JP3915555B2 - Wood resin foam molding and decorative material - Google Patents

Description

【００５８】
上記木質樹脂発泡成形体の表面にコロナ放電処理を施した後、その上面及び両側面に、木目印刷が施されたポリプロピレン樹脂系化粧シートをラッピング加工法にて積層して、本発明の化粧材を作製した。この化粧材は、床材として好適に使用可能であった。
【００５９】
比較例１
上記実施例１において、木質樹脂組成物の配合を下記のとおり変更し、その他は同一条件にて木質樹脂発泡成形体を成形した。
【００６０】

【００６１】
比較例２
上記実施例１において、木質樹脂組成物の配合を下記のとおり変更し、その他は同一条件にて木質樹脂発泡成形体を成形した。
【００６２】

【００６３】
比較例３
上記実施例１において、木質樹脂組成物の配合を下記のとおり変更し、その他は同一条件にて木質樹脂発泡成形体を成形した。
【００６４】

【００６５】
評価
上記実施例１及び比較例１〜３について、成形時の状況（引取り性、スクリューへの樹脂付着）及び成形品の仕上がり（厚みムラ、表面性）を評価したところ、下表の通りであった。但し、比較例１は連泡が生じて表面が凹凸状をなし、比較例２、３は木質樹脂組成物が成形機のスクリューにこびりついて成形不能であった。
【００６６】

【００６７】
【発明の効果】
以上詳細に説明した様に、本発明の木質樹脂発泡成形体及び化粧材は、ポリオレフィン系樹脂及び木質系充填剤を主成分とする発泡成形体であることにより、木材に近似した外感や触感等の質感を備え、しかもリサイクル適性を有することは勿論のこと、上記ポリオレフィン系樹脂及び木質系充填剤に、さらにアクリル変性ポリテトラフルオロエチレン系相溶化剤及びマレイン酸変性ポリプロピレン系相溶化剤を所定量配合した木質樹脂組成物を使用したことにより、ポリオレフィン系樹脂と木質系充填剤との結着力が強く、連泡を発生せずに均一に発泡可能であり、しかも、溶融張力が高く発泡が容易で、分散性や混練性が良好で、ポリオレフィン系樹脂が結晶化し易く、金属製のスクリュー等の機械部品に接着しにくいなど、発泡成形性に優れているので、木質系充填剤がポリオレフィン系樹脂と良好に結着しつつ均一に分散していると共に均一に発泡した、機械的強度や表面性、厚み精度等に優れた、しかも、成形不良事故を発生することなく、安定的且つ能率的に製造可能な木質樹脂発泡成形体であるという、実用上の顕著な利点を有するものである。
【図面の簡単な説明】
【図１】本発明の木質樹脂発泡成形体及び化粧材の実施の形態を示す側断面図である。
【符号の説明】
１ 木質樹脂発泡成形体
１１ 芯部
１２ 表層部
１３ ポリオレフィン系樹脂
１４ 木質系充填剤
１５ 木質樹脂組成物
１６ 気泡
２ 化粧シート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wood resin foam molded body used for building interior materials such as floor materials, wall materials, ceiling materials, and the like, surface materials for home appliances, and cosmetic materials using the same.
[0002]
[Prior art]
Conventionally, many decorative materials are made by attaching decorative paper or decorative sheets, etc. that have been designed by printing to natural veneer, paper, or synthetic resin sheets to woody base materials such as plywood and fiberboard. It is used. However, these decorative materials have physical property problems such as worm-eaten and corrosion of the wooden base material, and are difficult to recycle, and most of them are treated by landfill or incineration. In addition, although there is also a decorative sheet pasted on a resin base material by profile extrusion etc., these decorative materials are not defective due to the wooden base material, even if it looks like wood, with a decorative sheet of wood grain design, There are problems such as lack of wood texture in terms of specific gravity and rigidity, and difficulties in workability such as cutting and nailing, and it can be used only in limited areas.
[0003]
In recent years, many attempts have been made to use wood resin moldings containing thermoplastic resins and wood-based fillers (wood flour, etc.) for applications such as building interior materials, flooring materials, fittings, and home appliance surface materials. Yes. As the thermoplastic resin, polyvinyl chloride resin was the mainstream at first, but problems such as incineration and plasticizers have been pointed out, and in recent years there is no such problem and it is being replaced with an inexpensive polyolefin resin. This wood resin molding has an appearance similar to wood and is excellent in recyclability, cutting, and nailing, but the specific gravity increases as the content of wood powder increases. There is a problem that lightness and heat insulation, which are advantages, are impaired. Therefore, by foaming a wood resin composition containing a thermoplastic resin and a wood filler, it has a lightness, heat insulation, warm and elastic tactile feel close to wood, and it can be used for cutting, nailing, etc. Attempts have also been made to provide a wood-resin foam-molded product with further improved processability. However, a thermoplastic resin highly filled with a wood-based filler has a problem that foam moldability is poor, and it is difficult to efficiently and stably produce a foam molded article having good quality.
[0004]
The main reason for this is that wood based fillers are composed of cellulose fibers rich in hydrophilicity, whereas thermoplastic resins such as polyolefin resins are generally hydrophobic and have low affinity for both. This is because the dispersibility of the wood filler is poor. Then, in order to raise both affinity and to disperse | distribute a wood type filler favorably, the mixing | blending of various compatibilizing agents is tried. Specific examples of the compatibilizer include unsaturated carboxylic acid-modified polyolefin resins such as maleic acid-modified polyolefin resins, acrylic acid-modified polyolefin resins, itaconic acid-modified polyolefin resins, and glycidyl methacrylate-modified polyolefin resins. Epoxy-modified polyolefin resin such as hydroxy group, hydroxyl group-modified polyolefin resin such as hydroxyethyl methacrylate-modified polyolefin resin, olefin-polar group-containing monomer copolymer such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, etc. Resins, acrylic-modified polytetrafluoroethylene resins, cationic surfactants, anionic surfactants, amphoteric surfactants, nonionic surfactants, and the like have been tried.
[0005]
However, none of the above-mentioned various compatibilizers can be said to have sufficient performance in all aspects for the production of a woody resin foam molded article. For example, a wood resin composition containing a polyolefin resin and a wood filler as a main component and added with a maleic acid-modified polypropylene compatibilizer is compatible with the hydroxyl groups on the surface of the wood filler during kneading at a high temperature. Since the ester bond is formed and bonded firmly with the carboxyl group of the agent, the polypropylene resin part that is the main skeleton of the compatibilizer is well compatible with the polyolefin resin that is the main component of the wood resin composition. In addition, the binding force between the polyolefin resin and the wood filler is increased, and the dispersibility is improved. However, if a material having a high degree of acid modification is used in order to obtain a sufficient compatibilizing action, the adhesiveness to a metal or the like is also increased. For example, a resin sticks to a screw in an extruder, and kneading and molding become difficult. Further, the maleic acid-modified polypropylene-based compatibilizing agent has a side effect of lowering the melt tension of the wood resin composition, and there is a problem that it becomes difficult to form a foam cell during foam molding.
[0006]
On the other hand, for example, acrylic modified polytetrafluoroethylene-based compatibilizer is a kind of fluorine-based resin, and since there are fluorine atoms on the surface of the resin molecule, the cohesive force is low, and fibril deformation occurs when shearing force is applied. It has the property of being intertwined in a network, and the fibrils are efficiently generated and dispersed by acryl modification (the fibrils become thinner and the number increases), so that the fine fibrils are entangled in the resin. The particles of the system filler are pulled apart and dispersed to improve the kneadability and dispersibility of the woody resin composition. At the same time, the entanglement effect of the fibrils improves the melt tension of the woody resin composition to facilitate foaming, and the improvement of the kneadability facilitates the crystallization of the polyolefin-based resin and increases the strength of the foamed molded product. However, on the other hand, the wood-based filler is only mechanically dispersed in the polyolefin-based resin, so the binding force between the polyolefin-based resin and the wood-based filler is weak. Since the agent solidifies into the gap between the two and foams on the spot, it is easy to generate open bubbles, which causes the foamed state inside the foamed molded product to be uneven, There are problems in that physical properties vary and voids due to continuous bubbles are easily generated, resulting in uneven thickness.
[0007]
Detailed explanations of other compatibilizers are also omitted, but there are advantages and disadvantages in performance, and compatibilizers that give a good wood resin composition in terms of both product quality performance and productivity are still found. Not reached. Therefore, it has a wood texture such as appearance, specific gravity, and tactile sensation similar to wood, processability such as cutting and nailing, etc., and can be reused repeatedly, and stable and efficient products with good quality The present situation is that a wood resin foam molded article excellent in economic rationality that can be easily manufactured has not yet been obtained.
[0008]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-described problems in the prior art, and has recyclability in addition to wood texture and processability similar to wood, and also has good foam moldability, high It is an object of the present invention to provide a wood resin foam molded article that can easily produce a quality product, and a decorative material using the same.
[0009]
[Means for Solving the Problems]
The wood resin foam molded body of the present invention is a wood resin foam molded body obtained by foam molding a wood resin composition mainly composed of a polyolefin resin and a wood filler, wherein the wood resin composition is a polyolefin resin. The main component is 80 to 15% by weight and 20 to 85% by weight of a wood filler, and 0.5 to 10 parts by weight of an acrylic-modified polytetrafluoroethylene compatibilizer and maleic acid per 100 parts by weight of the wood filler. It contains 0.5 to 5 parts by weight of a modified polypropylene compatibilizer.
[0010]
In particular, in the woody resin foam molded article, the maleic acid-modified polypropylene compatibilizer has a maleic acid modification rate of 4% or more.
[0011]
In particular, the above-mentioned wood resin foam molded article has a multilayer structure in which a non-foamed or low foaming ratio surface layer part is laminated on at least a part of the surface of the core part having a high foaming ratio. It is.
[0012]
In particular, the woody resin foam molded body is characterized by being molded by the Celca method.
[0013]
The decorative material of the present invention is characterized in that a decorative sheet mainly composed of a polyolefin-based resin is laminated on at least a part of the surface of the wood resin foam molded article.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the wood resin foam molded article 1 of the present invention appropriately comprises a wood resin composition 15 mainly composed of a polyolefin resin 13 such as polypropylene and a wood filler 14 such as wood powder. It is formed into a desired shape while being foamed (by forming bubbles 16 inside) by adding a foaming agent, etc., and as its use, it can be used as it is as a structural material for construction or furniture, or The decorative sheet 2 is laminated on at least a part of the surface (in principle, a part that can be seen from the user side in the state of use) and used as a decorative material for construction or furniture.
[0015]
In addition to the polyolefin resin 13 and the wood filler 14, the wood resin composition 15 includes two types of an acrylic modified polytetrafluoroethylene compatibilizer and a maleic acid modified polypropylene compatibilizer. It is important in the present invention to contain the compatibilizing agent.
[0016]
That is, as described above, the maleic acid-modified polypropylene compatibilizer has the advantage that it is extremely effective in improving the binding force between the polyolefin resin 13 and the wood filler 14, but is easy to adhere to metals and the like. In addition, there are drawbacks that make it difficult to process by a kneading and molding machine such as an extruder, and make it difficult to form foamed cells in order to reduce the melt tension. One acrylic modified polytetrafluoroethylene-based compatibilizer is, While it is effective for improving the dispersibility of the wood-based filler, improving the foamability by increasing the melt tension, and improving the crystallinity of the polyolefin-based resin, the polyolefin-based resin 13 and the wooden-based filler are effective. 14 has a weak binding force, and voids due to continuous bubbles are likely to occur, resulting in a non-uniform foaming state, and mechanical properties such as mechanical strength and dimensions such as thickness are likely to be uneven. There is.
[0017]
On the other hand, in the present invention, the above-mentioned acrylic modified polytetrafluoroethylene-based compatibilizer and the maleic acid-modified polypropylene-based compatibilizer are used in combination, so that each defect is compensated by the other advantage, and the wood-based filling Since both the dispersibility of the agent 14 and the binding force to the polyolefin resin 13 are enhanced, and the kneadability is also improved, both the wood filler 14 and the foaming agent are uniformly dispersed, and the continuous foam In addition, the foamed state is made uniform, and the foam tension is improved by improving the melt tension and crystallinity of the polyolefin-based resin 13 and the foam moldability is improved. The uniformity of the dispersion state and the foaming state of the system filler 14 and the improvement of the crystallinity of the polyolefin resin 13 are combined, so that the physical properties such as mechanical strength and the precision of the dimensions such as the thickness are combined. Excellent woody resin foam-molded body also can be easily obtained.
[0018]
In addition, the acrylic modified polytetrafluoroethylene-based compatibilizing agent containing fluorine atoms makes it difficult to adhere to mechanical parts such as metal screws due to the effect as an internal mold release agent specific to fluorine-based compounds. Combined with the improvement in kneadability by entanglement, the processability by a kneading and molding machine such as an extruder is improved, and the wood resin foam molded body 1 can be stably and efficiently manufactured.
[0019]
In order to exert a good balance between the action of the acrylic-modified polytetrafluoroethylene-based compatibilizer and the action of the maleic acid-modified polypropylene-based compatibilizer, the balance of the blending ratio of both to the wood resin composition 15 is also important. .
[0020]
The specific blending ratio needs to be appropriately determined in consideration of the types and blending ratios of the polyolefin resin 13 and the wood filler 14, molding conditions, required characteristics of the product, and the like. In the wood resin composition 15 mainly composed of 80 to 15% by weight of resin and 20 to 85% by weight of the wood filler, the acrylic modified polytetrafluoroethylene compatibilizer is 0 per 100 parts by weight of the wood filler. It is desirable to blend 5 to 10 parts by weight and about 0.5 to 5 parts by weight of the maleic acid-modified polypropylene compatibilizer.
[0021]
When the blending amount of each compatibilizer is less than each lower limit value, the effect of the compatibilizer is not sufficiently expressed, and when the other compatibilizer is blended alone, or the compatibilizer is not blended at all. The result is similar to the case. On the other hand, when the blending amount of each compatibilizer exceeds the respective upper limit values, not only the improvement of the action as the compatibilizer can be expected, but the blending ratio of the polyolefin resin 13 as the matrix component of the wood resin composition 15 is not limited. This is because the mechanical strength, heat resistance, moldability, and the like of the obtained wood resin molded body 1 may be reduced because of the relative decrease.
[0022]
Moreover, in order to fully exhibit the action of the maleic acid-modified polypropylene compatibilizer, it is necessary to pay attention to the maleic acid modification rate. This is because if the maleic acid modification rate is too low, the binding force with the wood filler 14 is low and the effect as a compatibilizing agent is poor. From such a viewpoint, the maleic acid modification rate of the maleic acid modified polypropylene compatibilizer used in the present invention is preferably 4% or more.
[0023]
As a specific molding method of the woody resin foam molded body 1 of the present invention, any conventionally known resin molding method such as an extrusion molding method, an injection molding method, a hollow molding method, or the like can be applied. Extrusion molding is most suitable for continuous molding of long shaped bodies for use in construction and furniture structural materials and decorative materials. As the extrusion molding method, in addition to the T-die extrusion molding method for molding a sheet-shaped or plate-shaped molded body, a profile extrusion molding method for molding a molded body having a complicated cross-sectional shape can also be used.
[0024]
For structural and decorative materials for construction and furniture, high foaming is required from the standpoints of weight reduction, high heat insulation, cost reduction, etc., while the expansion ratio is from the standpoint of rigidity and surface strength. Suppression is also required. As a technique for satisfying such contradictory requirements together, as shown in FIG. 1, a multilayer structure in which a non-foamed or low foaming magnification surface layer part 12 is formed on the surface of a core part 11 having a high foaming magnification, etc. Can be mentioned.
[0025]
In the example shown in FIG. 1, the surface layer portion 12 is provided so as to surround the entire surface of the core portion 11. However, the multi-layer structure is not limited to this, and the surface layer portion 12 is made of wood. It suffices that the resin foam molded body 1 is formed at least in a portion where rigidity, surface strength, and the like are required. For example, in the case of a flat wall material or floor material, the surface layer portion 12 may be formed only on the indoor side surface (upper surface) of the core portion 11 or from the indoor side surface (upper surface) to a part or all of the end surface. .
[0026]
As a manufacturing method of the wood resin foam molded article 1 having such a multilayer structure, for example, a plurality of types of foamable wood resin compositions 15 with different blending amounts of foaming agents are separately molded by an extrusion molding method, an injection molding method, or the like. May be a pasting method or a sequential extrusion method or a co-extrusion method using the above-mentioned plural types of foamable wood resin composition 15, but a single type of foamable wood resin composition 15 is used. As a molding method that can be molded continuously and stably in a single process, the Celca method is most preferable.
[0027]
With the Celca method, an extrusion mold having an exit dimension that is substantially the same as or slightly smaller than the inlet dimension of the cooling sizing mold was used, and the outlet of the extrusion mold and the inlet of the cooling sizing mold were almost adhered to each other. In the state, by extruding the foamable resin composition from the extrusion mold, the foamable resin composition is introduced into the cooling sizing mold in a state where the foaming hardly proceeds, and the cooling sizing mold is mainly used. It is a foaming extrusion molding method in which foaming is performed inside.
[0028]
Depending on the thickness of the molded product and the expansion ratio, an extrusion die with a torpedo (also called mandrel or core) is used inside the extrusion die, or resin is extruded through a hole provided in the torpedo. In some cases, a technique is used.
[0029]
In this Celca method, the surface layer portion of the molded body is pressed against the inner surface of the cooling sizing mold immediately after being extruded from the extrusion mold, and is therefore rapidly cooled. The surface layer part of non-foaming or low foaming ratio is automatically formed on the surface and the core part of high foaming ratio is automatically formed inside, which is also called the inward forming process. .
[0030]
In the Celca method, the difference between the outlet shape of the extrusion mold and the inlet shape of the cooling sizing mold is made different depending on the cross section, and the surface of the foamable resin composition extruded from the extrusion mold is cooled and sized. The surface layer of non-foamed or low-foaming ratio is applied to only a part of the surface of the foamed molded article by changing the cooling rate depending on the surface part, such as by changing the timing of contacting the inner surface of the mold depending on the surface part. It is also possible to form a part.
[0031]
The thickness and foaming ratio of the core 11 and the surface layer portion 12 of the wood resin foam molded body 1 are arbitrary depending on the intended use. For example, if it is a flooring for indoors such as a house, the rigidity and surface Considering the balance of various aspects such as strength, scratch resistance, pressure scar resistance, heat insulation, flexibility, tactile sensation, walking feeling, flexibility, and workability, the thickness of the wood resin foam molded body 1 is about 2 to 30 mm. (Particularly about 3 to 15 mm), the expansion ratio of the core portion 11 is about 1.2 to 3.0 times, the expansion ratio of the surface layer portion 12 is about 1.0 to 1.1 times, and the thickness of the surface layer portion 12 is 0.00. The thickness of the core 11 is preferably about half or more of the entire thickness.
[0032]
In the present invention, examples of the polyolefin resin 13 used for the wood resin foam molded article 1 include polyethylene, polypropylene, polybutene, polyisoprene ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α olefin copolymer. A polymer, a propylene-α-olefin copolymer, an ethylene-ethyl acrylate copolymer, an acid-modified one of these for the purpose of improving adhesiveness, or an ionomer can be selected as appropriate. It doesn't matter.
[0033]
Among them, homopolypropylene, random polypropylene, block polypropylene, propylene-α-olefin copolymer, etc. in terms of rigidity, surface hardness, dimensional stability (low linear expansion coefficient) required for structural materials and decorative materials, etc. The polypropylene resin is most suitable.
[0034]
Moreover, since it is necessary to foam the woody resin foam molding 1 in this invention, the polyolefin resin 13 is required to have foamability. In general, in order to improve foamability, it is desirable that the melt tension of the polyolefin resin 13 is high. In particular, in the case where there is a concern about outgassing when the wood filler 14 is highly filled, long chains by electron beam crosslinking are used. It is desirable to adjust the melt tension as necessary by a known method such as the use of a grade with branching introduced, the control of the molecular weight distribution, or the blend of a fluorine-based additive that increases the melt tension. Note that the use of the Celca method described above has an advantage that good foaming is relatively easy even with a resin having a low melt tension, as compared with a sheet foam molding method and a normal profile foam extrusion method.
[0035]
In the present invention, the material of the wood-based filler 14 used for the wood resin foam molded body 1 can be selected without particular limitation, but generally, the wood is broken by a cutter mill or the like. These are pulverized by a ball mill, an impeller mill, or the like to obtain a fine powder (wood powder).
[0036]
The average particle size of the wood filler 14 is preferably about 1 to 200 μm, and more preferably 10 to 150 μm. Those having an average particle size of less than 1 μm are difficult to handle, and especially when the amount of the wood-based filler is large, if the dispersion into the resin is poor, the mechanical strength of the wood-resin foamed molded product to be produced Decrease occurs. Moreover, it is because the uniformity, planarity, and mechanical strength of a molded product will fall when larger than 200 micrometers.
[0037]
In the present invention, any known technique can be used as the technique for foaming the woody resin composition 15. In general, chemical foaming can be classified into chemical foaming, which generates gas by thermal decomposition or chemical reaction, and physical foaming, which heats low-boiling liquids to vaporize them, and chemical foaming agents include inorganic sodium bicarbonate and ammonium carbonate. Ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals, azide compounds, etc., and organic foaming agents such as azo, nitroso, hydrazide, etc. can be used in any combination. In particular, physical foaming is mainly used for foaming at a high foaming ratio exceeding 2 times, and carbon dioxide gas and aliphatic hydrocarbons are mainly used as foaming agents. In addition, a chemical foaming agent is often used in combination with physical foaming to adjust the cell shape of the foam.
[0038]
In the present invention, the wood resin composition 15 used for molding the wood resin foam molded article 1 includes a heat stabilizer, an acid neutralizer, and an ultraviolet absorber as necessary in addition to the above-described compatibilizer and foaming agent. , Light stabilizers, colorants such as pigments and dyes, fillers, antistatic agents, lubricants, nucleating agents, flame retardants, antiblocking agents, dehydrating agents, light scattering agents for translucency, gloss adjusting agents, etc. Can also be added.
[0039]
Among these additives, hindered phenols, sulfurs, phosphoruss, etc. as heat stabilizers, stearic acid metal salts, hydrotalcite, etc. as acid neutralizers, benzotriazoles, benzoates as ultraviolet absorbers, etc. Benzophenone, triazine, etc., and light stabilizers include hindered amines.
[0040]
Examples of flame retardants include halogen flame retardants, phosphorus flame retardants, and chlorine flame retardants. Fillers include calcium carbonate, silica, titanium oxide, barium sulfate, zinc oxide, alumina, talc, mica, magnesium silicate, and titanium. Examples include potassium acid, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, iron oxide, carbon black, and metal powder.
[0041]
As lubricants, hydrocarbon lubricants, fatty acids, higher alcohols, fatty acid amides, metal soaps, esters, fluorines, etc. As nucleating agents, carboxylate metal salts, sorbitol, phosphate ester metal salts, etc. Examples of pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, mica, and other pearl pigments. Generally used in combination.
[0042]
In the present invention, the kneading of the thermoplastic resin 13, the wood filler 14, the compatibilizer, the foaming agent and other additives constituting the wood resin composition 15 is not particularly limited, but it is kneaded by a Banbury mixer. In general, a pelletizing method using a pelletizer, a mixing and pelletizing method using a twin-screw extrusion kneader, and the like are generally used. Moreover, since the wood filler 14 causes foaming during pelletization when the moisture content is large, it is desirable to suppress the moisture content to 8% or less in advance with a dryer or a hopper dryer before kneading.
[0043]
The woody resin foam molded body 1 of the present invention may be used as it is as a structural material for construction or furniture, or may be used as it is or with decorative processing such as embossing or pattern printing on the surface, for construction or furniture. Sometimes used as a cosmetic material. As the decorative process in the latter, it is generally difficult to directly print a pattern on the surface of the wood resin foam molded body 1, so a decorative process such as a pattern print is applied to a support such as a thermoplastic resin film prepared in advance. Most preferably, the applied decorative sheet 2 is laminated on at least a part of the surface of the wood resin foam molded body 1 (a part requiring decoration processing).
[0044]
At that time, when a decorative sheet 2 mainly composed of a polyolefin resin, which is a thermoplastic resin similar to the polyolefin resin 13 contained in the wood resin foam molded article 1, is used, the decorative material after use is recycled. In addition, the wood resin foam molded body 1 and the decorative sheet 2 can be used again as a material of the wood resin foam molded body 1 without separation, and no molding failure occurs during molding during recycling. Recycled products have the advantage that the wood texture is not impaired and the strength is not reduced.
[0045]
Specific examples of the polyolefin resin constituting the decorative sheet 2 include polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α olefin copolymer, propylene- Among various polyolefin resins such as α-olefin copolymers, ethylene-ethyl acrylate copolymers, acid-modified ones for the purpose of improving adhesion, ionomers, mixtures thereof, copolymers, etc. It is possible to select appropriately, and it is also possible to use a multi-layer laminate composed of the same or different types of polyolefin resins selected from these.
[0046]
The important points about the decorative sheet 2 to be laminated are that, as described above, the use of a thermoplastic resin similar to the thermoplastic resin 13 contained mainly in the wood resin foam molded article 1, and the grain, stone, texture, abstract Since the decorative process is performed by pattern printing or embossing of a design such as a pattern, there is no restriction on the configuration of the decorative sheet itself.
[0047]
This decorative sheet 2 is, for example, a single-layer decorative sheet obtained by printing on a colored sheet, or a sheet obtained by printing a colored sheet on a transparent sheet bonded by a dry lamination method, an extrusion lamination method, a thermal lamination method, or the like. It can be appropriately selected depending on the application from a single-layer decorative sheet, a back-printed single-layer decorative sheet printed on the back surface of a transparent sheet, and the like.
[0048]
At this time, if the decorative sheet 2 has sufficient concealment, a stable design reproduction can be achieved. Conversely, if the decorative sheet has transparency, it is possible to express the design using the wood texture of the wood resin foam molded body 1. Become.
[0049]
Ink used for printing pattern, pattern, coloring, etc. of decorative sheet 2 such as grain pattern, nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, etc. alone Or what is necessary is just to select suitably from each modified | denatured substance. These may be any of aqueous, solvent-based and emulsion types, and can be arbitrarily selected from a one-component type or a two-component type using a curing agent. Further, the ink can be cured by irradiation with ultraviolet rays or electron beams.
[0050]
Among them, the most general method is a method of curing with an isocyanate using a urethane-based ink. In addition to these binders, colorants such as pigments and dyes, extender pigments, solvents, and various additives contained in ordinary inks are added. Particularly frequently used pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, mica and other pearl pigments.
[0051]
In any decorative sheet 2, a primer coat for bonding to the wood resin foam molded body 1, a top coat for surface protection and gloss adjustment, a conduit expression by an embossing method or a gloss mat method, etc. It may be given. Moreover, the additive used for the thermoplastic resin layer in the decorative sheet 2 can be used as appropriate as in the wood resin foam molded article 1.
[0052]
The thickness of the decorative sheet 2 is not particularly limited, but is usually in the range of about 0.05 to 0.3 mm. The lamination method of the decorative sheet 2 and the wood resin foam molded body 1 is not particularly limited. For example, a dry lamination method or a wet lamination method using an adhesive, a thermal lamination method using or not using an adhesive, or an ultrasonic fusion. Conventionally known methods such as a method for forming and laminating a decorative sheet 2 in a cooling sizing mold at the same time as foam extrusion molding of a wood resin foam molded body 1 and a method of high frequency fusion bonding, and a pasting method may be arbitrarily used. it can.
[0053]
In many cases, the side surface of the woody resin foam molded article 1 as a base material of the decorative material of the present invention is provided with a fitting structure such as male and female for connecting the decorative materials to each other. In this case, in order to ensure the strength and dimensional accuracy of the fitting structure portion, it is desirable that the fitting structure portion is non-foamed or in a low foamed state with a foaming ratio of 1.5 times or less. According to the Celca method described above, the fitting structure portion is a thin portion with an intricate structure, so the contact area with the cooling sizing mold increases, and a non-foamed or low-foamed fitting structure portion is easily formed. There are advantages that can be done. Further, when the fitting structure portion is provided in this way, it is continuous from the decorative surface over the surface of the portion of the wood resin foam molded body 1 that can be seen from the decorative surface (surface exposed to the outside) side at least in the connected state. Then, it is desirable to laminate the decorative sheet 2.
[0054]
When recycling the decorative material of the present invention, the decorative sheet 2 laminated on the surface is crushed as it is without being peeled off, and a wooden filler, polyolefin resin, various additives, etc. are added as necessary. Then, it can be pelletized again and reused as a molding material for the wood resin foam molded body 1. Also in this case, the method for kneading the crushed material, the pelletizing method, the forming method, etc. is not particularly limited. Further, instead of re-pelletizing, the crushed material is directly put into a molding machine as a molding material for the wood resin foam molded body 1, or when the wood resin foam molded body 1 is molded, the crushed material and the wooden filler or thermoplastic resin are used. Of course, it is also possible to put in the molding machine at the same time, and molding while kneading in the molding machine.
[0055]
【Example】
Specific examples of the present invention will be described below.
[0056]
Example 1
A wood resin composition comprising the following composition is molded into a rectangular cross-section having an average foaming ratio of 1.4 times, a thickness of 6 mm and a width of 300 mm by a Celca method using a single screw extruder, and the wood resin foam molded article of the present invention. As a result of molding, a good molded body could be obtained.
[0057]

[0058]
After the corona discharge treatment is performed on the surface of the wood resin foam molded body, a polypropylene resin decorative sheet having a wood grain print is laminated on the upper surface and both side surfaces by a lapping method, and the decorative material of the present invention Was made. This decorative material could be suitably used as a flooring material.
[0059]
Comparative Example 1
In the said Example 1, the mixing | blending of the wood resin composition was changed as follows, and others made the wood resin foam molded object on the same conditions.
[0060]

[0061]
Comparative Example 2
In the said Example 1, the mixing | blending of the wood resin composition was changed as follows, and others made the wood resin foam molded object on the same conditions.
[0062]

[0063]
Comparative Example 3
In the said Example 1, the mixing | blending of the wood resin composition was changed as follows, and others made the wood resin foam molded object on the same conditions.
[0064]

[0065]
Evaluation
About the said Example 1 and Comparative Examples 1-3, when the condition at the time of shaping | molding (take-off property, resin adhesion to a screw) and the finished product (thickness nonuniformity, surface property) were evaluated, it was as the following table. It was. However, in Comparative Example 1, continuous foam was generated and the surface was uneven, and in Comparative Examples 2 and 3, the woody resin composition was stuck to the screw of the molding machine and could not be molded.
[0066]

[0067]
【The invention's effect】
As described above in detail, the wood resin foam molded article and the decorative material of the present invention are foam molded articles mainly composed of a polyolefin resin and a wood filler, and thus have an external feeling and a tactile sensation similar to wood. In addition to the above-mentioned polyolefin resin and wood-based filler, a predetermined amount of an acrylic-modified polytetrafluoroethylene-based compatibilizer and a maleic acid-modified polypropylene-based compatibilizer is included. By using the blended wood resin composition, the binding force between the polyolefin resin and the wood filler is strong, it is possible to foam uniformly without generating open cells, and the melt tension is high and foaming is easy. Foam moldability, such as good dispersibility and kneadability, easy crystallization of polyolefin resin, and difficult adhesion to mechanical parts such as metal screws Because it is excellent, the wood-based filler is uniformly dispersed while being well-bonded with the polyolefin-based resin, and is uniformly foamed, and has excellent mechanical strength, surface properties, thickness accuracy, etc., and poor molding It has a remarkable practical advantage that it is a wood resin foam molded body that can be produced stably and efficiently without causing an accident.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an embodiment of a woody resin foam molded article and a decorative material of the present invention.
[Explanation of symbols]
1 Wood resin foam molding
11 core
12 Surface layer
13 Polyolefin resin
14 Wood filler
15 Woody resin composition
16 bubbles
2 Makeup sheet

Claims (5)

In a wood resin foam molded article formed by foaming a wood resin composition mainly composed of a polyolefin resin and a wood filler, the wood resin composition comprises 80 to 15% by weight of a polyolefin resin and a wood filler. The main component is 20 to 85% by weight, and 0.5 to 10 parts by weight of an acrylic-modified polytetrafluoroethylene-based compatibilizing agent and 0.5 to 0.5 parts by weight of a maleic acid-modified polypropylene-based compatibilizing agent per 100 parts by weight of the wooden filler. A wood resin foamed molded article containing 5 parts by weight. The woody resin foam molded article according to claim 1, wherein the maleic acid-modified polypropylene compatibilizer has a maleic acid modification rate of 4% or more. 3. The woody resin foam molding according to claim 1, which has a multilayer structure in which a non-foamed or low foaming ratio surface layer part is laminated on at least a part of a surface of a core part having a high foaming ratio. body. 4. The woody resin foam molded article according to claim 3, which is molded by a Celca method. A decorative material comprising a decorative sheet mainly comprising a polyolefin-based resin laminated on at least a part of the surface of the woody resin foam molded article according to any one of claims 1 to 4.

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