a ridge portion on the outer surface thereof, the covering sheet 13 includes all or at least a part of the complicated shaped portion in the covering range. Coating is more advantageous for achieving the object of the present invention.

The cover sheet 13 is firmly adhered to the foamed layer made of the foamed resin material 12 and is often used as a surface protective layer or a decorative layer, but the present invention is not limited thereto. However, for example, it does not peel off spontaneously during foaming extrusion molding, but after molding, that is, after the completion of the foamed extrusion molded body with a covering sheet 19, the adhesive strength is such that it can be peeled off easily. It can also be used as a protective film or a squeezing sheet (embossing film). Further, in order to prevent the surface of the covering sheet 13 or the foamed resin material 12 from being scratched due to friction with the cooling sizing die, the covering sheet 13 for adhering to the foamed resin material 12 is additionally provided on the outside thereof. It is also possible to insert a film or the like that can be easily peeled from them later as the second cover sheet.

In the present invention, the kind of the thermoplastic resin used as the main component of the foamed resin material 12 is not particularly limited, and any thermoplastic resin may be selected depending on the intended use of the foamed resin molded product. Good. Specifically, for example, polyethylene, polypropylene, polybutene, polymethylpentene, polyolefin resins such as olefinic thermoplastic elastomer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene- (meth) acrylic acid ( Ester) copolymer, ethylene- (meth) acrylic acid copolymer metal neutralized product (so-called ionomer resin), olefinic copolymer resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, etc. Polyvinyl resin, polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polyarylate, polyester resin such as polycarbonate, polymethacrylic acid Acrylic resins such as chill, polyethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyacrylonitrile, polymethacrylonitrile, styrene such as polystyrene, AS resin, ABS resin, etc. -Based resins, polyamide-based resins such as 6-nylon and 6,6-nylon, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer It may be a fluorine-based resin or the like such as a combination, or a mixture or copolymer of a plurality of kinds thereof. Further, the foamed layer can also be formed by a laminate of a plurality of layers made of the same or different thermoplastic resins by a multilayer extrusion method or the like.

In the present invention, the kind of the foaming agent added to foam the thermoplastic resin is not particularly limited, and may be appropriately selected from conventionally known foaming agents. Specifically, as a conventionally known foaming method of a thermoplastic resin, generally, a chemical foaming method using a chemical substance (chemical foaming agent) having a property of generating a gas by thermal decomposition or a chemical reaction, It can be classified into a physical foaming method that utilizes a phenomenon in which a liquid having a low boiling point or a gas liquefied under high pressure (physical foaming agent) is vaporized by the action of heat. Examples of the chemical foaming agent used in the former include sodium bicarbonate (baking soda), ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals (aluminum, magnesium, etc.), azide compounds (sodium azide, etc.)
Inorganic foaming agents such as azo type (azodicarbonamide, azobisisobutyronitrile, etc.), nitroso type (dinitrosopentamethylenetetramine, dimethyldinitrosoterephthalamide, etc.), hydrazide type (p, p'-oxybis Organic blowing agents such as benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, etc.) can be used alone or in any combination of plural kinds. In addition, especially when high expansion ratio of more than 2 times is required, the physical foaming method is suitable, and the physical foaming agent used at that time is carbon dioxide gas (carbon dioxide) or aliphatic carbonization. Hydrogen (propane, butane, pentane,
Inert gases such as hexane and heptane) and chlorofluorocarbons (so-called CFCs) are mainly used. Also, in foaming extrusion molding by the physical foaming method, a chemical foaming agent may be used together for the purpose of adjusting the cell shape of the foamed body.

The foamed resin material 12 includes, in addition to the above-mentioned thermoplastic resin and foaming agent, if necessary, for example, a heat stabilizer, an acid neutralizer, an ultraviolet absorber, a light stabilizer, a colorant (dye, pigment, etc.). Various additives such as a filler, an antistatic agent, a lubricant, a nucleating agent, a flame retardant, an antiblocking agent, a light-scattering agent for semi-transparency, and a gloss adjusting agent may be appropriately added. Among these additives, the heat stabilizer is a hindered phenol type, a sulfur type, a phosphorus type, etc., the acid neutralizing agent is a stearic acid metal salt, hydrotalcite, etc., and the ultraviolet absorber is a benzotriazole type, a benzoate. -Based, benzophenone-based, triazine-based, etc., light stabilizers such as hindered amine-based, flame retardants as halogen-based, phosphorus-based, chlorine-based, etc., and fillers as inorganic-based (calcium carbonate, silica, titanium oxide, barium sulfate, Zinc oxide, alumina,
Talc, clay, magnesium silicate, potassium titanate, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, iron oxide, carbon black, metal powder, carbon fiber, glass fiber, etc. or organic type (nylon type, polycarbonate type, polyurethane type) , Acrylic, wood wool, wood powder, paper powder, etc.) as a lubricant, hydrocarbon-based, fatty acid-based,
Higher alcohol type, fatty acid amide type, metal soap type, ester type, etc., carboxylic acid metal salt type, sorbitol type, phosphoric acid ester metal salt type, etc. as nucleating agent, condensed azo type, insoluble azo type, quinacridone as pigment System, isoindolinone system, anthraquinone system, imidazolone system, phthalocyanine system, carbon black, titanium oxide, iron oxide system, cobalt blue, pearl pigment (titanium oxide coated mica etc.), etc. It can be used in any combination.

The material of the cover sheet 13 used in the present invention is not particularly limited. When it comes into contact with the foamed resin material 12 in a heat plasticized state extruded from the extrusion die 11,
It is considered that a material that is easily melted or softened by the heat is unsuitable, but in reality, the covering sheet 13 is in contact with the foamed resin material 12 in a heat-plasticized state and, at the same time, strongly adheres to the inner wall surface of the cooling sizing die 14. Since it is pressed and passes through the cooling sizing mold 14 while being constantly cooled, there is no particular problem even if the softening temperature thereof is equal to or lower than that of the foamed resin material 12, and the softening temperature is at least around room temperature. Any sheet-shaped body may be used as long as it has strength to withstand the tension of the machine 16. Specific examples include papers, synthetic resin-impregnated papers, synthetic resin films, metal foils, wood veneers, and the like, or laminates of two or more thereof. Among them, as the material of the synthetic resin film, for example, the same materials as those mentioned as the thermoplastic resin which is the main component of the foamed resin material 12 can be used.

In the present invention, in particular, when the cover sheet 13 made of a thermoplastic resin of the same type as the thermoplastic resin which is the main component of the foamed resin material 12 is used, the cover sheet 13 is specially bonded to the foamed resin material 12. In addition to being able to easily form a strong bond by contact with the foamed resin material 12 in a heat-plasticized state, it is possible to process the foamed resin extruded molded article 19 with a covering sheet to be produced thereafter without any special treatment. When treating unnecessary scraps generated inside and waste materials after use, it is not necessary to separate the covering sheet 13 and the foam layer made of the foam resin material 12, and the powder is crushed or heat-melt kneaded as it is to There is an advantage that it can be reused (recycled) as a resin molding material for the same purpose or another purpose without losing excellent characteristics.

As a specific example, when it is used as a building material such as a wall material, a floor material, or a ceiling material in a building such as a house, it has excellent strength, physicochemical stability, economic efficiency, and molding process. In terms of properties, it is desirable that the foamed resin material 12 and the cover sheet 13 are mainly composed of polypropylene resin.

As the polypropylene resin used here, general homopolypropylene, random polypropylene, block polypropylene, propylene-α-olefin copolymer, etc. are mainly used, and if necessary, polybutene, polyisoprene, ethylene-propylene. One or more selected from copolymers, ethylene-vinyl acetate copolymers, ethylene-α-olefin copolymers, ethylene-ethyl acrylate copolymers and acid-modified products thereof, ionomer resins, etc. are appropriately added. A mixed resin composition or the like can be used. However, when mixing and using multiple types of resins, in order to ensure the physical properties after recycling, select a combination of resins with the best compatibility or add a compatibilizer, etc. Consideration is required.

For the above-mentioned applications of the building material, for example, machinability with a saw, a cone, a chisel, etc., workability equivalent to that of wood, which is the most popular building material in the past, is required such as nailability and screwing property. In many cases. In order to impart such performance to the polypropylene resin, it is most desirable to add a wood filler to the resin. For the above purpose, the wood-based filler may be added mainly to the foamed resin material 12, and may or may not be added to the covering sheet 13. The wood-based filler is added to the foamed resin material 12 even if the cut surface of the manufactured foamed resin molded product with a cover sheet 19 has a wood-like appearance, so that the cut surface is exposed. Since there is little discomfort in appearance and the thermal conductivity is lowered in combination with foaming, there are advantages such as a warm touch similar to that of wood.

The material of the above-mentioned wood-based filler can be selected without any particular limitation, but in general, wood is broken by a cutter mill or the like, and this is crushed by a ball mill, impeller mill or the like to obtain a fine powder. Use the one in the shape of wood (wood flour). Further, the blending amount is 1
In the case of a high compounding amount of more than 100 parts by weight with respect to 00 parts by weight, dispersibility in the resin is particularly important, and it is preferable to use a granular wood-based filler having relatively few cilia. As the wood-based filler having a small amount of cilia, abrasive powder obtained by polishing a particle board or the like is mainly used. The amount of the wood-based filler can be appropriately selected, and the optimum amount varies depending on the use of the decorative material, but generally 20 to 400 parts by weight with respect to 100 parts by weight of the thermoplastic resin. It is designed within the range of parts.

The kneading method of the thermoplastic resin and the wood-based filler when the wood-based filler is added to the thermoplastic resin constituting the foamed resin material 12 is not particularly limited, but the kneading is carried out by a Henschel mixer and is then mixed with a pelletizer. A method of pelletizing, a method of mixing and pelletizing with a twin-screw extrusion kneader and the like are common. Further, when recycling the molded product manufactured by the manufacturing method of the present invention, it is possible to add a wood filler, a thermoplastic resin, various additives, etc. to the crushed molded product, if necessary. . The kneading method and pelletizing method in that case are also the same as those described above and are not particularly limited.

According to the manufacturing method of the present invention, since the covering sheet 13 is attached at the same time as the extrusion molding of the foamed resin material 12, the space between the inner surface of the cooling sizing die 14 and the foamed resin material 12 in the heat plasticized state. In addition, due to the presence of the cover sheet 13 in the solid state, it is difficult to perform foaming extrusion molding by the conventional SELCA method, such as a soft polypropylene resin or a polypropylene resin to which a wood-based filler is added. It is possible to satisfactorily perform foaming extrusion molding without generation of the resin, which allows the resin to be designed according to the required physical properties depending on the part to be used, and has an advantage that it can be applied to various parts in a building or the like.

When used for the above purpose, the important point about the covering sheet 13 (decorative sheet) to be laminated is as follows.
Mainly, a thermoplastic resin similar to the foamed resin material 12 is used, the back surface of the decorative sheet can be heat-bonded to the foamed molded product, and design patterns such as wood grain pattern, stone pattern, cloth pattern, and abstract pattern. As a result, the structure of the decorative sheet itself is not restricted. For example, a single-layer decorative sheet printed on the surface of the coloring sheet or the front surface or the back surface of the transparent sheet, a transparent sheet on the printing surface of the sheet printed on the coloring sheet, a dry lamination method, an extrusion lamination method, a heat lamination method, etc. From the multi-layered decorative sheet etc.
It can be appropriately selected according to the application.

The ink used for printing the design pattern is appropriately selected from nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acryl, polyester, etc. alone or each modified product as a binder. do it. There is no problem whether they are water-based, solvent-based or emulsion-type, and
Either a liquid type or a two-liquid type using a curing agent can be arbitrarily selected. Further, it is also possible to cure the ink by irradiating it with ultraviolet rays or electron beams. Among them, the most general method is a method in which urethane ink is used and cured with isocyanate. In addition to these binders, pigments, colorants such as dyes, extender pigments, solvents, and various additives contained in ordinary inks are added. Particularly frequently used pigments are condensed azo, insoluble azo, quinacridone,
Examples include pearl pigments such as isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide and mica.

Also, in any of the decorative sheets, the back surface is a resin layer mainly composed of polypropylene (in the case of a colored sheet in a multi-layer decorative sheet) for bonding with the foamed resin material 12, or It is important that it is a resin layer that can be heat-bonded to polypropylene (in the case of a printing layer or an adhesive layer in a single-layer decorative sheet). In particular, in consideration of recyclability, it is desirable that the resin layer mainly containing polypropylene resin is present on the outermost surface. Also, as is well known in the field of such decorative sheets,
The surface may be provided with a top coat for surface protection or gloss adjustment, or a conduit expression by an embossing method or a gloss matting method. Further, as the additive used for the thermoplastic resin layer (coloring sheet, transparent sheet) in this decorative sheet, the same additives as in the case of the foamed resin material 12 can be appropriately used.

[0032]

[Example] <Example 1> Thickness 1 formed by mixing a pigment such as iron oxide or titanium oxide into a random polypropylene resin to form a film.
The surface of a 00 μm colored polypropylene resin sheet is subjected to wood grain printing using a urethane-based printing ink, and a transparent homopolypropylene resin is laminated on the printed surface to a thickness of 100 μm by an extrusion laminating method. A top coat made of a two-component curing type urethane resin was applied to produce a decorative sheet for use as a cover sheet.

On the other hand, 70 parts by weight of a commercially available low melt tension homopolypropylene resin, 30 parts by weight of a maleic acid-modified homopolypropylene resin, and a wood-based filler (wood is broken by a cutter mill and crushed by a ball mill to obtain a fine powder). 400 parts by weight of wood powder (having an average particle size of about 20 μm) was kneaded and pelletized by a biaxial extrusion kneader. 100 parts by weight of the pellets thus obtained was mixed with 3 parts by weight of a homopolypropylene resin-based masterbatch containing 45% by weight of a baking soda-citric acid-based chemical foaming agent, and used in the production apparatus having the configuration shown in FIGS. 1 and 3. It is put into an extruder, and the cross-sectional shape has a height of 2. in the center at an extrusion speed of 1 m / min from an extrusion die.
It is extruded into a rectangular shape having a height of 5 mm and a width of 300 mm and a rectangular shape having a hollow portion of 5 mm and a width of 295 mm, and this is used as a cooling sizing mold in which the cross-sectional shape of the inner wall surface is a rectangle of 5.2 mm in height and 300 mm in width. At the same time as the introduction, the above decorative sheet is coated and adhered on the upper surface, and after cooling and taking-off, the
It was cut to 00 mm. In this way, the foamed resin extruded product with a covering sheet of the present invention that can be used as a flooring material, a wall material, or the like can cause a molding failure accident such as resin clogging in a cooling sizing die or deformation / breakage during take-up. And could be manufactured satisfactorily.

<Comparative Example 1> In the above-mentioned Example 1, the cross-sectional shape of the inner wall surface of the cooling sizing die is 5 mm high.
A rectangular resin having a width of 300 mm was used, and when the foamed resin material was introduced into the cooling sizing mold, the coating adhesion of the decorative sheet was omitted, and otherwise the foamed resin extrusion was performed under the same conditions as in Example 1 above. An attempt was made to produce a molded body. However, since the melt viscosity of the foamed resin material extruded in the heat plasticized state is too low, it is easy to be clogged inside the cooling sizing die,
If this was attempted to be forcibly taken by a take-up machine, the foamed resin material would be stretched inside the cooling sizing die, and eventually it would break, making it impossible to obtain a good foamed resin extruded product.

Comparative Example 2 In Comparative Example 1 described above, the conditions under which the extrusion rate of the foamed resin material (that is, the take-up rate of the molded body) was lowered and favorable foaming extrusion molding was possible without causing a molding failure accident. When I looked for it, the extrusion speed was 0.2
It was found that good molding cannot be achieved unless the pressure is reduced to m / min.

[0036]

According to the method for producing a foamed resin extruded product with a covering sheet of the present invention, a foamed resin material extruded from an extrusion die in a heat-plasticized state is introduced into a cooling sizing die to be cooled and solidified. At the same time, in the cooling sizing die, since at least a part of the surface of the foamed resin material is coated with a coating sheet, at least in the portion where the coating sheet is coated, the foamed resin material in a heat plasticized state is The cooling force does not come into contact with the inner wall surface of the cooling sizing die, and the frictional force between the foamed resin material and the inner wall surface of the cooling sizing die is reduced by that amount, and the solid material coated on the surface of the foamed resin material is reduced. By using the tension applied to the covering sheet in the state, the foamed resin material is taken from the cooling sizing die, and the foamed resin material is clogged inside the cooling sizing die. Without or to form, smoothly it becomes easily possible 引取Ru with cover sheet from the cooling sizing die. In this way, the foam extrusion molding method can be applied to foamed resin molded products that use a thermoplastic resin that is softer than previously possible, and foamed resin molded products that have higher expansion ratios and complex cross-sectional shapes than before. As a result, the foamed resin molded article can be molded more favorably and efficiently, so that it can contribute widely to further weight reduction of the foamed resin molded article, high heat insulation, cost reduction, functional improvement, expanded applications, and the like.

In particular, when the foamed resin material is extruded and molded by the selka method, the extruded foamed resin material is cooled by the rigidity of a high-density skin layer having an extremely low expansion ratio formed on the surface layer portion. It is easy to withstand the frictional force with the sizing die, and this, combined with the action of the covering sheet described above, makes it possible to easily and satisfactorily and stably produce a foamed resin molded product having a high expansion ratio and a complicated cross-sectional shape. Become. Further, in the foam extrusion molding by the selka method, the foamed resin material extruded, in the cooling sizing mold, foaming progresses toward the internal cavity portion, and as a reaction thereof, the surface layer part of the cooling sizing mold is Toward the inner wall,
That is, since a pressure that strongly presses against the covering sheet is generated at the place where the covering sheet is covered, there is also an advantage that the foamed resin material and the covering sheet can be firmly adhered.

[Brief description of drawings]

FIG. 1 is a schematic process diagram illustrating an example of a method for producing a foamed resin extruded product with a cover sheet according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view illustrating a state near a joint portion between an extrusion die and a cooling sizing die in a manufacturing method of the present invention by a normal method.

FIG. 3 is a partially enlarged cross-sectional view illustrating a state near a bonding portion between an extrusion die and a cooling sizing die in a manufacturing method of the present invention by a selka method.

[Explanation of symbols]

10 extruder 11 Extrusion die 12 Foamed resin material 13 Cover sheet 14 Cooling sizing mold 15 Cooling tank 16 pick-up machine 17 cutting table 18 cutting blade 19 Foamed resin extruded product with cover sheet 20 Torpedo 21 Skin layer 22 Highly foamed layer 23 Skin layer

Claims (2)

[Claims] 1. A method for producing a foamed resin extruded product with a covering sheet, which comprises coating a covering sheet on at least a part of the surface of a foamed resin extruded product, which is extruded from an extrusion die in a heat plasticized state. A foaming resin material is introduced into a cooling sizing die to be cooled and solidified, and at the same time, at least a part of the surface of the foaming resin material is coated with a coating sheet inside the cooling sizing die. A method for producing a foamed resin extruded product with a sheet. 2. The method for producing a foamed resin extruded product with a covering sheet according to claim 1, wherein the foaming resin material is extruded and molded by a selka method.