JP2008247973A - Foamed molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed molding being excellent in woody quality and recyclability and having a thermal conductivity moderate enough to eliminate problems such as raise even when used for a flooring material for floor heating and to provide a flooring material using the same. <P>SOLUTION: Provided are a foamed molding which is a foamed molding 1 comprising a woody resin composition containing at least a thermoplastic resin 3, a woody filler 4, and a negative thermal expansion material 2, wherein the negative thermal expansion material 2 is a crystal with a reverse perovskite structure and a flooring material 7 provided with the foamed molding 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a foam molded article and a flooring using the same. The foamed molded product of the present invention and the floor material using the same are suitably used particularly for indoor floor surfaces in buildings such as detached houses, condominiums, apartments, recreational facilities, office buildings, and stores.

  Currently, wooden flooring materials are the most prevalent as floor materials for indoor floors in buildings such as detached houses. This wood-based flooring material is a natural wood veneer with a thickness of several hundreds μm to several mm on a wooden substrate such as a solid plate of natural wood with a thickness of about 5 to 15 mm or a laminated plywood with a thickness of about 5 to 15 mm. It is the thing which stuck, or those painted goods.

  These wood-based flooring materials using natural wood have been widely accepted by consumers since the design of the surface of the wood is the most natural, friendly and beautiful wood grain.

  However, these wooden flooring materials are easily discolored when exposed to sunlight, and are prone to swelling, cracking, warping, corrosion, peeling of the veneer, etc. when wet, especially in bathroom changing rooms and bathrooms, It has been pointed out that there are problems with use in areas such as kitchens, or that the quality, price, and supply volume of the color tone and grain shape are unstable because it is a natural material. ing.

  On the other hand, in recent years, as social interest in global environmental protection issues has increased, mass consumption of natural wood that leads to environmental destruction has become a sight, and in the field of building materials such as flooring, the use of recycled resources The approach to has come to be required.

  However, it is extremely difficult to recycle wood flooring materials as flooring materials, both technically and economically, and only to the extent that they can be crushed and recycled as particleboard raw materials. is there. In addition, such recycling use also has excessive inventory because application development corresponding to the rapid increase in supply in recent years does not proceed, and recycling use is in a deadlock situation, most of which is final disposal by landfill or incineration The current situation is.

  Under such circumstances, there is a strong social demand for the development of a flooring material that can be reused as a raw material for the same kind of flooring material after being used as a flooring material and that is suitable for recycling. In order to meet these demands, the present applicant has already mainly used a thermoplastic resin similar to the thermoplastic resin constituting the wooden resin molded body on the surface of the wooden resin molded body containing the thermoplastic resin and the wooden filler. We propose a flooring made of laminated decorative sheets.

  Since this flooring is mainly composed of thermoplastic resin, it has excellent water resistance and weather resistance, is stable in terms of physical properties and design, and can be supplied in large quantities at low cost. Workability such as hammering is equivalent to wood flooring. And after use, it also has excellent recyclability that it can be pulverized as it is and reused as a molding material for the wood resin molding.

Furthermore, a flooring material using a wood resin foam molded body made of a foamed wood resin molded body for the purpose of improving heat insulation that gives a warm touch similar to natural wood and elasticity that gives a pleasant walking feeling. Has also been proposed.

However, the wood resin foamed molded product has a problem that the molded product protrudes in summer or when floor heating is used. This is because the thermoplastic resin, which is the main component, increases in volume when the temperature rises (the coefficient of linear expansion is large). Therefore, a molded body in which expansion is suppressed by mixing a liquid crystal resin, which is a material having a negative volumetric expansion (negative linear expansion coefficient, negative expansion) material, with a thermoplastic resin is proposed (Patent Document). However, since it is made of resin, the thermal conductivity is low and the heating efficiency is poor.
JP 2006-168120 A

  The present invention has been made in order to solve the above-described problems, and is a foam molded article having excellent wood texture and recyclability, no problem of being pushed up even when used for heating, and good thermal conductivity. And it aims at providing the flooring using the same.

The invention according to claim 1 is a foamed molded article made of a wood-based resin composition containing at least a thermoplastic resin, a wood-based filler, and a negative expansion material, wherein the negative expansion material has a reverse perovskite structure. It is a foaming molding characterized by being a crystal body which has.
The invention according to claim 2 is the foam molded article according to claim 1, wherein the crystal body having the inverted perovskite structure is a nitride.
The invention according to claim 3 is the foamed molded article according to claim 1 or 2, characterized in that the crystal body having the inverted perovskite structure is manganese nitride.
The invention described in claim 4 is characterized in that the metal coordinated to the manganese nitride is one or more of copper, zinc, gallium, germanium, and manganese. This is a foam molded article.
Invention of Claim 5 is provided with the foaming molding in any one of Claims 1-4, It is a flooring characterized by the above-mentioned.

  Invention of Claim 1 is a foaming molding which consists of a wooden resin composition which contains a thermoplastic resin, a wooden filler, a foaming agent, and a negative expansion material at least, Comprising: The said negative expansion material is Since it is a foamed molded product characterized by being a crystal body having a reverse perovskite structure, it has excellent wood texture and recyclability, has no problems such as pushing up even when used for heating, and has the effect of good thermal conductivity Play. Also, the negative expansion material makes the foaming agent highly foamed at the time of molding, increasing the warm touch feeling similar to natural wood, the elasticity that gives a pleasant walking feeling, and the heat insulating property, thereby reducing the weight. Further, since the negative expansion material exhibits metallic properties, it has good thermal conductivity, and when used as a floor heating floor material, the room can be warmed with less energy than a conventional floor material. In addition, since the negative expansion material is a relatively inexpensive and environmentally friendly material, there is an advantage that disposal after use becomes easy.

  The invention according to claim 2 is the foam molded article according to claim 1, wherein the crystal body having the inverted perovskite structure is a nitride. Since such a crystal is several times larger than the negative expansion coefficient of a conventional oxide material, it is more effective when used with a thermoplastic resin having a large linear expansion coefficient. In addition, oxide-based negative expansion materials such as zirconium tungstate and silicon oxide were all insulators. However, nitrides having an inverted perovskite structure exhibit metallic properties and thus are electrically conductive. High in thermal conductivity. Therefore, when used as a flooring material for summer or floor heating, the room can be warmed with less energy than a conventional flooring material.

  The invention according to claim 3 is the foamed molded article according to claim 1 or 2, characterized in that the crystal body having the inverted perovskite structure is manganese nitride. Manganese nitrides are isotropically negatively expanded, so the operation is stable, and even if the cycle of temperature rise and temperature fall is repeated, it retains the property of negative expansion permanently. Ideal for.

  The invention described in claim 4 is characterized in that the metal coordinated to the manganese nitride is one or more of copper, zinc, gallium, germanium, and manganese. This is a foam molded article. Since the magnitude of negative expansion can be controlled by changing the type and ratio of constituent elements such as copper, zinc, gallium, germanium, and manganese, it can be used in a wide range of applications. Further, since the metal is a relatively inexpensive and environmentally friendly material, disposal after use is easy.

  Since the invention according to claim 5 is a flooring material comprising the foamed molded article according to any one of claims 1 to 4, it is excellent in wood texture and recyclability and is used for heating. However, there is no problem such as pushing up, and there is an effect that the thermal conductivity is good.

Hereinafter, the present invention will be described in more detail.
FIG. 1 is a cross-sectional view of an embodiment of a flooring material using the foamed molded product of the present invention. The foamed molded product 1 of the present invention comprises at least a negative expansion material 2, a thermoplastic resin 3, a wood-based filler 4, and bubbles 5 formed by a foaming agent. A decorative sheet 6 is laminated on one surface of the foam molded body 1 to form a flooring 7.

As the negative expansion material 2 in the present invention, a crystal having an inverted perovskite structure is used. The perovskite structure is a structure in which the metal is located in the center and the nonmetal is located around it, while the reverse perovskite structure is reversed, the nonmetal is located in the center and the metal is located around it . FIG. 2 shows a schematic diagram of the inverted perovskite structure of manganese nitride (Mn3 (X) N). The magnitude of negative expansion can be controlled by changing the type and ratio of constituent elements such as copper, zinc, gallium, germanium, and manganese coordinated with X, and the volume is continuously reduced in the range of 0 ° C to 100 ° C. It is possible. More preferably, the germanium is coordinated from 20% to 70%. The linear expansion coefficient is preferably −3 × 10 ⁻³ to 3 × 10 ⁻³ , and the linear expansion coefficient (inclination of the linear expansion coefficient) is in the range of −1 × 10 ⁻⁷ / ° C. to −5 × 10 ⁻⁵ / ° C. preferable. As a method for producing the crystal, a known method such as firing is used.
The negative expansion material 2 is preferably added in an amount of 1 to 20% by weight in the foamed molded body.

Examples of the thermoplastic resin 3 include polyolefin-based polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer. Appropriate ones can be selected from polymers, ethylene-ethyl acrylate copolymers, those obtained by acid modification for the purpose of improving adhesiveness, ionomers, and the like. Specifically, one or more of these may be selected and used.

  Among these, polypropylene resins such as homopolypropylene, random polypropylene, block polypropylene, and propylene-α-olefin copolymer are most suitable in consideration of the rigidity, surface hardness, dimensional stability, etc. required for flooring materials. .

  On the other hand, as the wood-based filler 4, for example, a material obtained by breaking a wood with a cutter mill or the like and pulverizing the wood with a ball mill or an impeller mill to obtain a fine powder (wood powder) may be used.

  The average particle diameter of the wood filler 4 is preferably about 1 to 200 μm, and more preferably 10 to 150 μm. When the average particle size is less than 1 μm, it is difficult to handle, and when the amount of the wood filler 4 having such a particle size is large and the dispersion in the thermoplastic resin is poor, Strength will be reduced. Moreover, when larger than 200 micrometers, the homogeneity of a foaming molding, flatness, and mechanical strength will fall.

  Moreover, it is preferable that the compounding quantity of the wood type filler 4 shall be in the range from 10 weight part to 300 weight part with respect to 100 weight part of the thermoplastic resin 3. FIG. In order to further improve the moldability and homogeneity, the wood filler is kneaded in an amount of 20 to 200 parts by weight, more preferably 30 to 150 parts by weight with respect to 100 parts by weight of the thermoplastic resin 3. Good. If the amount of the wood filler 4 is too large, the flexural modulus of the flooring will increase and the flexibility will be lost, so the workability will be deteriorated (especially at the time of construction at the corner or when replacing one piece, It becomes difficult to bend the flooring and install it.) It becomes easy to break when bent. On the other hand, if the amount is too small, the coefficient of linear expansion increases and the dimensional stability decreases, so that a change in temperature tends to cause gaps in the butt portion of the flooring or floating due to the pushing-up.

In addition to the negative expansion material 2, the thermoplastic resin 3, and the wood filler 4, a foaming agent is added to foam in the molding process and form bubbles 5.
There are various methods of foaming at the time of molding, but generally, chemical foaming that generates gas by thermal decomposition or chemical reaction and physical foaming that heats and vaporizes low boiling point liquids are adopted. it can. Examples of foaming agents used for these foams include inorganic sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals, azide compounds as chemical foaming agents, and organic foams. Examples of the agent include azo series, nitroso series, and hydrazide series.

  When foaming is desired at a high foaming ratio exceeding 2 times, physical foaming is mainly used. At this time, it is preferable to mainly use carbon dioxide gas or aliphatic hydrocarbon as the blowing agent. Further, a chemical foaming agent may be used in combination in order to adjust the cell shape of the foam during physical foaming.

  The kneading of each component such as the negative expansion material 2, the thermoplastic resin 3, the wood filler 4, the foaming agent and other additives is not particularly limited, but is kneaded with a Banbury mixer and pelletized with a pelletizer. Specific examples include a method of forming a mixture and a method of mixing and pelletizing with a twin-screw extrusion kneader. Further, since the wood filler 4 causes foaming during pelletization when the moisture content is large, it is desirable to keep the moisture content to 8% or less in advance with a dryer or hopper dryer before kneading.

  In the present invention, the molding and foaming method of the foam molded body 1 is not particularly limited, and conventionally known methods such as an extrusion molding method, a calender molding method, an injection molding method, and a cast molding method can be arbitrarily employed. In addition, in the case of a multi-layer laminate having different foaming ratios, a plurality of types of compositions with different blending amounts of the foaming agent are separately molded by an extrusion method, an injection molding method, or the like, and then bonded together. And a sequential extrusion method or a co-extrusion method using a plurality of types of compositions, and a Celca molding method capable of forming a single type of composition continuously and stably in a single step. .

  In the present invention, the composition used for molding the foamed molded article 1 includes a heat stabilizer, a lubricant, a nucleating agent, a pigment, an acid neutralizer, an ultraviolet absorber, an antiblocking agent, a dehydrating agent, if necessary. It is also possible to add a light scattering agent, a gloss adjusting agent, etc. for making translucent.

  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.

  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, isoindolinone, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, mica, and other pearl pigments. Generally, it is used in combination.

  As mentioned above, although the structure of the foaming molding 1 and its manufacturing method were described, the flooring 7 of this invention is because the decorative sheet 6 which has a base material sheet is laminated | stacked on one surface of the foaming molding 1 mentioned above. can get.

Specific examples of the base sheet include polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, propylene-α-olefin. A plastic sheet made of a copolymer, an ethylene-ethyl acrylate copolymer, an acid-modified product of these for the purpose of improving adhesiveness, an ionomer, a mixture thereof, a copolymer, or the like can be used.
More preferably, when the constituent material of the base sheet is the same as that of the main component of the foam molded article 1, a large change in physical properties occurs even when this ground product is mixed when the used flooring is collected and recycled. I will not let you.

  Further, in the flooring of the present invention, a foamed layer mainly composed of a thermoplastic resin similar to the thermoplastic resin 3 constituting the foamed molded body 1 is formed on the back surface of the foamed molded body 1 having the above-described configuration (see FIG. (Not shown) may be laminated. By laminating such a foam layer on the back side of the flooring, it absorbs unevenness on the bottom surface of the floor to prevent rattling, or absorbs the impact sound and walking sound of articles on the floor surface. Effects such as preventing noise can be exhibited.

For example, the foamed layer is vaporized by applying heat to a chemical foaming agent or a low-boiling liquid that generates gas by the thermal decomposition or chemical reaction to the thermoplastic resin similar to the thermoplastic resin 3 used for the foamed molded body 1. It can be formed by sticking a foam molded body foam-molded into a sheet shape with a resin composition containing one of the physical foaming agents to be bonded to the back surface of the foam molded body 1 on which the decorative sheet 6 is not laminated. .
The linear expansion coefficient of the molded product of the present invention is preferably 5 × 10 ⁻⁵ / ° C. or less, and more preferably in the range of 1 × 10 ⁻⁶ / ° C. to 5 × 10 ⁻⁵ / ° C.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not limited to the following example.

Example 1
As a thermoplastic resin, a homopolypropylene resin obtained by adding 20% by weight of a maleic acid-modified homopolypropylene resin to a homopolypropylene resin was used. The powder was pulverized by a ball mill to an average particle size of 100 μm, 100 parts by weight of this, 1 part by weight of a calcium stearate-based lubricant, and manganese nitride Mn ₃ (Ga 10 parts by weight of _0.5 Ge _0.4 Mn _0.1 ) N was mixed by a twin-screw extrusion kneader and pelletized to prepare a composition. 3 parts by weight of triallyl isocyanurate and baking soda-citric acid foaming agent are added to 100 parts by weight of the wood resin composition, and the foaming ratio is 2.5 times by a Celca process using a single screw extruder. The molded product was formed into a rectangular shape with a length of 6 mm and a width of 300 mm, and the surface was further subjected to corona discharge treatment to produce a foamed molded product.

  On the other hand, on a colored polypropylene sheet having a thickness of 100 μm formed with random polypropylene containing a pigment of iron oxide and titanium oxide, wood printing is performed with urethane ink, and a homopolypropylene resin sheet (thickness 100 μm is obtained by extrusion lamination method). ) Was simultaneously embossed to obtain a laminated sheet. Next, a primer coat was applied to the back surface of the laminated sheet, and a top coat was applied to the surface (the surface of the homopolypropylene resin sheet) to prepare a polypropylene resin decorative sheet.

  Subsequently, the decorative sheet was continuously bonded to the surface of the foamed molded article by a lapping method, and then cut at 1000 mm intervals in the length direction to obtain the flooring of the present invention according to Example 1. It was.

Comparative Example 1
In Example 1, Example 1 was repeated except that a crystal having an inverted perovskite structure was not used and 10 parts by weight of talc was used instead, thereby producing a flooring material.

<Evaluation>
The linear expansion coefficient of the foam molded article according to Example 1 was 1 × 10 ⁻⁵ / ° C., and the linear expansion coefficient of the wood resin foam molded article according to Comparative Example 1 was 6 × 10 ⁻⁵ / ° C.
Further, the floor material according to Comparative Example 1 was pushed up when used for summer and floor heating, but the floor material according to Example 1 was not pushed up. Moreover, the room could be warmed with half of the energy used for the flooring according to Comparative Example 1.

  The foamed molded product of the present invention and the floor material using the same are suitably used particularly for indoor floor surfaces in buildings such as detached houses, condominiums, apartments, recreational facilities, office buildings, and stores.

It is sectional drawing of one Embodiment of the flooring using the foaming molding of this invention. It is a schematic diagram of the reverse perovskite structure of the present invention.

Explanation of symbols

1 .. Foam molded body 2. Negative expansion material 3. Thermoplastic resin 4. Wood filler 5. Bubble 6. Cosmetic sheet 7. Floor material

Claims (5)

  A foam molded article comprising a wood-based resin composition containing at least a thermoplastic resin, a wood-based filler, and a negative expansion material, wherein the negative expansion material is a crystal body having a reverse perovskite structure. Foam molded body.   The foamed molded product according to claim 1, wherein the crystal having the inverted perovskite structure is a nitride.   The foamed molded article according to claim 1 or 2, wherein the crystal having the inverted perovskite structure is manganese nitride.   The foam molded article according to claim 3, wherein the metal coordinated to the manganese nitride is one or more of copper, zinc, gallium, germanium, and manganese.   A flooring material comprising the foamed molded product according to any one of claims 1 to 4.

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