JP6030533B2 - Low thermal conductive molded body and heat shielding resin laminate - Google Patents

Description

  The present invention relates to a woody material suitable for a building material, a low thermal conductivity molded body having a low thermal conductivity, and a heat shielding resin laminate.

Wood-like resin moldings containing wood powder are widely used as flooring materials for house verandas, balconies, fence materials, handrail materials, bench materials, and the like.
Since the flooring etc. are laid and used outdoors, when heated in the summer with strong sunlight, the surface temperature of the synthetic resin is 50 ° C without being radiated quickly due to the low thermal conductivity of the synthetic resin. May reach around 60 ° C. When walking with bare feet or touching with bare hands on the floor material in such a heat storage state, there was a risk of not only being extremely hot and difficult but also causing burns. In addition, since bench materials and the like are installed and used outdoors, there are similar problems.

Various proposals have been made as methods for solving the above problems. For example, a method of forming a synthetic resin layer containing a heat-shielding pigment on the surface of a flooring (Patent Document 1), a method of forming a synthetic resin layer containing a hollow filler such as a silica balloon or a glass balloon on the surface of a flooring (Patent Document 2).
The inventors of the present application made additional trials with respect to these methods. As for the former, the effect of reducing the heat storage was still about insufficient at about 5 ° C. in terms of temperature. In the latter case, in the case of a thin molded body, the contained hollow filler was cracked, and a predetermined heat lowering effect was not obtained. Further, the method using a thermally expandable balloon in which liquid hydrocarbons are encapsulated in a thermoplastic resin shell and microencapsulated has a certain effect, but on the other hand, the hardness of the material is reduced and it becomes easy to wear. That is, a phenomenon in which durability is lowered occurred.

JP 2011-252366 A JP 2009-133304 A

The inventors of the present application have conducted intensive research on a material in which a foam layer is formed on the surface of a resin base material. As a result, the surface layer portion of the foam resin body (foam layer) is continuous with the foam resin body base and has a higher density. By providing a skin layer, the thermal conductivity is lowered, and even if the limb comes in contact with the heat-stored foamed resin body surface, it becomes a material that does not easily transfer heat to the limb, and the material has high hardness and high wear resistance As a result, the present invention has been completed.
Furthermore, it has been found that a laminated resin body obtained by laminating the foamed resin body on a resin base material is suitable for a building material such as a flooring material that requires rigidity and low thermal conductivity.

According to the present invention, an outdoor flooring comprising a heat-shielding resin laminate in which a low thermal conductive molded body is laminated in a sheet form on a resin substrate,
The low thermal conductive molded body is
(A) Thermoplastic resin 50 to 95% by mass, (B) Wood powder 5 to 50% by mass [the sum of (A) and (B) is 100% by mass], and (C) Chemical foaming agent ( A) a thermoplastic resin and (B) a foamed resin body obtained by foaming and extruding a foamable composition containing 1 to 5 parts by mass with respect to 100 parts by mass of the total amount of wood flour. The (A) thermoplastic resin Is acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-styrene-acrylate resin (ASA resin), or a mixed resin thereof ,
In the surface layer portion of the foamed resin body, there is a skin layer continuous with the foamed resin body base, and the ratio of the thickness direction of the skin layer is 10 to 33% with respect to the thickness of the foamed resin body. density of a 0.50~0.90g / cm ^3, outdoor flooring density of the skin layer is characterized in that it is a 0.95~1.20g / cm ³ is provided.
In the invention of the outdoor flooring ,
(1) The average thickness of the skin layer is 0.3 to 1.0 mm. (2) The foaming ratio of the entire molded body is 1.1 to 2.0 times. (3) The thermal conductivity is 0. It is preferable that it is 3 to 0.15 W / Mk (4) The durometer hardness is 75 to 85 (5) It is preferable that the surface of the skin layer is uneven.

In the invention of the outdoor flooring,
(6) The resin base material is a hollow resin base material.
(7) The resin base material is a foamed resin base material.
(8) The thickness of the low thermal conductive molded body is 0.7 to 5.0 mm.
Is preferred.
According to the present invention, there is further provided a method for producing the outdoor flooring material, wherein foaming of the foamable composition and lamination molding on the resin substrate are performed by integral molding by coextrusion molding.

  The low thermal conductivity molded body provided by the present invention and the heat-shielding resin laminate in which the molded body is laminated on the surface have low conductivity to the surface of the stored heat. Can be effectively suppressed. Moreover, it has high hardness and high wear resistance, and when laminated on a resin base material, it is very useful as a building material such as a wood-like floor material, bench material, fence material, handrail material.

It is a schematic diagram of the SELKA process molding machine used by this invention. 2 is a SEM cross-sectional photograph of the heat-shielding resin laminate obtained in Example 1. 4 is a SEM cross-sectional photograph of a heat-shielding resin laminate obtained in Comparative Example 3. 6 is a SEM cross-sectional photograph of a heat-shielding resin laminate obtained in Comparative Example 4. 2 is a thermographic photograph before and after measurement of contact temperature sensation temperature in Example 1. FIG. It is a thermography photograph before and after measurement of contact temperature sensation temperature in Comparative Example 3. 1 is a cross-sectional view of a heat shielding resin laminate obtained in Example 1. FIG. It is sectional drawing of the heat insulation resin laminated body obtained in Example 10. FIG. 4 is a SEM cross-sectional photograph of a heat-shielding resin laminate obtained in Example 10.

The low thermal conductivity molded body of the present invention has a woody appearance including wood powder, and has low thermal conductivity, and suppresses the transfer of heat stored to the surface.
The low thermal conductive molded body is composed of a foamed resin body obtained by foam extrusion molding a foamable composition containing a specific amount of (A) a thermoplastic resin, (B) wood flour, and (C) a chemical foaming agent, And it has the characteristic that the skin layer continuously formed in the foamed resin body base part exists in the surface layer part of the said foamed resin body.

Specifically, the foamed resin body is composed of two parts, a foamed resin body base having a different density and a skin layer continuous therewith. The density of the foamed resin body base is 0.50 to 0.90 g / cm ³ . The density of the skin layer is 0.95 to 1.20 g / cm ³ , and the ratio in the thickness direction of the skin layer is 10 to 33% with respect to the thickness of the foamed resin body.
The density of the foamed resin body base needs to be 0.50 to 0.90 g / cm ³ from the viewpoint of thermal conductivity and mechanical strength. If it is less than 0.50 g / cm ³ , the rigidity and compressive strength are poor. When it exceeds 0.90 g / cm ³ , the decrease in thermal conductivity is impaired.
The density of the skin layer needs to be 0.95 to 1.20 g / cm ³ from the viewpoints of thermal conductivity, hardness, and wear. Similarly, the ratio in the thickness direction of the skin layer needs to be 10 to 33% with respect to the total thickness of the foamed resin body. When the density of the skin layer is less than 0.95 g / cm ³ and / or the thickness of the skin layer is less than 10%, the hardness and wear resistance are poor. When the density of the skin layer exceeds 1.20 g / cm ³ and / or the thickness of the skin layer exceeds 33%, the thermal conductivity to the surface does not decrease.

[(A) Thermoplastic resin]
The thermoplastic resin in this invention is not specifically limited, A well-known thermoplastic resin can be used. Specifically, polyolefin resin such as polyethylene and polypropylene (PP); polyamide resin; polyacetal resin; polyester resin such as polyethylene terephthalate and polybutylene terephthalate; fluororesin; polyphenylene sulfide resin; polystyrene, acrylonitrile-butadiene-styrene resin (ABS) Resin), acrylonitrile-ethylene-styrene resin (AES resin), styrene resin such as acrylonitrile-styrene-acrylate (ASA resin); acrylic resin such as polymethyl methacrylate; polycarbonate resin; polyurethane resin; polyvinyl chloride (PVC) Resin; Polyphenylene oxide resin; Commercial thermoplastic resin such as ethylene-vinyl acetate copolymer resin. Among these thermoplastic resins, ABS resin, ASA resin, or a mixed resin thereof is preferable from the viewpoint of impact resistance, rigidity, and weather resistance.
The blending amount of the thermoplastic resin is 50 to 95% by mass when the total amount with (B) wood flour described later is 100% by mass. If it is less than 50% by mass, the extrudability and mechanical strength are lowered, and if it exceeds 95% by mass, the wood texture due to wood powder is reduced. Moreover, if it exists in this range, foaming using a chemical foaming agent can be implemented effectively.

ABS resin is a copolymer of acrylonitrile, butadiene, and styrene, and is excellent in impact resistance, rigidity, tensile strength, and gloss. Its structure is a heterogeneous structure in which an elastic body such as polybutadiene is dispersed in an island shape in a matrix such as AS (acrylonitrile styrene) resin. To be precise, the three monomers of acrylonitrile, butadiene and styrene are co-polymerized. It is said that it is not a polymer. The content of acrylonitrile is generally 20 to 35%, but there are some that are about 40%. Butadiene is about 5 to 30%. There are also many improved ABS resins in which some of the above three components are replaced to improve properties such as gloss, fluidity, and heat resistance. These are commercially available as “Techno ABS” (Technopolymer), “UMGABS” (UMGABS), “Denka ABS” (Denki Kagaku Kogyo), etc., and can be selected and used according to the purpose. .
The ASA resin is a copolymer resin of acrylonitrile, styrene, and methyl acrylate. It is a resin that has an acrylic rubber component instead of the butadiene component of ABS resin and has excellent weather resistance while maintaining impact resistance, and is known per se. For example, it is commercially available as “Diarack” series from UMGABS.

[(B) Wood flour]
As the wood powder, a pulverized product of any wood such as conifer, hardwood or lauan wood is used. The particle size is not particularly limited, but generally a particle size of about 20 to 250 mesh is used. In addition to pulverized wood, crushed materials such as bark, grain husks, and waste wood can also be used.

[(C) Chemical foaming agent]
As a chemical foaming agent, the foaming agent conventionally used for manufacture of this kind of foamed resin molding can be used. Typical examples include inorganic foaming agents such as sodium bicarbonate, ammonium carbonate, and ammonium nitrite; N, N'-dimethyl-N, N'-dinitroso-terephthalamide, N, N'-dinitroso-pentamethylene, tetramine, etc. Nitroso compounds; azo compounds such as azodicarbonamide, azobisisobutyronitrile, azodiaminobenzene; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide; calcium azide, 4,4′-diphenyldisulfonyl azide, p -Azide compounds such as toluenesulfonyl azide. Of these, nitroso compounds, azo compounds and azide compounds are preferably used. A chemical foaming agent having a decomposition temperature compatible with the molding temperature of the thermoplastic resin to be used is selected from these chemical foaming agents.
The compounding quantity of the said chemical foaming agent is 1-5 mass parts with respect to 100 mass parts of total amounts of (A) thermoplastic resin and (B) wood flour. When the amount is less than 1 part by mass, effective foaming cannot be performed, and when it exceeds 5 parts by mass, various physical properties of the foamed resin body are deteriorated and the wood texture is also impaired.

  The chemical foaming agent can be used in combination with a foaming aid having functions such as promotion of decomposition and uniformization of bubbles as required. Examples of this type of foaming aid include inorganic foaming aids such as zinc acetate and talc, and organic foaming aids such as salicylic acid, phthalic acid, stearic acid, urea and derivatives thereof.

[(D) Other additives]
In the foamable composition used for foaming in the present invention, in addition to the foaming aid, a colorant for adjusting the color of the molded body, a lubricant for improving processability and moldability, a processing aid, In addition, other known additives such as light stabilizers, ultraviolet light inhibitors, antioxidants, antistatic agents, and fillers such as calcium carbonate and talc can be blended according to a formulation known per se.
In particular, polymer acrylic processing aids that contribute to the dispersion and growth of the foamed cells and that provide excellent surface formability are preferred additives. As such a polymer acrylic processing aid, an acrylic resin having an average molecular weight of 500,000 to 5,000,000, for example, polymethyl methacrylate (PMMA), or a part of structural units constituting PMMA, methyl acrylate, etc. And an acrylic copolymer substituted with a structural unit derived from another polymerizable monomer.

(Preparation of foamable composition)
The essential components of the present invention and other additives blended as necessary are mixed to prepare a foamed composition, and the foamed composition is subjected to foam extrusion molding to produce a foamed resin body.
The method for preparing the foamed composition is not particularly limited, and typically, a dry blending method using a blender, a hensil mixer or the like is employed. The order of blending is not particularly limited, and all components may be mixed at the same time, or may be mixed in multiple stages. For example, all components except chemical foaming agent are premixed first, then chemical foaming agent is mixed, or wood flour and chemical foaming agent, and any additives are premixed first and then thermoplastic resin is mixed. The method of doing is mentioned.

[Manufacture of low thermal conductive moldings]
Using the prepared foamable composition, foaming and melt extrusion are simultaneously performed to produce a foamed resin body. Typically, a method using an extruder is employed. That is, the foamable composition is supplied to a hopper of an extruder, mechanically melted and kneaded in the extruder, and extruded into the air through a die to form a foamed resin molded body. As the extruder, a known extruder with a single or twin screw is used, and kneading, extruding and foaming of each component are performed in one extruder, and the operation is simple and production is possible. It has the advantage of high performance.
The low thermal conductive molded body of the present invention is characterized in that the surface layer portion of the foamed resin body has a skin layer having the specific property. The foamed resin molded body having the skin layer is produced by rapidly cooling the surface of the foamed resin body obtained by the above production method immediately after molding. Specifically, the cooling method of the same shape installed in the die exit of an extruder, or the method of cooling with a cooling roll is mentioned. The former is a known method known as the Selca process, and FIG. 1 schematically shows a Selca process molding machine used in the present invention. The cooling temperature is appropriately selected according to the extrusion temperature of the thermoplastic resin to be used and the characteristics of the skin layer to be designed. Usually, the cooling temperature is a room temperature or a water temperature (5 to 20 ° C.) which is a cooling medium. Is set.

In the present invention, the density of the base of the foamed resin body needs to be 0.50 to 0.90 g / cm ³ . The density is basically controllable depending on the type and amount of the thermoplastic resin and chemical foaming agent to be used, but changes depending on the characteristics of the extruder, foaming extrusion molding temperature, molding time, etc. It is preferable to consider separately. When the density of the base is within the above range, the average diameter of the foamed cells in the base is 60 to 200 μm. The density of the base and the following skin layer was measured using “Electron Densitometer ED120-T” manufactured by Mirage Trading Co., Ltd.

In the present invention, the density of the skin layer is 0.95 to 1.20 g / cm ³ , and the ratio of the thickness direction of the skin layer is 10 to 33% with respect to the total thickness of the foamed resin body. It is necessary to be. The density and thickness of the skin layer can be basically controlled by the cooling temperature and cooling time (speed) of the cooling sizing and cooling roll. When the density of the skin layer is within the above range, the average diameter of the foam cells in the skin layer is 10 to 50 μm.

The low thermal conductivity molded body obtained in the present invention preferably has an expansion ratio of 1.1 to 2.0 times of the entire molded body, and a thermal conductivity of 0.3 to 0.15 W / Mk. The durometer hardness is 75 to 85. When the expansion ratio exceeds 2.0 times, the strength is greatly reduced.
Furthermore, in the low thermal conductive molded body, it is preferable that the surface (contact side) of the skin layer is provided with irregularities since the contact temperature feeling temperature of the limb is further lowered. The method for forming the surface irregularities is not particularly limited, and specifically, a chemical roughening method in which the surface treatment is performed with chemicals, a physical roughening method in which the surface treatment is performed with laser irradiation, a metal brush, sandpaper, etc. Examples thereof include a mechanical surface-roughening method for surface treatment and a method of forming irregularities on the surface of the skin layer of the mold in advance and forming it simultaneously with extrusion.

[Heat shielding resin laminate]
The low thermal conductivity molded article of the present invention has low thermal conductivity and is excellent in hardness and wear resistance. When building a building material such as a flooring using the low thermal conductive molded body, strength and rigidity are required. Therefore, a resin base material is used as a base, and the low thermal conductive molded body is formed on the base material. A (skin layer) is laminated to form a heat shielding resin laminate.
In FIG. 2, the cross-sectional SEM photograph of the heat-shielding resin laminated body obtained by this invention is shown.
As the resin used as the resin base material, the above-mentioned (A) thermoplastic resin is used without limitation. Among these thermoplastic resins, from the viewpoint of impact resistance, rigidity, flame retardancy, and weather resistance. ABS resin, ASA resin, vinyl chloride resin or a mixed resin thereof is preferable.

Further, it is particularly preferable that the resin base material has a wood texture, is self-extinguishing, and is incombustible as a building material. For this purpose, a flame retardant is usually blended in an amount of about 5 to 15% by mass in addition to the thermoplastic resin and wood powder.
As a flame retardant, it does not specifically limit but a well-known material can be used. Specifically, inorganic flame retardants such as antimony trioxide, antimony pentoxide, aluminum hydroxide, and magnesium hydroxide; phosphorus flame retardants such as triphenyl phosphate and aromatic condensed phosphate ester; tetrabromobisphenol A, deca Illustrative are halogenated organic flame retardants such as bromodiphenyl ether, brominated polyethylene and brominated polycarbonate. A halogen-based organic flame retardant or an inorganic flame retardant is preferably used.

When the use of the above flame retardant is a problem in terms of cost or environment, the resin base material is a self-extinguishing or non-flammable resin molded body that does not contain a flame retardant previously proposed by the present applicants. It is preferable (Japanese Patent Application No. 2012-37388).
Specifically, in order to express self-extinguishing properties, ABS resin 15 to 45% by mass, vinyl chloride resin 20 to 40% by mass, and wood flour 30 to 50% by mass [the total of the three components is 100% by mass A melt-molded product of a molding composition blended. In order to develop non-flammability, molding containing 15 to 30% by mass of ABS resin, 30 to 40% by mass of vinyl chloride resin, and 40 to 50% by mass of wood flour (the total of the three components is 100% by mass) A melt-molded product of the composition for use. In these molded articles, other additives (D) mentioned above can be blended without limitation.

The shape and internal structure of the underlying resin substrate are not particularly limited, and can be arbitrarily designed according to the purpose of use. For example, when the heat-insulating resin laminate of the present invention is used as a flooring, a hollow structure resin base material having a space inside is used as shown in FIG. 7 in order to increase rigidity and reduce weight. Is preferred.
When used as a bench material, it is preferable to use a foamed resin base material without making it hollow, as shown in FIG. 8, in order to ensure the appearance of the end portion and the locking force when screws or nails are used. The foaming method of the foamed resin base material is not particularly limited, and the above-described method is adopted without limitation. In the case of a foam resin base material, a co-extruder is used to produce a foam resin body for the skin layer, that is, the resin base material is foam-extruded at the same time as the foam layer foam extrusion, and foamed onto the foam resin base material. A method of laminating and molding a resin body (skin layer) is suitably employed. The formation of the skin layer after coextrusion is as described above.

[Production method of heat shielding resin laminate]
Although the manufacturing method of a heat-shielding resin laminate is not particularly limited, a coextrusion molding method capable of simultaneously performing foaming and lamination molding on a resin substrate is preferable because the operation is simple. Specifically, the first extruder corresponding to the resin substrate and the second extruder corresponding to the foamed resin body are used, and the composition for molding the substrate is melt-kneaded in the first extruder. Then, the foamable composition is melt-kneaded in a second extruder. In the foam extrusion lamination molding, each component is dry blended and supplied to the hopper of each extruder. As the extruder, a known extruder having a single-screw or a twin-screw is used. The resin stream of the resin base material from the first extruder and the resin stream of the foamed resin body from the second extruder are merged in a multilayer multiple die and extruded into the air in a laminated state. Thereafter, the surface on the foamed resin body side is cooled by the method described above to form a skin layer, and a heat shielding resin laminate having a layer of a low thermal conductivity molded body is obtained.

  Since the low thermal conductive molded body and the thermal barrier resin laminate of the present invention have a woody appearance, low thermal conductivity, low contact temperature, and excellent hardness and wear resistance, It can be widely used for flooring materials, pipe materials, fence materials, handrail materials, siding materials, balcony materials, louver materials and bench materials for terraces.

The invention is further illustrated in the following examples. The following examples are illustrative and the invention is not limited in any way. In addition, not all combinations of features described in the embodiments are essential to the solution means of the present invention.
Various components and abbreviations used in the following examples and comparative examples are as follows.
(A) Thermoplastic resin A-1: ASA resin Diamond rack E610 (manufactured by UMG ABS)
A-2: ABS resin Clarastic SR (manufactured by Japan A & L)
A-3: Vinyl chloride resin TH1000 (manufactured by Taiyo PVC Co.), average polymerization degree 1000
A-4: Polypropylene resin E701G (manufactured by Prime Polymer), MFR = 0.5
(B) Wood flour B-1: Wood flour having an average particle size of 50 μm (C) Chemical foaming agent C-1: Mixture of 50% by weight of azodicarbonamide and 50% by weight of sodium bicarbonate (D) Other additives D -1: Kane Ace PA20 (acrylic processing aid; manufactured by Kaneka)
D-2: Thermal expansion balloon expand cell 930MB (Nippon Philite)
D-3: Hollow glass beads Glass Bubbles S60HS (manufactured by Sumitomo 3M)

Measurement of density, thermal conductivity, contact temperature temperature, hardness, average foamed cell diameter, foaming magnification, abrasion resistance test, and surface temperature drop in Examples and Comparative Examples, and foaming state of each part of the foamed resin body Observation was performed as follows.
[Density]: Test method; JIS K7112, Submerged replacement method From each laminate, a piece of 30 mm length × 30 mm width was cut out, and then the resin substrate part was cut off from the laminate piece to remove the foamed resin body part. The test piece was taken out. Each density of the foamed resin base and the skin layer was measured using an electronic specific gravity type ED120-T (manufactured by Mirage Trading Co., Ltd.).
The density of the skin layer was calculated by the following method. The density of the foamed resin body and the density of only the base of the foamed resin body obtained by removing the skin layer by cutting are measured. On the other hand, the weight of the foamed resin body and the weight of only the foamed resin body base excluding the skin layer are measured. Using these values, the density of the skin layer was calculated.
[Thermal conductivity]: Test method; JIS A1412-2 Measurement method of thermal resistance and thermal conductivity of thermal insulation material Part 2: Conforms to the heat flow meter method (HFM method) Obtained in each example and comparative example, A laminate of length 300 mm × width 250 mm × thickness 30 mm was used as a test piece. The thermal conductivity in the stacking (thickness) direction of the test piece was measured using a rapid thermal conductivity meter QTM-D3 (manufactured by Kyoto Electronics Co., Ltd.).
[Contact temperature sense temperature]
A laminate having a length of 300 mm, a width of 250 mm, and a thickness of 30 mm obtained in each example and comparative example was used as a test piece.
In order to make the conditions the same, the test piece of Comparative Example 1 and the test piece of Example were placed on the foamed resin body side as an upper surface and left outdoors at a temperature of 34 ° C. for 2 hours, and the surface temperature of both test pieces was set to 70 ° C. (Measured with a thermography device below). At the same time, the left and right palms were placed on each test piece for 15 seconds to contact. After 15 seconds, each palm was immediately returned and the surface temperature at the center of each palm was measured simultaneously with a thermography apparatus Thermoshot F30 (Nippon Avionics).
[Hardness]: Test method; JIS A7215, 1986
From each laminate, a test piece having a length of 50 mm, a width of 50 mm, and a thickness of 5 mm was cut out and used as a test piece. The test piece was placed so that the skin layer side of the test piece would be the upper surface, and the durometer hardness was measured using a durometer hardness tester GS719N (manufactured by Tecrock). The hardness at 10 locations was measured and indicated as an average value.
[Abrasion resistance test]: Test method; JIS A1453, 1973
From each laminate, a test piece having a length of 100 mm, a width of 100 mm, and a thickness of 5 mm was cut out and used as a test piece. Using a Taber abrasion tester rotary abrasion tester (manufactured by Toyo Seiki Co., Ltd.), the wear depth (μm) after the surface was worn at 5000 revolutions under a load of 500 g was used as a measure of wear resistance. It shows that it is excellent in abrasion resistance, so that this figure is small.
[Average foamed cell diameter]
From the cross-sectional SEM photograph (1000 times magnification) of the test piece, the diameters of 10 foamed cells were visually measured, and the average value was taken as the average foamed cell diameter.
[Foaming state]
From the cross-sectional SEM photograph (enlarged 1000 times) of the test piece, the foamed state of the foamed resin body was visually observed.
[Foaming ratio]
The density of the unfoamed resin molded body and the density of the foamed foamed resin body were measured using an electronic specific gravity type ED120-T (Mirage Trading Co., Ltd.), respectively, and the ratio (unfoamed resin molded body density / foamed resin) (Body density) was taken as the expansion ratio.
[Surface temperature drop]
After heating the specimen in a 60 ° C. oven for 3 hours, the surface temperature of the specimen is measured in a room at 23 ° C. using a thermography device, Thermo Shot F30 (manufactured by Nippon Avionics), and the surface temperature decreases with time. I investigated.

Examples 1-7
In accordance with the formulation shown in Table 1, a mixture of (A) thermoplastic resin, (B) wood flour, and (C) chemical foaming agent (foamable composition) as a foamed resin body is charged into the second extruder. As a resin base material, (A) a thermoplastic resin and (B) a mixture of wood flour (base material molding composition) is charged into a first extruder and melt kneaded at a molding temperature (die temperature) of 150 to 230 ° C. Then, it was coextruded in a laminated state, and then passed through a cooling sizing at a water temperature of 20 ° C. installed behind the extrusion die to produce a woody resin laminate of length 300 mm × width 250 mm × thickness 30 mm. As the resin substrate, the hollow resin substrate shown in FIG. 7 was adopted. The thickness of the upper and lower surfaces of the hollow resin base material was 3.2 mm, and the thickness of the rib was 2.3 mm. The thickness of the skin layer made of the foamed resin body was 2.0 mm. The test specimen for the test was prepared from the obtained resin laminate, and each physical property measurement was performed. The results are shown in Table 1. Furthermore, the temperature drop on the surface of the laminate was measured. The results are shown in Table 2.
From the cross-sectional SEM photograph of the foamed resin body of Example 1, a large number of bubbles were observed as a whole, the bubbles in the skin layer were 10 to 30 μm, and the average cell diameter was 20 μm. The average thickness of the skin layer was 0.60 mm, the average thickness of the foamed resin body base was 1.40 mm, and it was observed that both portions were continuously connected. The cross-sectional SEM photographs were similarly observed for Examples 2 and below, and the results are shown in Table 1. A thermographic photograph (black and white) in Example 1 is shown in FIG. By this thermography, the surface temperature of the palm center part was 42 ° C. Measurements were similarly made for Example 2 and the following, and the results are shown in Table 1.
In Example 6, irregularities were formed on the die surface (exit) with which the skin layer abuts, and irregularities having a groove depth of 3 mm, a width of 3.5 mm, and a pitch of 3 mm were provided on the skin layer surface. In Example 7, the surface was sanded (polished) with sandpaper # 500 (roughness) to give fine irregularities to the surface of the skin layer.

Example 8
A resin laminate was produced in the same manner as in Example 1 except that ABS resin was used instead of ASA resin. The results are shown in Table 1.

Example 9
A resin laminate was produced in the same manner as in Example 1 except that PP resin was used instead of ASA resin. The results are shown in Table 1.

Comparative Examples 1-5
In Comparative Example 1, a non-foamed resin body without using a chemical foaming agent was used. In Comparative Example 2, a foamed resin body using an excessive chemical foaming agent as compared with the Examples was used. In Comparative Examples 3 and 4, thermal expansion was performed. A foamed resin body was formed on a resin base material using balloons and hollow glass beads, and a foamed resin body not using wood flour in Comparative Example 5, and a resin laminate was produced according to Example 1. The results are shown in Table 1.
The foamed resin body produced using the thermal expansion balloon of Comparative Example 3 has air bubbles uniformly throughout the foamed resin body, and no clear skin layer is formed (see FIG. 3). A thermographic photograph (black and white) in Comparative Example 3 is shown in FIG.
The foamed resin body produced using the hollow glass beads of Comparative Example 4 has few bubbles in the entire foamed resin body, and its distribution is also biased. In addition, a large number of broken glass beads were present in the portion corresponding to the skin layer (see FIG. 4).
The surface temperature of the palm center in each comparative example was measured by thermography, and the results are shown in Table 1.

Example 10
A resin laminate was produced according to Example 1 except that a foamed resin substrate containing wood flour shown in FIG. 8 was employed as the resin substrate. The foamed resin base material is composed of 45 parts by weight of A-2 (ABS resin), 35 parts by weight of A-3 (vinyl chloride resin), 20 parts by weight of B-1 (wood flour) and C-1 (foaming agent). A base molding composition composed of 5 parts by weight of the mixture was foamed and extruded. The expansion ratio was 1.3 times. In the obtained resin laminate, the thickness of the skin layer was 1.0 mm, and the size of the cross section including the skin layer was 30 mm × 70 mm. The thermal conductivity of the laminate was 0.065 W / mK. In the same manner as in Example 10, the temperature change of the surface was measured. The results are shown in Table 2.
When a hollow resin substrate was used as the resin substrate, it was easier to cool than when a foamed resin substrate was used, but in the end, there was almost no change. The initial contact temperature sensation temperature was slightly higher for the foamed resin substrate.

Claims (10)

A flooring material for outdoor use comprising a heat-shielding resin laminate in which a low thermal conductive molded product is laminated in a sheet form on a resin substrate,
The low thermal conductive molded body is
(A) Thermoplastic resin 50 to 95% by mass, (B) Wood powder 5 to 50% by mass [the sum of (A) and (B) is 100% by mass], and (C) Chemical foaming agent ( A) a thermoplastic resin and (B) a foamed resin body obtained by foaming and extruding a foamable composition containing 1 to 5 parts by mass with respect to 100 parts by mass of the total amount of wood flour. The (A) thermoplastic resin Is acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-styrene-acrylate resin (ASA resin), or a mixed resin thereof ,
In the surface layer portion of the foamed resin body, there is a skin layer continuous with the foamed resin body base, and the ratio of the thickness direction of the skin layer is 10 to 33% with respect to the thickness of the foamed resin body,
An outdoor flooring characterized in that the density of the foamed resin body base is 0.50 to 0.90 g / cm ³ and the density of the skin layer is 0.95 to 1.20 g / cm ³ . The outdoor flooring according to claim 1, wherein the skin layer has an average thickness of 0.3 to 1.0 mm. The outdoor flooring according to claim 1 or 2, wherein the foaming ratio of the entire molded body is 1.1 to 2.0 times. Thermal conductivity is 0.3-0.15 W / Mk, The flooring material for outdoor as described in any one of Claims 1-3 characterized by the above-mentioned. Durometer hardness is 75-85, The flooring for outdoors as described in any one of Claims 1-4 characterized by the above-mentioned. The outdoor flooring according to any one of claims 1 to 5, wherein unevenness is provided on the surface of the skin layer. The outdoor flooring according to any one of claims 1 to 6 , wherein the resin base material is a hollow resin base material . The outdoor flooring according to any one of claims 1 to 6 , wherein the resin base material is a foamed resin base material . The thickness of the low thermal conductive body is, outdoor flooring according to any one of claims 1 to 8 you being a 0.7～5.0Mm. The method for producing an outdoor flooring according to claim 1, wherein foaming of the foamable composition and lamination molding onto the resin base material are performed by integral molding by coextrusion molding.