JP2000263624A - Manufacture of extrusion foamed composite, and foamed composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion foamed composite having a core material of good uniformity of foamed cells, good closed cell property and high expansion ratio and having a light weight and high rigidity, and a method for manufacturing it. SOLUTION: A method for extrusion molding of a foamed composite comprises the step of coating an outer periphery of a core material 100 foamed from a foamable resin for the core material with a skin material 30. The method comprises the steps of extruding a skin material 30 from a second die 33 to an outside of the core material 100 while forming the core material 100 by extruding and foaming the foamable resin 10 for the core material from nozzles disposed in a plurality of rows and stages from a first die 2, immediately guiding the skin material 30 to a cooling sizing 4, forcibly bringing the skin material 30 into contact with an inner surface of the sizing 4 by a foaming force of the foamable resin, and covering an outer surface of a foam 104 made of the material 100 of a plurality of rows and stages with the skin material 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam composite used in the fields of civil engineering and construction materials, for example, concrete forms, walls, floors, ceilings, shelves, etc. Material)
And a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, there has been known a method in which a thermoplastic resin containing a foaming agent is extruded from an extruder, foamed to form a core material, and a skin material is coated on the outer periphery of the core material to form a foamed composite. Have been. Extrusion foaming is advantageous in terms of production volume and production cost because foam can be produced continuously.
Widely used.

However, it is difficult to form a thick core material into a desired shape by extrusion foaming and to cover the core material with a skin material. That is, even if the foaming resin for the core material containing the foaming agent is accurately extruded into a plate shape or the like, the extruded foamable resin for the core material foams immediately after exiting the die of the extruder. Therefore, the extruded material swells three-dimensionally and largely deforms and curves from the desired shape. Therefore, in order to make the foam core material thus obtained into a desired shape, the shape is corrected by cutting or hot pressing and used. Therefore, the manufacturing process of the foamed composite is complicated, and the material is wasteful.

In order to eliminate such complexity and waste,
A long body of foamed plastic molded in advance is put into an extruder, and the skin material is covered with a die to obtain a desired shape.
There is a method for improving the surface strength and bending strength of a composite (for example, Japanese Patent Application Laid-Open No. 8-336876). However,
This method requires two steps because a preformed foam is used.
There is a disadvantage that the process becomes a process and the production cost increases.

Japanese Patent Application Laid-Open No. 4-282237 discloses a method for producing a foam with a skin layer, in which the foam is extruded and cooled to a low temperature with a homing die in order to obtain a skin layer on the surface of the foam. ing. However, in this method, it is difficult to obtain a skin layer having a very small skin layer and a thickness of 0.5 mm or more.

Further, Japanese Patent Application Laid-Open No. 2-194922 discloses a method in which the inside is covered with a foamed resin layer and the entire outer periphery is covered with a non-foamed resin layer. However, in this method, the temperature of the foamed resin rises close to the temperature of the skin material to be coated, because the foam material as the core material and the skin material merge in the die. As a result, the melt viscosity of the foamed resin also decreases, and the resin pressure in the die also decreases, resulting in a target density of 0.14 to 0.02 g /
Even if an attempt is made to obtain a core material having a high expansion ratio of 1 (liter), the uniformity and independence of the cells of the foam become insufficient, and a satisfactory foam composite cannot be obtained. In addition, the extruded foam composite is required to be lightweight and have high rigidity in order to secure strength during use.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has uniformity of foam cells, good closed cell properties, a core material having a high expansion ratio, light weight and rigidity. An extruded foam composite having a high hardness and a method for producing the same are provided.

[0008]

According to the first aspect of the present invention, a foaming resin for a core made of a thermoplastic resin containing a foaming agent is extruded from a first die of a first extruder. A skin material made of an expandable thermoplastic resin is extruded from a second die of a second extruder, and is made of the foamable resin for a core material outside the first die and the second die provided at the tip of both extruders. A method of extrusion-molding a foamed composite comprising the core material and the outer skin material covered with the skin material, wherein the first die is provided with a plurality of nozzles arranged in a plurality of rows and a plurality of stages to form the foamable resin for a core material. While the core material is formed by extruding and foaming the core material, the surface material is extruded from the second die to the outside of the core material, and the surface material is immediately led to cooling sizing, and the foamable resin for the core material is formed. Of the above skin material by the foaming power of The extruded foam composite is obtained by covering the outer surface of a foam consisting of a plurality of rows and a plurality of stages of a core material formed of the above foamable resin for the core material by pressing against the inner surface of the cooling sizing. A method for producing an extruded foam composite, which is characterized by being produced.

The most notable point in the present invention is that the foamable resin for the core material is continuously extruded from the nozzle of the first die in a plurality of rows and a plurality of stages, while the skin material is extruded by a second extruder. Continuously extruded from the second die,
The foaming resin for the core material is foamed to form a foam consisting of a plurality of rows and a plurality of stages of the core material, while the skin material is coated on the outer periphery of the foam, and then immediately cooled to a desired shape by cooling sizing. It is shaping.

In the present invention, the foaming resin for the core material extruded in a plurality of rows and a plurality of stages is foamed at the outlet of the first die, and the skin material is coated around the core material obtained by the foaming. . As a result, a foam having a high magnification can be obtained in which the foamed cells in the core material are uniform and the foamed cell membrane has closed cells without breaking. If a skin material is joined around the foamable resin for the core material in the die, the foamable resin for the core material is covered with the skin material, or the foamable resin for the core material is foamed in the die, and the inside of the die is expanded. In the case of covering the skin material with the above, the above effects cannot be obtained.

Further, the surface of the foam made of the excellent core material is coated with the skin material almost simultaneously with the foaming of the core material. Therefore, it is possible to obtain an effect that fusion between the skin material and the foam and fusion between the core materials can be reliably performed. The core material extruded and foamed from each nozzle is formed in a plurality of rows and a plurality of stages, and is fused to the core materials adjacent to each other. Therefore, the rigidity of the extruded foam composite is also improved.
Also, the extruded foam composite is lightweight because it is composed of a foam and a skin material.

Therefore, according to the present invention, there is provided a method for producing an extruded foamed composite which is excellent in uniformity and closed-cell properties of foam cells, has a core material having a high expansion ratio, is lightweight and has high rigidity. can do.

The above-mentioned cooling sizing refers to molding by a cooling mold to obtain a desired shape. In addition, cooling shaping to the desired shape means that the skin material is cooled by cooling sizing,
Forming while cooling by increasing the degree of adhesion of the foamed composite to cooling sizing by the foaming pressure of the foamable resin for the core material.

As the skin material, a non-foaming or low-foaming thermoplastic resin is used. The non-foamable thermoplastic resin does not use a foaming agent, and the low-foamable thermoplastic resin uses a small amount of a foaming agent. As the thermoplastic resin, polystyrene, acrylic butadiene styrene (AB)
S), styrene resins such as resins, various polyethylenes, polypropylene resins, polyolefin resins such as copolymers of polypropylene and α-olefin, polyvinyl chloride resins, vinyl acetate resins, various nylon resins, various acrylic resins,
There are polycarbonate resins and their mixed resins.
In addition, fillers such as talc, calcium carbonate, mica, and the like can be added to these resins, or various pigments can be used.

The present method is particularly effective because
A resin obtained by adding a filler to a styrene resin or a polypropylene resin. In this case, the rigidity is high and the cost is relatively low. Also, in order to improve the appearance of the product,
It is preferable to add a small amount of a foaming agent to the above-mentioned skin material and use it as a low foamed body.

Further, as the foamable resin for the core material,
A thermoplastic resin containing a foaming agent is used. As the thermoplastic resin, those similar to the thermoplastic resins shown for the skin material can be used. Examples of the foaming agent include volatile foams such as aliphatic hydrocarbons such as propane, n-butane, i-butane, pentane and hexane, and cycloaliphatic hydrocarbons such as cyclobutane, cyclopentane and cyclohexane. Agent, azodicarbonamide,
There are decomposable blowing agents such as azobisisobutylnitrile and sodium bicarbonate. Further, air, carbon dioxide, nitrogen, or the like can be used as the inorganic foaming agent. Further, these foaming agents can be appropriately mixed and used.

The amount of the foaming agent added to the foaming resin for the core material is preferably 3 to 15% by weight. As a method of adding a volatile foaming agent, foamed resin beads contained therein can be used, and for example, a foaming agent can be injected in an extruder. In addition, the adjustment of the magnification of the foam
It can be freely changed depending on the amount of the foaming agent added, the nozzle diameter, the number of revolutions of the extruder, the temperature, and the take-up speed.

The nucleating agent used to obtain a more uniform foam cell includes polyethylene wax, ethylene bisamide, hexabromocyclododecane, and lower alkyl methacrylate containing 5% by weight or more of lower alkyl methacrylate units. At least one selected from an organic nucleating agent such as an ester polymer, an inorganic nucleating agent such as talc and silica, and water is used. These nucleating agents are used in an amount of 0.2 to 5 wt%, preferably 0.4 to 5 wt%, based on the foaming resin for the core material.
It is preferable to contain 2.0 wt%.

When a gap is provided between the outlet of the foaming resin for the core material and the outlet of the skin material, for example, 7 to 50
A core material having a high expansion ratio of 2 times can be obtained.

Next, as in the second aspect of the present invention, the first
A die is provided between the second extruder and the second extruder so as to control the temperature of the foaming resin for the core material in the first die to be at least 20 ° C. lower than the temperature of the skin material. It is preferable to have a mechanism. In this case, the foaming resin for the core material can be extruded at a low temperature and can be extruded by applying an extremely high back pressure in the first die, and the uniformity and independence of the high magnification foam cell can be obtained. it can.

That is, when a foaming agent is added to the foaming resin for the core material and extruded, the melt viscosity of the resin generally decreases, no back pressure is applied in the extruder, and the back of the outlet of the first die is further reduced. No pressure is applied and the expansion ratio does not increase. However, as described above, when the temperature is adjusted to lower the resin temperature, the melt viscosity of the resin increases, so that the above-mentioned high back pressure becomes possible, and the above-mentioned effect is obtained. As the heat insulating mechanism, for example, a heat medium chamber method, a heat insulating plate method, an air cooling chamber method, or the like as shown in the embodiment is used.

Next, as in the third aspect of the present invention, the foamable resin for the core material is provided in the first die and is provided in a plurality of rows and a plurality of stages of nozzles each having an opening area of 30 mm ² or less. It is preferable that the foam is extruded from the foam and foamed at a foaming ratio of 7 to 50 times. In this case, the back pressure of the expandable resin for the core material is increased, and the expansion ratio can be increased.

Next, the opening area of the nozzle is 30 mm ²
If it is less than the same nozzle, the same columnar foam is molded from the same nozzle, and the foaming ratio of each foam becomes more uniform. The foam formed from the nozzle may have a circular shape, an elliptical shape, or a polygonal shape having a square shape or more. The lower limit of the opening area of the nozzle is preferably set to 0.03 mm ² from the viewpoint of difficulty in pressurization and clogging. When the expansion ratio is less than 7 times, the weight reduction becomes insufficient and the cost may increase. On the other hand, when the expansion ratio exceeds 50 times, the closed cell properties may decrease and the foam may have low strength. is there.

Next, as in the invention of claim 4, the foamable resin for the core material is composed of 75 to 97.8% by weight of a polystyrene resin, 2 to 20% by weight of a foaming agent and 0.2 to 5% of a nucleating agent. %, And the skin material is preferably a styrene-based thermoplastic resin. In this case, the polystyrene resin is a general-purpose resin that is relatively inexpensive in raw materials, has high holding power for the blowing agent, and has good moldability. In addition, the use of the nucleating agent improves the uniformity of the foam cells, increases the expansion ratio, and is advantageous in terms of rigidity per weight and cost.

If the amount of the polystyrene resin is less than 75% by weight, there is a problem that the foaming becomes too high and the strength is weak, while if it exceeds 97.8% by weight, the problem is that the expansion ratio is low and the weight reduction cannot be sufficiently achieved. is there.

If the amount of the foaming agent is less than 2% by weight, a high expansion ratio cannot be obtained, while if it exceeds 20% by weight, the expansion ratio becomes too high, resulting in a core material having low strength. In addition, there is a problem that gas is formed between the skin material and the core material due to the excess foaming gas, so that the skin material and the core material are not easily fused. Further, if the nucleating agent is less than 0.2% by weight, it is difficult to achieve uniformity of the foamed cells, while if it exceeds 5% by weight, the uniformity of the foamed cells is not improved, which is economically disadvantageous. In addition, preferably 1 to
4% by weight.

Next, as in the invention of claim 5, the skin material comprises a main component consisting of 70 to 30% by weight of a styrene-based thermoplastic resin and 30 to 70% by weight of an olefin-based thermoplastic resin. It is preferable to mix 1 to 7% by weight of a thermoplastic elastomer with respect to 100% by weight.

In this case, the use of the olefin-based thermoplastic resin improves the chemical resistance, which is a disadvantage of the styrene-based thermoplastic resin. In addition, by adding a thermoplastic elastomer, compatibility with each other is improved, and a product having excellent chemical resistance, heat resistance, and appearance can be obtained.

70% by weight of the above styrene thermoplastic resin
If the amount exceeds 30%, the chemical resistance and heat resistance deteriorate. On the other hand, if the amount is less than 30% by weight, there is a problem of poor fusion with the core material. If the olefin-based thermoplastic resin is less than 30% by weight, there is a problem that chemical resistance and heat resistance are deteriorated, while if it is more than 70% by weight, there is a problem that the fusion property with the core material becomes poor. .

When the content of the thermoplastic elastomer is less than 1% by weight, the compatibility between the olefin-based thermoplastic resin and the styrene-based thermoplastic resin becomes poor, and there is a problem of poor appearance. On the other hand, if it exceeds 7% by weight, there is a problem that the rigidity of the skin material is reduced, and the rigidity of the foamed composite is reduced.

Next, as in the invention of claim 6, the thermoplastic elastomer is preferably styrene-butadiene-styrene (SBS) or styrene-ethylene-butadiene-styrene (SEBS). In this case, a foam composite having good compatibility and excellent appearance of the skin material can be obtained.

Next, a foam comprising a plurality of rows and a plurality of stages of a core material obtained by foaming a foamable resin for a core material, and the periphery of the foam material are integrally covered. Extrusion characterized by a skin material made of a non-foamed thermoplastic resin or a low-foamable thermoplastic resin, and wherein the plurality of rows and the plurality of stages of the core material are fused together at adjacent portions. There are foam composites.

In this case, each core material has a uniform foaming property and a skin material integrally covers the core material. The core material has good uniformity of foam cells, good closed cells and high expansion ratio. In addition, a lightweight, highly rigid foam composite can be provided.
Such an extruded foam composite can be obtained by the above production method.

Next, as in the invention of claim 8, the thickness of the skin material is preferably 0.1 to 25% of the thickness of the foam formed of the core material in a plurality of rows and a plurality of stages. . In this case, the effects of being particularly light, having high rigidity, and low cost can be obtained. When the thickness is less than 0.1%, the rigidity of the foamed composite is reduced. On the other hand, when the thickness is more than 25%, the rigidity is improved, but there is a problem that the composite becomes heavy and the cost increases.

Next, as in the ninth aspect of the present invention, it is preferable that each core material has a skin layer made of the foamable resin for the core material on its surface, and the skin layers are fused to each other. . In this case, since each core material is covered by the skin layer and the skin layers are fused to each other, the rigidity of the extruded foam composite is particularly increased. Preferably, the thickness of the skin layer is 0.1 to 20 μm. 0.1
If it is less than μm, the effect of improving rigidity is low, while if it exceeds 20 μm, the skin layers may not be sufficiently fused to each other.

Next, as in the tenth aspect of the present invention, it is preferable that the core material is a polystyrene resin and the skin material is a styrene thermoplastic resin. In this case, a foam composite having high rigidity can be obtained, and a relatively inexpensive foam composite can be obtained because the polystyrene resin is a general-purpose resin.

Next, as in the eleventh aspect of the present invention, the skin material comprises a main component comprising 70 to 30% by weight of a styrene-based thermoplastic resin and 30 to 70% by weight of an olefin-based thermoplastic resin. It is preferable to mix 1 to 7% by weight of a thermoplastic elastomer with respect to 100% by weight. In this case, the same effects as those of the fifth aspect can be obtained.

Next, it is preferable that the thermoplastic elastomer is styrene-butadiene-styrene (SBS) or styrene-ethylene-butadiene-styrene (SEBS). In this case, the same effect as the above-described claim 6 can be obtained.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 An extruded foam composite and a method for producing the same according to an embodiment of the present invention will be described with reference to FIGS. First,
As shown in FIG. 5, the foam composite 5 to be obtained in this example has a plurality of rows and a plurality of rows of foamed resin for the core material, that is, five rows and two steps of the core material 100, and It comprises a skin material 30 made of a non-foamed thermoplastic resin or a low-foamable thermoplastic resin whose periphery is integrally coated.

The core material 100 having a plurality of rows and a plurality of stages is provided.
The skin layer 15 of the adjacent portion is fused to each other. That is, each core material 100 is composed of a large number of expanded particles 101, and the periphery thereof is surrounded by the skin layer 15. The skin layers 15 are fused to each other. As a result, a foam 10 in which a plurality of rows and a plurality of stages of a core material are integrated
4 are formed. The above-mentioned skin layer 15 is formed when it is discharged from a nozzle during molding.

Next, as shown in FIGS. 1 and 4, a foaming resin 10 for a core material made of a thermoplastic resin containing a foaming agent is first extruded. While extruding from the first die 2 of the machine 1, the skin material 30 made of non-foamed thermoplastic resin or low-foamable thermoplastic resin
Extrude from the second die 33 of the extruder 3. Then, the first die 2 and the second die 3 provided at the tip of both extruders.
Outside the core 3, a foam composite 5 is formed by covering the outer periphery of the core material 100 made of the foamable resin for the core material with the skin material 30.

From the first die 2, the core resin 100 is extruded and foamed from the nozzles 25 arranged in a plurality of rows and a plurality of stages to form the core material 100. From the second die 33 to the skin material 30
Is pushed out of the core material 100 in a plurality of rows and a plurality of stages, and the surface material 30 is immediately led to the cooling sizing 4. At this time, the skin material 30 is pressed against the inner surface of the cooling sizing 4 by the foaming force of the foaming resin for the core material, and a plurality of rows and a plurality of stages of cores formed by the foaming resin for the core material are formed. The skin material 30 is coated on the outer surface of the foam 104 made of the material 5.

Hereinafter, these will be described in detail. First, a foam molding apparatus for performing the above extrusion foam molding is shown in FIGS.
As shown in FIG. 4, the foaming resin 1 for the core material is placed on the first die 2.
And a second extruder 3 for feeding the skin material 30 to the second die 33. On the downstream side of the first die 2, cooling sizing 4, cooling water tank 4
5, a take-up machine 46 is sequentially arranged (FIG. 4).

As shown in FIGS. 1 to 3, the first die 2 extrudes the core foaming resin 10, ten nozzles 25, and a guide for guiding the core foaming resin 10 to the nozzles 25. And a part 24. Between the guide parts 24,
A manifold 23 for partitioning these is provided. As shown in FIG. 1 and FIG.
Is provided with a slit 28 for forming a skin material, which is an annular rectangular shape as a skin material outlet so as to surround them.

The second extruder 3 has a flow path 32 for guiding the skin material 30 to the slit 28. In addition, as shown in FIG. 3, the first die 2 is
Is inserted into the mounting hole 35 of the second die 33. Thus, the slit 28 is formed between the first die 2 and the second die 33.

The temperature of the foaming resin 10 for the core material in the first die 2 is set between the first die 2 and the second die 33 of the second extruder 3.
It has a chamber 22 as a heat insulating mechanism for adjusting the temperature to be lower than the temperature of 0 by 20 ° C. or more.
The chamber 22 has a heat medium flow path structure in which the heat medium flows.

Next, the manufacturing method will be described in detail with reference to FIGS. The core expandable resin 10 extruded from the first extruder 1 is guided to the first die 2 through a joint 11 connecting the first extruder 1 and the first die 2. First
The space 21 of the die 2 is a coat hanger-shaped portion for uniformly spreading the molten resin in the width direction, and the center portion has a narrower resin passage gap than the outer peripheral portion. The foaming resin 10 for the core material flows into the rear manifold 23, is made more uniform, is guided to the nozzles 25, and finally becomes the first die 2.
Is extruded out of the die from the nozzle 25 provided at the tip of the nozzle and foams.

On the other hand, the skin material 30 is extruded from the second die 33 of the second extruder 3, is spread in the width direction in the flow path 32, and is uniformly distributed on both upper and lower sides, and the outlet of the first die 2. It is led to. The exit of the first die 2 is the slit 28
The thickness of the skin material 30 is adjusted to 25% or less of the core material thickness by the screw rotation speed of the second extruder 3.

The foaming resin 10 for the core material extruded from the nozzles 25 in a plurality of rows and a plurality of stages is foamed there to become a total of ten core materials 100. These core materials 1
The 00 skin layers 15 are fused together. Then, a molded product in which the skin material 30 covers the outer periphery of the foam body 104 including the ten core materials 100 is obtained.

At this time, the skin material 30 is pressed against the inner surface of the cooling material of the cooling sizing 4 by the foaming force of the core material 10. Then, the skin material 30 and the foam 10
4 is fused to the outer peripheral surface. The foaming of the foaming resin 10 for the core material is performed in the skin material 30 in the shape of a rectangular box formed by the slit 28. This molded product is taken off by a caterpillar type take-up machine 46 through a cooling water tank 45 inside the cooling sizing 4.

As described above, as shown in FIG. 5, a foam 104 formed by fusing a plurality of rows and a plurality of stages of ten core materials 100 and a skin material 30 integrally covering the periphery thereof. The foam composite 5 is obtained. And each core material 10
No. 0 has a skin layer 15 on the outer periphery thereof, and adjacent portions of the skin layer 15 are fused to each other.

Small diamond-shaped, semi-diamond-shaped, triangular or square gaps 16 are formed between the adjacent skin layers 15 and between the skin layer 15 and the skin material 30 (FIG. 5). . When the extruded foam composite is formed as described above, each of the cores 100 expands, and the gap 16
When the distance between them becomes smaller, the gas remaining in the gap between them becomes smoother to the rear side, that is, to the first die 2 side, or the gas discharge path to the front side. Play a role. As a result, the core material 100 is smoothly foamed, and a uniformly foamed core material is obtained.

In this example, the foaming resin 10 for the core material extruded in a plurality of rows and a plurality of steps is foamed at the outlet of the first die 2, and the foamed resin 10 for the plurality of rows and the plurality of steps is obtained from the foamed core material 100. The skin material 30 is coated around the foam body 100. Therefore, the foam cells in the core material 100 become uniform, and a high-magnification foam can be obtained without closing cells, that is, without breaking the foam cell film.

If the skin material 30 is merged around the core foaming resin 10 in the first die, the core foaming resin is covered with the skin material, or the core foaming is performed in the first die. When the skin material 30 is covered in the first die by foaming the conductive resin, the above effects cannot be obtained.

Further, between the first die exit surface 20 provided with the nozzle 25 and the slit 28 which is the exit of the skin material,
An annular rectangular gap 361 is set (FIG. 2). Therefore, a core material having a high expansion ratio of, for example, 7 to 50 times can be obtained.

The surface of the foam 104 made of the excellent core material 100 is covered with the skin material 30 almost simultaneously with the foaming of the core material. Therefore, the skin material 30 and the foam 1
The effect that the fusion with the core material 04 and the fusion of the core materials 100 can be surely performed can be obtained. The core material extruded and foamed from each nozzle is formed in a plurality of rows and a plurality of stages, and is fused with the core material 100 adjacent to each other. Therefore, the rigidity of the extruded foam composite 5 is also improved. Further, the extruded foam composite 5 is lightweight because it is composed of the foam and the skin material.

Embodiment 2 Next, specific examples and comparative examples of the present invention will be described. Acrylic butadiene styrene (ABS) resin was used as the skin material.
A full-flight screw with L / D = 24 and compression ratio = 2.4 was used.
80-190-200-200 ° C, the second die is 2
The temperature was set to 00 ° C. The screw rotation speed was 30 RPM.
The temperature of the resin at the exit of the second die was 200 ° C.

As the foaming resin for the core material, a polystyrene resin impregnated with 7% by weight of butane as a foaming agent was used. Also, 1.2 wt% of talc was mixed as a nucleating agent with 100 wt% of polystyrene resin. The second extruder
A full-flight screw having a diameter of 45 mm, L / D = 20, and a compression ratio of 2.4 was used. The temperature of the cylinder was 110-120-120 ° C. from the hopper side, and the die head was 130 ° C. The temperature of the heat medium in the adiabatic chamber was set at 130 ° C. and circulated by a pump. The screw rotation speed was 35 RPM. The temperature of the foamable resin at the exit of the die was 120 ° C.

The temperature of the skin material at the exit of the second die is 1
The temperature of the foamable resin for the core material was 125 ° C.
The temperature difference (ΔT) between the skin material and the foamable resin for the core material was 70 ° C. The shape of the slit that extrudes the skin material is 18 inside.
A rectangular slit having a size of 193 mm × 20 mm × 195 mm outside was formed, and the gap between the slits was 1 mm.
The shape of the second die for foaming resin for core material is 35m in length.
A nozzle having a diameter of 2.5 mm was arranged at a gap of 21.5 mm at the center in the vertical direction having a size of 187 mm in width, and both ends were set to 7.5 mm.

The shape of the cooling plate in the cooling sizing was box-shaped with a length of 50 mm and a width of 200 mm, the shape was split vertically from the middle part, the temperature was 30 ° C., and the foam composite was cooled. Molding was performed at a take-up speed of 1 m / min.

The foamed composite obtained had an extremely good appearance, the average thickness of the skin material 30 was 1.0 mm, and the core material 100
Had a uniform foaming state and an average expansion ratio of 15 times. Further, the skin material 30 and the outer peripheral surface of the foam 104 are fused together,
The fusion between the 0 core material coatings 15 was also sufficient. The skin layer 15 had a thickness of 1 to 20 μm.

Embodiment 3 As the skin material, a resin containing 60 wt% of polypropylene resin and 40 wt% of talc as a filler was used, and the temperature of the cylinder was 190-200-21 from the hopper side.
The temperature was 0 to 210 ° C, and the temperature of the second die was 210 ° C. First
The temperature of the skin material at the exit of the die was 200 ° C, and the temperature of the foamable resin for the core material was 125 ° C. Resin temperature difference (Δ
T) was 75 ° C. The average foaming ratio of the core material was 15 times, and the foamed state was uniform. Although the skin and the core material were dissimilar materials, the fusion was insufficient, but the fusion between the core layers was sufficient, and the rigidity of the foam composite was sufficiently high. Other than that, it was the same as the second embodiment.

Fourth Embodiment As shown in FIG. 6, this embodiment shows an example in which the ribs 305 are provided so as to divide the core material 100 into three rows and two rows at right and left sides. The rib 305 is positioned at 1 in the thickness direction of the foam composite 5.
The material and thickness are the same as those of the skin material 30.

In forming the extruded foam composite 5, an extrusion port for forming the rib 305 is provided in the die. Extruded foam composite 5 obtained according to this example
Has the ribs 305, and thus has high strength. Other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment can be obtained.

Embodiment 5 As shown in FIG. 7, this embodiment is an extruded foam composite 5 in which a foam 104 composed of a core material 100 having six rows and three stages is covered with a skin material 30. Others are the same as the first embodiment.

Embodiment 6 In this embodiment, as shown in FIG. 8, an extruded foam composite 5 having a concave portion 58 on the left and a convex portion 59 on the right is shown. The extruded foam composite 5 includes a foam 104 composed of a core material 100 having a plurality of rows and a plurality of stages, and a skin material 30 covering the surface thereof. The extruded foam composite 5 is used as a panel material to be fitted and fitted to the recess 58 in the left-right direction in FIG. Other configurations are the same as those of the first embodiment.

Embodiment 7 This embodiment is an extruded foam composite 5 having a two-stage core material 100 as shown in FIG. The upper six core members 100 and the lower core members 100 are in a state where the centers thereof are shifted by half each. Others are the same as the first embodiment.

Eighth Embodiment As shown in FIG. 10, this embodiment is an extruded foam composite 5 having an upper and lower two-stage core material 100. The lower core material 100 is half the thickness of the upper core material 100. Further, the lower one core has a width 1.5 times that of the upper core. Others are the same as the first embodiment.

Embodiment 9 As shown in FIG. 11, this embodiment shows various nozzle shapes provided in the first die. (A) of FIG.
(B) is a square 61 having arc portions 611 at four corners, (C).
Is a cross shape 62 whose top 621 is semicircular, (D) is a square 63 having protruding arc portions 631 at four corners, (E) is a rectangle 63 having protruding arc portions 631 at two corners, and (F) is a The square 63 (G) having the protruding arc portion 631 is an elongated rectangle 64.

These various nozzle shapes are appropriately selected according to the desired cross-sectional shape of the core material. For example, (A),
In the case of the nozzle shape of (B), it is preferable to use it for a nozzle for extruding a core material located inside the foamed composite. When the foaming ratio is low and the gap 16 between the core materials (see FIG. 5) is large, the nozzles (C) and (D) are preferable. In this case, the extruded foam part from the top part 621 and the protruding arc part 631 fills a part or all of the space between the gaps 16. Therefore, a uniform foam composite having a small gap 16 can be obtained.

Further, for (E) and (F), a multi-column
It is preferable as a nozzle for extruding a core material located at a corner portion among a multi-stage core material. In this case, the gap between the corner portion of the foamed composite and the skin material can be filled with the extruded foamed portion from the protruding arc portion 631, and the rigidity of the corner portion can be increased. The above (A) to (G) are representative examples, and the present invention is not limited thereto.

[0072]

According to the present invention, there is provided an extruded foam composite having good uniformity of foam cells, good closed cells, a core material having a high expansion ratio, light weight and high rigidity, and a method for producing the same. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional explanatory view of a foaming composite molding apparatus according to a first embodiment.

FIG. 2 is an explanatory view of a tip portion of a first die of the foam composite molding apparatus according to the first embodiment.

FIG. 3 is an explanatory view of a state in which a first die is assembled to a second extruder of the foam composite molding apparatus according to the first embodiment.

FIG. 4 is an overall plan view of an apparatus for molding a foamed composite according to the first embodiment.

FIG. 5 is a cross-sectional perspective view of the foam composite obtained in the first embodiment.

FIG. 6 is a cross-sectional perspective view of a foam composite obtained in a fourth embodiment.

FIG. 7 is a cross-sectional perspective view of a foam composite obtained in a fifth embodiment.

FIG. 8 is a sectional perspective view of a foam composite obtained in a sixth embodiment.

FIG. 9 is a cross-sectional perspective view of a foam composite obtained in a seventh embodiment.

FIG. 10 is a cross-sectional perspective view of a foam composite obtained in an eighth embodiment.

FIG. 11 is an explanatory view of various cross-sectional shapes of a nozzle of a first die in a ninth embodiment.

[Explanation of symbols]

 1. . First extruder, 10 . . 100. foamable resin for core material; . . Core material, 104. . . Foam, 2. . . First die, 25. . . Nozzle, 3. . . Second extruder, 30. . . Skin material, 305. . . Ribs, 5. . . Foam composite,

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tadashi Hattori 1000 Kawajiri-cho, Yokkaichi-shi, Mie F-term in Mitsubishi Chemical BSF Ltd. (reference) 4F207 AA03 AA13 AA45 AA46 AB02 AG01 AG03 AG20 AH43 AH46 AR06 KA01 KA11 KB22 KK76 KL58 KL65

Claims (12)

[Claims] 1. A foaming resin for a core material comprising a thermoplastic resin containing a foaming agent is extruded from a first die of a first extruder, while a skin comprising a non-foaming thermoplastic resin or a low foaming thermoplastic resin. The material is extruded from the second die of the second extruder, and the outer skin material is formed on the outer periphery of the core material made of the foamable resin for the core outside the first die and the second die provided at the tip of both extruders. A foamed composite formed by coating the foamed resin for the core material by extruding and foaming the foamable resin for the core material from the first die through nozzles arranged in a plurality of rows and a plurality of stages. While forming the material, the surface material is extruded from the second die to the outside of the core material, and the surface material is immediately led to cooling sizing, and the surface material is formed by the foaming force of the foamable resin for the core material. Inside of the above cooling sizing To produce an extruded foam composite formed by covering the outer surface of a foam comprising a plurality of rows and a plurality of stages of a core material formed of the foamable resin for a core material with the skin material. A method for producing an extruded foam composite. 2. The method according to claim 1, wherein the first die comprises:
The temperature of the foaming resin for the core material in the first die is lower than the temperature of the skin material by two times between the second extruder and the second die.
A method for producing an extruded foam composite, comprising a heat insulating mechanism for adjusting the temperature to a temperature lower than 0 ° C. 3. The foaming resin for core material according to claim 1, wherein the foamable resin for the core material is extruded from a plurality of rows and a plurality of rows of nozzles provided in the first die and having an opening area of one nozzle of 30 mm ² or less. And a foaming ratio of 7 to 50 times. 4. The method according to claim 1, wherein:
The foamable resin for the core material is a polystyrene resin 75 to 9
7.8% by weight, foaming agent 2 to 20% by weight, nucleating agent 0.2 to 5
% By weight, wherein the skin material is a styrene-based thermoplastic resin. 5. The method according to claim 1, wherein:
The above skin material is 70 to 30% by weight of a styrene thermoplastic resin.
And an olefinic thermoplastic resin in an amount of from 30 to 70% by weight, and a thermoplastic elastomer in an amount of from 1 to 7% by weight based on 100% by weight of the main component. Production method. 6. The thermoplastic elastomer according to claim 5, wherein the thermoplastic elastomer is styrene-butadiene-styrene (SBS).
Or styrene-ethylene-butadiene-styrene (SE
(BS). 7. A foam comprising a plurality of rows and a plurality of stages of a core material obtained by foaming a foamable resin for a core material, and a non-foamed thermoplastic resin or a non-foamed thermoplastic resin integrally covering the periphery of the foam material. An extruded foam composite comprising a skin material made of an expandable thermoplastic resin, and wherein the plurality of rows and the plurality of stages of the core material are fused to each other at adjacent portions thereof. 8. The extruded foam composite according to claim 7, wherein the thickness of the skin material is 0.1 to 25% of the thickness of the foam comprising a plurality of rows and a plurality of stages of the core material. body. 9. The extrusion method according to claim 7, wherein each core material has a skin layer made of the foamable resin for the core material on a surface thereof, and the skin layers are fused to each other. Foam composite. 10. The extruded foam composite according to claim 7, wherein the core material is a polystyrene resin, and the skin material is a styrene thermoplastic resin. 11. The skin material according to claim 7, wherein the skin material comprises a main component comprising 70 to 30% by weight of a styrene-based thermoplastic resin and 30 to 70% by weight of an olefin-based thermoplastic resin. An extruded foam composite comprising 1 to 7% by weight of a thermoplastic elastomer with respect to 100% by weight of a main component. 12. The method according to claim 11, wherein the thermoplastic elastomer is styrene-butadiene-styrene (SB).
S) or styrene-ethylene-butadiene-styrene (SEBS).