JP2014070367A - Unit floor material, method for manufacturing the same and method for using the unit floor material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unit floor material which has an easy structure, is easily manufactured and constructed, has adequate walking properties and strength, further does not give hotness to a human even when the human mounts thereon with bare foot in direct sunlight and the like, and thereby allows the human to walk thereon with bare foot, and to provide a method for using the floor material.SOLUTION: The unit floor material has a surface part and a leg part. A capacity of the whole of the surface part is larger than a capacity of the whole of the leg part. The surface part and the leg part are integrated. At least a surface of the surface part is made of a resin foam formed by foaming a raw material composition containing a thermoplastic resin and a foaming agent. The leg part is made of a resin which is formed without foaming the raw material composition. The method for manufacturing the same and the method for using the unit floor material are also disclosed.

Description

  The present invention relates to a unit flooring, a method for producing the unit flooring, and a method for using the unit flooring. More specifically, the structure, production and construction are simple, the walking ability and the strength are good, and the direct sunlight is used. The present invention relates to a unit flooring that can be walked barefoot and that does not feel hot even when a person rides barefoot, a method for manufacturing the unit flooring, and a method for using the unit flooring.

  The floors of parts exposed to direct sunlight in the summer, such as around a house veranda, balcony, or outdoor pool, are heated and the surface becomes hot, and humans may not be able to ride with bare feet. In particular, in the floor made of synthetic resin, the tendency becomes remarkable, and the temperature of the sensation becomes high. When a person rides on the floor with bare feet, the person feels hot and cannot walk with bare feet.

Therefore, floor materials having various temperature rise suppression functions or functions that hardly feel heat when a person touches the surface have been proposed.
As a flooring material having a temperature rise suppression function, a floor sheet provided with at least a synthetic resin surface design layer containing a pigment and a synthetic resin light reflection layer provided below the surface design layer And the temperature-rise suppression floor sheet | seat in which the black pigment is not contained in the light reflection layer and the white pigment is contained is proposed (for example, refer patent document 1). This temperature rise suppression floor sheet can reflect light rays (particularly infrared rays) to suppress an increase in surface temperature, and can provide a clear colored pattern or the like.
On the other hand, as a flooring material having a function that makes it difficult to feel heat when a person touches the surface, the flooring material is composed of a base material layer and a heat insulating layer formed on the base material layer. A flooring having pores has been proposed (see, for example, Patent Document 2). Since this flooring material has an open porosity of 5% or less, it is a warm building material that does not generate moisture or the like from the surface and hardly feels cold or heat when a person touches the surface.

However, each of the above flooring materials has a multilayer structure, and the manufacturing process increases and becomes complicated, resulting in an increase in cost. In the former, there is a limit to the suppression of the surface temperature. On the other hand, it cannot be said that the temperature rise can be suppressed to the surface temperature that can be said to be a comfortable temperature, and the reflected heat tends to spread on the flooring material, and the flooring surface has a glare feeling due to the reflected light, which makes the pedestrian uncomfortable. There is a risk of giving or hindering walking.
Furthermore, in the latter case, when a heat insulating layer containing hollow particles having sealed pores inside is supplied on the base material layer and demolded after press molding, the hollow particles compressed by external pressure applied during press molding Since the stress is relieved after demolding and the shape is restored to its original shape, hollow particles are exposed in the form of eczema on the surface of the flooring, or the surface expands unevenly, resulting in the appearance of the flooring surface. In addition to the damage, the pedestrian may be uncomfortable during walking.

  Under these circumstances, the floor is a unit floor that can be walked barefoot while being easy to construct, manufacture, and work, has good walking performance and strength, and does not feel hot even when people ride barefoot under direct sunlight. The material was sought.

JP 2010-31604 A JP 2005-299281 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is simple in construction, manufacture and construction, has good walking ability and strength, and feels hot even when a person rides barefoot under direct sunlight. It is providing the unit flooring which can walk barefoot, its manufacturing method, and the usage method of this unit flooring.

  As a result of intensive studies to solve the above problems, the inventor has integrated the surface portion and the leg portion, and the size (volume) of the surface portion is larger than the size (volume) of the leg portion. In a large unit flooring, at least a surface of the surface part is made of a foamed resin obtained by foaming a specific raw material composition, and the leg part is made of a resin that does not foam the raw material composition, the raw material composition A step of preparing a product, after the leg portion having a size (volume) smaller than the surface portion is cooled and molded without foaming using the raw material composition, The method of manufacturing the unit floor material including the step of core back injection molding while foaming and the method of using the unit floor material such as installing the unit floor material in a place where the user walks with bare feet are easy to configure, manufacture and construct. And walking and It is a unit flooring that is not only warm, but does not feel hot even when riding barefoot under direct sunlight, etc., and by using the unit flooring, Even in places where walking was impossible, it was found that it was possible to walk barefoot with simple construction, and the present invention was completed.

  That is, according to the first invention of the present invention, it has a surface portion and a leg portion, the volume of the entire surface portion is larger than the volume of the entire leg portion, and the surface portion and the leg portion are integrated. A unit floor material capable of bare foot walking, wherein at least a surface of the surface portion is made of a foamed resin obtained by foaming a raw material composition containing a thermoplastic resin and a foaming agent, and the leg portion is formed of the raw material composition. A unit flooring comprising a resin that does not foam an object is provided.

  Further, according to the second invention of the present invention, a step of preparing a raw material composition containing a thermoplastic resin and a foaming agent, after forming the leg portion without foaming using the raw material composition, There is provided a method for producing a unit flooring according to the first aspect of the present invention, comprising a step of core back injection molding while foaming at least the surface of the surface portion with a mold having a variable volume.

  Moreover, according to the 3rd invention of this invention, the usage method of the unit flooring of the 1st invention characterized by installing in the location which walks with a bare foot is provided.

  According to the unit flooring of the present invention, the manufacturing method thereof, the method of using the unit flooring, and the like, in the first invention, at least the surface of the surface portion having a size (volume) larger than the leg portion is a thermoplastic resin. And a foaming resin obtained by foaming a raw material composition containing a foaming agent, and the leg portion is a unit flooring made of a resin that does not foam the raw material composition. There is an effect that it is a unit flooring that has a sufficient strength as a flooring material and can be walked barefoot without being felt hot even when a person rides barefoot underneath.

  Further, in the second invention, the unit flooring manufacturing method of the first invention includes specific steps such as a step of preparing a raw material composition and a core back injection molding step. The unit floor material of the present invention, which is molded without foaming and has excellent load resistance and durability, has an effect that it can be produced simply, effectively, economically and integrally in a short time.

  Further, in the third invention, since it is a method of using the unit flooring of the first invention characterized in that it is installed at a place where a person walks with bare feet, humans have been barefooted to feel hot under direct sunlight. There is an effect that a place where the user could not get on can be easily and easily walked, and can be made into a floor that does not feel hot even if a person rides barefoot under direct sunlight.

FIG. 1 is a schematic diagram including a left side view, a plan view, and a right side view showing an example of a unit flooring of the present invention. FIG. 2 is a schematic view showing an example of a method for producing a unit flooring according to the present invention. FIG. 3 is a schematic view showing a state after the mold cavity is enlarged in the manufacturing method of FIG.

Hereinafter, the unit flooring of the present invention, the manufacturing method thereof, and the method of using the unit flooring will be described specifically and in detail with reference to the drawings.
1. Unit Floor Material (1) Configuration The unit floor material of the present invention has a surface portion and a leg portion, the volume of the entire surface portion is larger than the volume of the entire leg portion, and the surface portion and the leg portion are The unit flooring is an integral unit, wherein at least the surface portion is made of a foamed resin obtained by foaming a raw material composition containing a thermoplastic resin and a foaming agent, and the leg portions foam the raw material composition. It is a unit flooring characterized in that it is made of an unrestrained resin.
Hereinafter, an example of an embodiment of a unit flooring of the present invention will be described in detail with reference to the drawings.

(Overall shape)
In FIG. 1, a unit flooring 1 of the present invention has a rectangular surface portion 2 and leg portions 4 divided into nine parts, and the surface portion 2 and the leg portions 4 are integrated via a frame body portion 3. It is configured as.
The configuration of the unit flooring 1 is not limited to the above, and a rectangular surface portion 2 divided into four may be provided on one frame body portion 3, or a configuration in which one surface portion 2 is provided. It may be said.
When only one rectangular surface portion 2 is provided on one unit flooring 1, the surface portion 2 and the leg portion 4 may be directly integrated without using the frame body portion 3. Good.
The shape of the surface portion 2 may be a polygonal shape, a circular shape, an elliptical shape, or the like other than a rectangle.

  As the unit flooring 1 of the present invention, the surface portion 2 and the leg portion 4 are integrated, the surface portion 2 is at least partly, for example, at least the surface is made of foamed resin, and the leg portion 4 is Any other shape may be used as long as it is made of a resin that does not foam, but it is obtained by a manufacturing method in which at least the surface of the surface portion 2 is foamed and the legs are not foamed by an injection molding method as described later. It is preferable from the viewpoint of performance such as load resistance, impact resistance and durability of the unit flooring and from the economical aspect.

(leg)
The leg part 4 is provided in order to make the bottom of the surface part 2 (or the frame part 3) a drainage space.
The shape, size, spacing, etc. of the leg part 4 are not particularly limited, but are appropriately designed in consideration of load resistance, impact resistance, durability, drainage, moldability, designability, etc. It is preferable.
A connecting portion 5 for connecting adjacent unit floor materials may be provided at the peripheral edge of the frame body portion 3 (or the surface portion 2).

The leg part of the unit flooring of the present invention is cooled before the surface part because the size (volume) is smaller than the surface part in the manufacturing process, and foams the raw material composition containing the thermoplastic resin and the foaming agent. It is necessary to be made of a resin that is not allowed. Here, “do not foam” means that the raw material composition is cured in a non-foamed state, but also includes those slightly foamed within a range that does not affect the strength. Usually, it is assumed that the expansion ratio is less than 1.05 times.
Since the leg 4 is made of a resin that is not foamed, the cross-sectional shape in the thickness direction of the unit flooring 1 can be reduced to a reverse concave shape or an inverted U shape so as to reduce the weight if the strength required for the leg 4 is secured. It is good also as a shape or an inverted V shape.
In the present invention, the volume of the entire surface portion needs to be larger than the volume of the entire leg portion, but the volume ratio is such that the volume of the entire surface portion: the volume of the entire leg portion is 5: 5 to 7: It is preferably about 3. If the volume of the entire surface portion is larger than 7: 3, the effect of having sufficient strength as a flooring material may not be obtained. In addition, if the volume of the entire surface portion is smaller than 5: 5, the walking performance is good, and even if a person rides with bare feet under direct sunlight, the human body does not feel hot and can walk barefoot. May not be obtained. The “volume of the entire surface portion” in the present specification refers to the volume of the entire surface portion regardless of whether the resin is foamed or not foamed.

(Surface part)
The surface portion of the unit flooring of the present invention is made of a foamed resin in which at least the surface is foamed with a raw material composition containing a thermoplastic resin and a foaming agent.
Here, in this specification, “at least the surface is made of a foamed resin obtained by foaming a raw material composition containing a thermoplastic resin and a foaming agent” means that at least on the surface of the surface portion 2 that is a walking surface. It means that the part or the entire surface is made of a foamed resin. Accordingly, the peripheral corner portion, the side surface portion, the back surface portion, and the core portion of the surface portion 2 are made of non-foaming resin, the surface portion 2 is made of foamed resin, and the frame portion 3 in which the surface portion 2 is integrated is foamed. Including those made of non-resin.
The surface shape of the surface portion 2 may be a flat shape, but is preferably a convex curved shape in consideration of the drainage of the surface portion 2.
If the surface portion 2 has a convex curved surface and a communication hole is provided in a joint portion (not shown) formed between adjacent surface portions 2, the unit flooring 1 has an effect of excellent drainage. There is.
The surface may be provided with a concavo-convex pattern having a height or depth that does not impair drainage.
Since the surface portion of the unit flooring of the present invention is made of a foamed resin obtained by foaming a raw material composition containing a thermoplastic resin and a foaming agent, it is excellent in heat feeling when a person touches the surface, and human Even if you ride barefoot, you will not feel hot.

In the present invention, the foamed resin is preferably foamed at a foaming ratio of 1.05 to 10 times, more preferably 1.1 to 5 times after preparing the raw material composition. “Foaming ratio” means a value obtained by dividing the density of an unfoamed raw material composition by the density of the raw material composition after foaming.
If the expansion ratio is lower than 1.05 times, the unit floor material may not have a desired heat feeling that can be barefoot, and if it is higher than 10 times, the strength and load resistance of the surface portion will decrease. The unit flooring may be easily damaged.

  The frame part 3 may be made of foamed resin or non-foamed resin, but the surface part is loaded so that it can withstand a load during walking or a concentrated load such as a leg part of a chair. It may have a leg with a shape that does not damage the ground and is arranged so that the force is distributed so as to be received.

(2) Raw material composition The raw material composition used for the unit flooring of the present invention needs to contain a thermoplastic resin and a foaming agent. The thermoplastic resin used in the present invention is not particularly limited. For example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, polybutene, chlorine Olefin resins such as polyethylene, acrylic resins such as polystyrene, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene resins, polymethyl acrylate, ethylene-ethyl acrylate copolymers, and chlorine-based resins such as polyvinyl chloride Resin, fluororesin such as polyfluorinated ethylene, polyamide resin such as 6-nylon, 66-nylon, 12-nylon, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, ABS resin, polycarbonate, poly Acetal, polyphenylene sulfide, polyether ether ketone, polyether imide, silicone resin, thermoplastic urethane, various elastomers, and the like.
In particular, those having a melt tension or elongational viscosity suitable for foaming are preferred, and for example, polyethylene, polypropylene, polystyrene, ABS resin, polyvinyl chloride and the like are suitably used. Furthermore, as the polyethylene, polypropylene, etc., a finely crosslinked resin having an adjusted extensional viscosity characteristic is preferable.
These resins may be used alone or in combination of two or more.

The foaming agent used in the present invention is not particularly limited. For example, organic or inorganic chemical foaming agents such as azodicarbonamide (ADCA) and azoisobutyronitrile, or carbon dioxide gas, nitrogen, argon, neon, helium, Physical foaming agents such as oxygen can be used. These may be used alone or in combination of two or more.
In addition, you may add foaming adjuvants, such as a zinc oxide, to a chemical foaming agent as needed.
For reasons such as obtaining a good appearance, a foaming agent having a gas amount of about 15 to 60 ml / g during foaming is preferred. In addition, an inorganic foaming agent is desirable in a region where the molding temperature is high, and an organic foaming agent is desirable in a region where the molding temperature is low. Moreover, since it mixes with a thermoplastic resin, it is preferable that a foaming agent is a pellet form or a sheet form as a masterbatch. For example, by using a pelletized masterbatch foaming agent, it can be easily mixed with a thermoplastic resin, and there is no scattering of the foaming agent at the time of mixing, the mixing time can be shortened, the dispersibility is excellent, and a uniform fine foam molded product can be obtained. Can be obtained.

As an example of a chemical foaming agent, as a commercially available product, for example, trade name “Celmic MB9082” manufactured by Sankyo Kasei Co., Ltd. [inorganic foaming agent, foaming temperature: 200 to 240 ° C., gas amount: 15 ml / g ], "Celmic MB9073" [inorganic foaming agent, foaming temperature: 170-210 ° C, gas amount: 30 ml / g] and "Celmic MB9043" [Organic ADCA foaming agent, foaming temperature: 160-190 ° C, gas amount] : 55 ml / g].
Foamable microcapsules can also be used. This is a fine particle of about several tens of μm with a low-boiling core coated with a thermoplastic shell. For example, trade name “ADVANCEL” manufactured by Sekisui Chemical Co., Ltd. [foamed fine particle, foaming temperature: 115 to 170 ° C., Foaming ratio: 30 to 80 times].

  As the addition amount of the foaming agent, it is preferable to add 1 to 10% by weight of the foaming agent based on the whole raw material composition. If it is less than 1% by weight, it is not preferred because there is a possibility that the walking ability by foaming is good and the effect of being able to walk barefoot is not seen. On the other hand, if it is more than 10% by weight, the physical properties of the molded product may be inferior.

  In the present invention, the foamed resin raw material composition contains a thermoplastic resin and a foaming agent, but various additives may be blended as desired. The additive is not particularly limited, and examples thereof include flame retardants such as metal hydrated oxides such as aluminum hydroxide and magnesium hydroxide; calcium carbonate, calcium oxide, barium carbonate, magnesium hydroxide, aluminum hydroxide, clay, Fillers such as talc and mica; plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate, dihexyl phthalate, diisononyl phthalate, phosphate ester, chlorinated paraffin, trimellitic acid ester; calcium stearate, inorganic salt And stabilizers such as organotin compounds; lubricants; antioxidants; colorants such as pigments; The blending ratio of the additive is preferably 0.1 to 3.0% by weight based on the whole raw material composition.

The raw material composition of the foamed resin is prepared by mixing various additives as necessary in addition to the thermoplastic resin and the foaming agent. The mixing method is not particularly limited, and examples thereof include a hot blend method and a cold blend method.
In the present invention, based on the whole raw material composition, 90 to 99% by weight of polypropylene is used as the thermoplastic resin, and 1 to 10% by weight of carbon dioxide gas is used as the foaming agent, more preferably 92 to 90% of polypropylene is used as the thermoplastic resin. 98% by weight, 2-8% by weight of carbon dioxide gas used as a foaming agent, using a manufacturing method by injection molding consisting of core-back injection foaming, the performance of both the surface part and the leg part is particularly well balanced Since it can form, it is preferable. However, various additives other than the thermoplastic resin and the foaming agent are not included in the calculation.

  In addition, it is preferable that the walking time of the foamed resin or the bare foot walking is 30 seconds or more when standing and standing on the unit flooring under the direct sunlight with the bare foot in the fine weather in summer.

2. Production method The production method of the unit flooring of the present invention is not particularly limited, but the step of preparing a raw material composition of a foamed resin containing a thermoplastic resin and a foaming agent, the leg portion using the raw material composition is prepared. A preferable example is a manufacturing method including a step of core-back injection molding while foaming at least the surface of the surface portion with a mold having a variable cavity volume after molding without foaming. A method of foaming the surface and injection molding without foaming the legs is preferable from the viewpoint of performance such as strength, load resistance and durability of the unit flooring and cost. Further, the injection molding step is preferably because the core back injection molding method is integrally formed of a resin that does not foam the legs of the unit flooring and a resin that foams the surface, and is molded in one step. .

(1) Step of preparing raw material composition In the present invention, the step of preparing the raw material composition includes a method of dissolving an inert gas in a thermoplastic resin under high pressure, and the inert gas is heated in a molten state. There are a method of dissolving in a plastic resin and a method of dissolving in a solid state thermoplastic resin, either method may be adopted, or both may be used in combination.
In one embodiment of the present invention, after feeding the polypropylene resin into the pressure resistant chamber, carbon dioxide gas whose pressure is adjusted to 5.5 MPa is used with respect to a ratio of 95% by weight (parts by weight) of the polypropylene resin. Carbon dioxide gas was introduced into the pressure-resistant chamber so as to have a ratio of 5% by weight (parts by weight), and the pressure of the carbon dioxide gas was maintained at 5.5 MPa and the temperature at 45 ° C. for 2 hours in the pressure-resistant chamber, Dissolve in plastic resin.
The raw material composition which consists of a carbon dioxide containing thermoplastic resin is prepared by the above process.

(2) Injection molding process In the present invention, as the injection molding process, the core back injection foam molding is integrally molded as a resin that does not foam the legs of the unit flooring, and a resin that foams the surface, And since it shape | molds in one process, it is preferable.
Core back injection foam molding uses a mold with a variable cavity volume, fills the raw material composition into a small volume cavity, and then expands the cavity volume to promote bubble generation, In the present invention, a mold that has a variable cavity volume on the surface portion of the unit floor material, a resin that does not foam the legs of the unit floor material having a smaller size (volume) than the surface portion, The surface portion is integrally molded as a resin foamed by core back injection foam molding, and can be molded in one step.
The core back injection foam molding in the present invention is not limited to the case where the fixed mold is a female mold and the movable mold is a male mold, but the fixed mold is a male mold and the movable mold is a female mold. May be.
Further, the plurality of holes for forming the leg portions may be provided on the cavity surface side of the fixed mold, or may be provided on the cavity surface side of the movable mold.

An example of the method for producing the unit flooring of the present invention will be described in detail with reference to FIGS.
2 and 3 show a production method for producing the unit flooring 1 using the apparatus 10 for core back injection molding using the raw material composition comprising the carbon dioxide-containing thermoplastic resin. FIG. 2 is a schematic view showing an example of a method for producing a unit flooring according to the present invention. FIG. 3 is a schematic view showing a state after the cavity of the mold shown in FIG. 2 is enlarged. 2 and 3, in the core back injection molding apparatus 10, a cavity 14 is provided between a fixed die 13 and a movable die 12 provided so as to be movable back and forth in the direction in which the operating rod 16 is provided. ing.
Accordingly, when the operating rod 16 moves in the direction of the hydraulic cylinder 17 by the action of the hydraulic cylinder 17, the movable mounting plate 18 and the movable die 12 are moved together with the operating rod 16, and the cavity 14 is enlarged.

The shape of the cavity 14 is formed to be the same as the shape of the surface portion 2 of the unit flooring 1 when enlarged. The raw material composition is supplied to the cavity 14 from the injection cylinder 15 through a runner part and a gate part (both not shown) provided in the fixed mold 13.
On the cavity 14 surface side of the fixed mold 13, a plurality of holes for forming the leg portions 4 of the unit flooring are provided in the direction of the injection cylinder 15.
In FIG. 2, the raw material composition supplied into the cavity 14 is first filled in the holes to form the legs 4a of the unit flooring 1a.
At this time, since the hole portion is narrower than the other space portion in the cavity 14, the raw material composition is preferentially cooled in comparison with other portions in a state in which the raw material composition is not foamed. Solidification proceeds.

Next, as shown in FIG. 3, when the movable die 12 is moved by the hydraulic cylinder 17 to enlarge the cavity 14, foaming of the raw material composition integrated with the leg portion 4 b proceeds, and the surface portion 2 b having a predetermined foaming ratio is formed. The formed unit flooring 1b is obtained.
Therefore, the surface portion 2b made of the foamed raw material composition and the leg portion 4b made of the raw material composition that is not foamed can be molded in one step.

3. Use This invention provides the usage method which installs the said unit flooring in the location which walks with a bare foot.
As a place to walk with bare feet, there are verandas, balconies, etc., and the present invention installs the unit flooring at these places, so that the place where you could not walk bare feet because it feels hot under the hot weather in summer, etc. It can be made to walk barefoot.
It does not specifically limit as an installation method, In addition to the method of connecting and installing the unit flooring of this invention in the said applicable said location, it can also install as stepping stones, such as a garden. Installation is basically achieved simply by placing the unit flooring of the present invention.
As a result, there is no need for large-scale construction, and the floor can be easily walked at low cost and can be walked barefoot even in hot weather.

EXAMPLES Hereinafter, although this invention is demonstrated in more detail using an Example, this invention is not limited to these Examples.
The measuring method of each physical property value in the present invention is shown below.

1. Evaluation method (1) Surface temperature (unit: ° C.): Measured with a non-contact surface thermometer.
(2) Experience with bare feet: The following shows the experience when one adult gets on the unit floor surface with bare feet in fine weather in summer.
(Double-circle): It does not feel hot and can still for 30 seconds or more.
○: I feel hot, but I can stand for more than 30 seconds.
X: Feels hot and cannot stand 30 seconds with bare feet.
(3) Load resistance ○: The unit floor material is not damaged even if one adult (total load = 72Kg) gets on the surface of the unit floor material.
X: The unit flooring was damaged when one adult (total load = 72Kg) got on the surface of the unit flooring.

2. Examples and Comparative Examples (Example 1)
The raw material composition is obtained by adjusting the thermoplastic resin to 95% by weight (parts by weight) and the carbon dioxide gas to 5% by weight (parts by weight) as the foaming agent. A unit flooring of 300 mm × 300 mm × total height 20 mm having a leg portion of 8 mm and a surface portion made of a foamed resin having a foaming ratio of 1.1 times was molded.

(Example 2)
The raw material composition is obtained by adjusting the thermoplastic resin to 95% by weight (parts by weight) and the carbon dioxide gas to 5% by weight (parts by weight) as the foaming agent. A unit flooring of 300 mm × 300 mm × total height 60 mm having a leg portion of 8 mm and a surface portion made of foamed resin having a foaming ratio of 5 times was molded.

(Comparative Example 1)
A unit floor material having the same shape as in Example 1 made of polypropylene was molded without adding a foaming agent.

(Comparative Example 2)
The raw material composition is obtained by adjusting the thermoplastic resin to 95% by weight (parts by weight) and the carbon dioxide gas to 5% by weight (parts by weight) as the foaming agent, and molding a unit flooring of 300mm x 300mm x total height 60mm. did.
In addition, when supplying the raw material composition to the cavity, the size of the cavity is expanded in advance so as to be the same as the size of the unit flooring, and then the raw material composition is adjusted while adjusting the supply amount of the raw material composition. A unit flooring made of a foamed resin was obtained by foaming the foaming ratio so that the foaming ratio of the leg portion as well as the surface portion was 5 times without changing the size of the cavity.

3. Evaluation As is apparent from Table 1, when Examples 1 and 2 are compared with Comparative Examples 1 and 2, “a raw material in which at least the surface portion of the unit flooring of the present invention contains a thermoplastic resin and a foaming agent” In Comparative Example 1, the surface temperature is obtained from a comparative example that does not satisfy the requirement that the composition is made of a foamed resin obtained by foaming the composition and the leg portion is made of a resin that does not foam the raw material composition. Even when the temperature was 44 ° C., when riding with bare feet, it felt hot and could not walk. Moreover, in the comparative example 2, when a person got on the unit floor material, the unit floor material was damaged.
Compared with these, the unit flooring according to the present invention was able to walk in Example 1 because it did not feel hot even when riding barefoot, although the surface temperature was the same as in Comparative Example 1. . Moreover, in Example 2, the bodily sensation was further improved.
Therefore, according to the unit flooring of the present invention, for example, it has been clarified that the unit flooring is capable of walking barefoot even under hot weather.

  From the above, in the unit flooring of the present invention, the manufacturing method thereof, and the method of using the unit flooring, at least the surface of the surface portion, which is a characteristic point, foams the raw material composition containing the thermoplastic resin and the foaming agent. It is said that it is a unit floor material that is made of foamed resin and the leg portion is made of a resin that does not foam the raw material composition, so that the experience with bare feet does not become hot, and it can be walked bare feet. It is clear that it has great technical significance.

  According to the unit flooring of the present invention, the manufacturing method thereof, and the method of using the unit flooring, the structure is simple and the walking ability is good, and it feels hot even when a person rides barefoot under direct sunlight. There is provided a unit floor material that can be walked barefoot and a method of using the floor material. Therefore, the industrial applicability of the present invention is extremely large.

1, 1a, 1b Unit floor material 2, 2a, 2b Surface portion 3 Frame portion 4, 4a, 4b Leg portion 5 Connecting portion 10 Core back injection molding device 11 Mold 12 Moving die 13 Fixed die 14 Cavity 15 Injection cylinder 16 Actuating rod 17 Hydraulic cylinder 18 Moving mounting plate

Claims (3)

A unit flooring having a surface part and a leg part, wherein the volume of the whole surface part is larger than the volume of the whole leg part, and the surface part and the leg part are integrated;
At least the surface of the surface portion is made of a foamed resin obtained by foaming a raw material composition containing a thermoplastic resin and a foaming agent,
The unit flooring, wherein the leg portion is made of a resin that does not foam the raw material composition.   A step of preparing a raw material composition comprising a thermoplastic resin and a foaming agent; after forming the leg portion without foaming using the raw material composition, at least the surface portion by a mold having a variable cavity volume; The method for producing a unit flooring according to claim 1, comprising a step of core back injection molding while foaming the surface. 2. The method for using a unit flooring according to claim 1, wherein the unit flooring is installed at a place where the user walks with bare feet.

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