JPH0124619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for producing a synthetic resin foam laminate.

A synthetic resin foam laminate is a laminate made of synthetic resin, at least one layer of which is made of synthetic resin foam. Among synthetic resin foam laminates, those with a foamed synthetic resin layer in the center and non-foamed synthetic resin layers on both sides have already been used for various purposes as lightweight bodies with high surface hardness. ing. On the other hand, products with a non-foamed synthetic resin layer sandwiched in the center and foamed synthetic resin layers on both sides, especially those with thick foamed layers, have not been used much until now. I couldn't help it.

The inventor noticed that a laminate containing a non-foamed layer sandwiched between thick foamed layers on both sides may be particularly useful.
In other words, such a laminate has the appearance of a foam but is reinforced by the non-foamed layer located inside, and if the appropriate resin is selected, the non-foamed layer will prevent gas and liquid from flowing. It has been found that this can be useful in some applications because the permeability is blocked. Therefore, we attempted to manufacture such a laminate.

PRIOR ART It is already known to produce synthetic resin foam laminates by extrusion. For example,
It is described in Japanese Patent Publication No.-37752 and Japanese Patent Publication No. 49-44114. However, the methods described in these publications are not suitable for producing thick laminates. This is because these publications require the resin to be extruded as a tube through an annular extrusion hole.
This is because if this was cut open to form a laminate, the resulting laminate would warp due to its resilience and could not be used as a flat plate.

On the other hand, when a non-foamed resin is used, it is known to extrude it in the form of a flat plate to produce a synthetic resin laminate. It is described, for example, in Japanese Patent Publication No. 46-28310 and Japanese Patent Publication No. 49-39501.
This method uses at least two extruders, each extruder is equipped with a nozzle equipped with a flat extrusion hole, and one of the extruders is large, and the remaining nozzles are accommodated in the nozzle. This is a method in which the flat holes are oriented parallel to each other and fixed, and the resin extruded from the remaining nozzles is wrapped with the resin extruded from the first nozzle to form a laminate.

Problems to be Solved by the Invention The inventor directly applied the above laminate production method proposed for non-foamed resins to foams, but a good laminate could not be obtained. That is, a foamed laminate with non-foamed resin sandwiched therein was produced by supplying foamed resin into the large nozzle and supplying non-foamed resin to the internal nozzle fixed within the large nozzle. The non-foamed resin was deformed and distorted due to the volume expansion of the foam, and as a result, a foam that could be called a laminate could not be obtained. Therefore, the inventor conducted further research.

When manufacturing foam molded products by extrusion method,
It is already known that a cylindrical molded body is attached to the tip of the nozzle, the foamable resin is immediately extruded from the nozzle into the cylindrical molded body, and the resin is foamed while adjusting the shape within the cylindrical molded body. There is. However, it is not known that the provision of such a cylindrical molded body is useful for preventing deformation and distortion of the non-foamed resin contained in the laminate. The inventor has confirmed that by attaching such a mold to the tip of a large die, deformation and distortion of the non-foamed resin layer in the laminate can be prevented. At the same time, the inventor confirmed that it is necessary to appropriately cool the foamable resin at the tip of the large cap. This invention was completed based on such confirmation.

Means for Solving the Problem This invention uses at least two extruders, each extruder is provided with a die having a flat hole for extrusion, and the resin passage of one of the large die is In the method of accommodating the remaining cap and fixing it with the flat holes oriented in parallel, the resin extruded from the remaining cap is sandwiched between the resin extruded from the larger cap and extruded as a laminate. Supplying a synthetic resin containing a foaming agent into the mouthpiece, supplying a non-foaming resin or another resin into the rest of the mouthpiece, cooling the resin passage wall at the tip of the large mouthpiece,
The present invention relates to a method for manufacturing a synthetic resin foam laminate, which comprises attaching a mold to the tip of a large die, extruding the laminate from the die into the mold, and foaming the resin within the mold.

The present invention will be explained as follows based on the drawings. FIG. 1 is a longitudinal sectional view of the apparatus while practicing the invention, and FIG. 2 is a horizontal sectional view of the same apparatus. To be more specific, Figure 1 corresponds to a cross-sectional view taken along the - line in Figure 2;
The figure corresponds to a sectional view taken along the - line in FIG.
Figure 3 is an enlarged view of a portion of Figure 1;
6 through 6 are partially cut away longitudinal sectional views of other devices used in the present invention. 7 and 8 are partially cutaway perspective views of a foamed laminate obtained by the present invention.

In Figures 1 and 2, 1 is the main extruder, 2
is a screw, 3 is a sub-extruder, 4 is a screw,
5 is a large die, 6 is a small die, 7 is a mold, and 8 is a second die.
The passage, 9 is a take-up machine, and 10 to 12 are fluid passages. Further, a is a foaming agent-containing resin, b is a non-foaming resin, and c is a resin foam laminate.

In this invention method, two extruders are used, namely a main extruder 1 and a sub-extruder 3.
A large mouthpiece 5 is attached to the auxiliary extruder 3, and a small mouthpiece 6 is attached to the sub-extruder 3. The small cap 6 is housed within the large cap 5. The small die 6 and the large die 5 are provided with flat extrusion holes 61 and 51, respectively,
The flat holes are oriented parallel to each other. A mold 7 that surrounds the flat hole 51 of the large mouthpiece 5 is tightly fitted around it. Further, a fluid passage 10 is provided around the flat hole 51 at the tip of the large mouthpiece 5, and by circulating a cooling medium within the passage 10, the resin passage wall is cooled. .

In the apparatus shown in FIGS. 1 and 2, the relationship between the large die 5, the small die 6, and the mold 7 is shown in FIG. 3 in an enlarged manner. The small mouthpiece 6 is positioned parallel to the flat extrusion hole 51 of the large mouthpiece 5 so that the resin extruded from the flat hole 61 passes through the middle of the flat hole 51. It is fixed within 5. The small cap 6 is fixed using the second
This is done by fixing both ends 63 and 64 of the flat hole 61 in the small cap 6 to the large cap 5 as shown in the figure.

In this invention method, a synthetic resin a containing a foaming agent is supplied from a main extruder 1 into a large nozzle 5, and a non-foaming resin b containing no foaming agent is supplied from a sub-extruder 3 into a small nozzle 6. do. Then, the non-foamable resin b is
It is extruded from the flat hole 61 of the small mouthpiece 6 into the foamable resin a in the large mouthpiece 5. The extruded non-foamable resin b is sandwiched between the foamable resins and advances through the large mouthpiece 5, and the flat hole 51 forms a laminate in which the non-foamable resin b is sandwiched by the foamable resin a. and extruded into a mold 7. In this way, the laminate is formed into the mold 7
The material is foamed inside to form a foamed laminate c.

In the above method, when the mold 7 is not used, the cross-sectional outline of the laminate c will not be constant. Therefore, it is not possible to obtain a foam having a desired cross section. Furthermore, even if the mold 7 is used, if the mold 7 is placed apart from the base 5, it will be difficult to make the outer shape of the foamed body constant. Therefore, it is desirable that the mold 7 be placed as close to the base 5 as possible. In particular, it is desirable to bring the mold 7 into close contact with the tip of the base 5 so that the resin from the base 5 is directly extruded into the mold 7.

A fluid passage 10 is provided around the flat hole 51 of the large mouthpiece 5.
However, in the above method, when the cooling medium is not circulated within the fluid passage 10,
The non-foamed resin layer b bends within the foamed resin layer a and changes its position greatly, and sometimes the non-foamed resin layer b is torn, making it impossible to obtain a well-ordered foam laminate in the shape of a sanderch. However, when a cooling medium is circulated within the fluid passage 10 and the resin passage at the tip of the large mouthpiece 5 is appropriately cooled, the non-foaming resin b is placed in an orderly manner at a fixed position within the foaming resin a. A laminate c is obtained in which unfoamed resin is sandwiched between foamed resin a as flat plates.

As the cooling medium to be circulated through the fluid passage 10, oil, water, air, etc. can be used. The cooling medium is
Since the purpose is to cool the tip of the cap which is at a high temperature, more specifically, the wall of the resin passage at the tip of the cap, a material with a fairly high temperature is used. The cooling medium is
The temperature is set to be at least 5 degrees Celsius or more, preferably 30 to 60 degrees Celsius lower than the resin temperature at the entrance of the flat hole 51 of the large mouthpiece 5.

The mold 7 restricts the cross-sectional shape of the resin passing through it from all sides, and has a cylindrical shape. Its inner surface is coated with fluororesin 71 to make the resin slippery. Further, in order to cool the inner surface thereof, a fluid passage 11 is bored in the wall, and a cooling medium is circulated through the passage 11.

The cross section of the resin passage in the mold 7 is not the same throughout. That is, at the end close to the base 5,
Although the passage has almost the same shape and size as the flat hole 51 of the cap 5, it immediately widens rapidly in the thickness direction and simultaneously widens in the width direction. Thereafter, the passageway does not widen significantly in either the thickness direction or the width direction, but expands slightly or continues with almost the same thickness or width. The mold 7 has fluid passages 11 within its walls.
is attached to cool the wall surface.

In this invention, the resin extruded from the die enters the mold 7 in a layered state, and the foamable resin portion foams mainly in the thickness direction while being regulated from all sides. It is then cooled to form a foamed laminate.

The second passage 8 is provided at a distance from the mold 7, and a gap 13 is formed therebetween. The second passage 8 is composed only of upper and lower plates for regulating the flat surface. That is, although there is a wall surface in the thickness direction, there is no wall surface in the width direction, so that it is in an open state. The distance between the wall surfaces in the thickness direction becomes gradually narrower or equal in the direction in which the resin travels. The distance between the wall surfaces on the entrance side of the second passage 8 is larger than the distance between the wall surfaces on the exit side of the mold 7. Further, the distance between the wall surfaces on the exit side of the second passage 8 is close to the thickness of the laminate to be obtained. Further, a fluid passage 12 is provided in the wall surface to cool the stacked body. In this way, the laminate c that has exited the second passage 8 is taken up by the take-up machine 9.

The present invention is not limited to the case where the small cap 6 is completely housed within the large cap 5 as shown in FIG. For example, as shown in FIG. 4, the tip of the small cap 6 may be located side by side with the tip of the large cap 5, or as shown in FIG. It may protrude from the tip of 5.

In the case of FIG. 3, the resins extruded from the nozzles 5 and 6 are layered on each other at a relatively early stage, so
Provides strong adhesion. In addition, in this case, since the resins are laminated when they are all at a high temperature, even if a non-foaming resin that does not contain a foaming agent is extruded from the nozzle 6, the foaming agent in the foaming resin becomes the non-foaming resin. The resins migrate and thus also foam without foaming agents to a certain extent, which may further increase the adhesion. Therefore, the case shown in FIG. 3 is effective for laminating resins whose mutual adhesion is not very good.

In the case of Fig. 4, the foamable resin starts foaming at the same time as the resin extruded from the nozzles 5 and 6 is laminated, so if the temperatures of the extruded resins are close to each other, the resin can be foamed at a high magnification. Effective for obtaining laminated products.

In the case of Fig. 5, when the resin extruded from the nozzle 6 is not desired to be foamed, or the foamable resin extruded from the nozzle 5 is foamed at a low magnification, a laminate with a thick skin layer is obtained. This is useful when trying to

Further, according to the present invention, as shown in FIG. 6, two small caps 66 and 67 can be housed in parallel in the cap 5 to create a laminate consisting of five layers.

Further, as the resin extruded from the nozzle 6, a foamable resin different from the resin extruded from the nozzle 5 may be used in addition to a non-foamed resin.

When using the apparatus shown in FIGS. 1 to 5, for example, as shown in FIG. 7, a foamed resin layer a sandwiches a non-foamed resin layer b, and a skin layer d with a slight thickness is formed on the surface. A foamed laminate c is obtained.
Further, when using the apparatus shown in FIG. 6, for example, as shown in FIG. 8, three foamed resin layers a
Two non-foamed resin layers b are sandwiched between them,
A laminate having a slightly thick skin layer d on the surface is obtained.

Effects of the Invention According to the method of the invention, at least two extruders are used, each extruder is provided with a die having a flat hole for extrusion, and one of the large die is provided with a resin passage. The remaining nozzles are accommodated, the flat holes are fixed in parallel to each other, and the resin extruded from the accommodated nozzles is sandwiched between the resin extruded from the larger nozzle and extruded as a laminate, so one extrusion is enough. A laminate can be made. Moreover, since the resin containing the foaming agent is supplied into the large nozzle and the non-foamed resin or another resin is supplied into the remaining nozzle, a foamed laminate with non-foamed or another resin sandwiched therein can be obtained. can be made all at once. Furthermore, since the resin passage wall is cooled at the tip of the large mouthpiece, the foamable resin flows smoothly within the passage and therefore does not undergo any undesirable deformation. On top of that, a mold is attached to the tip of the large nozzle, and the laminate is extruded from the nozzle into the mold and foamed within the mold, which prevents the foamable resin from being distorted during foaming. Therefore, there is no deformation of the resin layers sandwiched therein, and a good laminate can be obtained. The inventive method provides these advantages.

As the synthetic resin used in this invention, any synthetic resin can be used as long as it is a thermoplastic resin. Among these, a laminate obtained by using expandable polystyrene as the resin extruded from a large die and olefin resin as the resin extruded from the remaining die has a higher transparency than a foam board made only of polystyrene. Humidity resistance is extremely high,
It is particularly useful as a functional insulation material because it is resistant to bending and impact.

EXAMPLES Next, details of the present invention will be explained with reference to examples.

Example 1 In this example, it was attempted to obtain a foam laminate as shown in FIG.

First, two extruders were arranged as shown in FIGS. 1 and 2, and the first extruder (diameter 50 mm) was used to produce a polystyrene foam board. 1st
The resin used in the extruder is polystyrene.
A mixture of 100 parts by weight (hereinafter simply referred to as parts), 2 parts of hexabromocyclododecane (flame retardant), 1 part of finely powdered talc (bubble control agent), and a small amount of colorant was used, and dichlorodifluoromethane was used as a blowing agent. and methyl chloride in a weight ratio of 1:1, and a blowing agent was mixed in the extruder at a ratio of 10 parts to 100 parts of the resin.

The second extruder (diameter 32 mm) was filled with high-pressure polyethylene and ethylene vinyl acetate copolymer resin by weight of 7.
A mixture of 1:3 and 3:3 was used, and this copolymer resin contained 1 part of Cellmic CAP500 as a blowing agent per 100 parts of the copolymer resin. This resin mixture is heated to 130℃ from the base 6.
It was pushed out. The cap 6 has a thickness of 0.3 mm, a width of 90 mm,
It was equipped with a flat extrusion hole with a length of 5 mm.

The cap shown in FIG. 5 was used. The dimensions of each part are as follows. The thickness of the foamed resin passage in the cap 5 is 22 mm and the width is 150 mm.
A cap 6 with a thickness of 12 mm was attached therein. Passages 54 and 55 where the foamable resin is separated
had a thickness of 0.8 mm, a width of 100 mm, and a length of 10 mm. The die 6 was equipped with a flat hole for extrusion having a thickness of 0.3 mm, a width of 0.9 mm, and a length of 5 mm.

The mold 7 has a thickness of 18 mm and a width of 140 mm at the exit.
The length was 100mm.

The resin from the second extruder is extruded from the nozzle 6 at 130°C, and the resin from the first extruder is extruded from the nozzle 5, and water at 70°C is circulated through the fluid passage 10 of the extrusion nozzle 5 to form a foamable resin. While cooling the surface of the resin, the laminated resin is extruded into the mold 7, foamed in the mold 7, passed through the second passage 8, and passed through the second passage 8 into a mold with a thickness of 25 mm, width of 200 mm, and density of 42 kg/ A foam laminate with a skin layer of m ³ was obtained.

Since this foamed laminate sandwiched the above-mentioned polyethylene resin film in between, it had significantly higher moisture permeation resistance than a foamed board made only of polystyrene.

Example 2 In this example, a foam laminate with a non-foamed polystyrene sheet in the middle was obtained using a die as shown in FIG. 3. The details are as follows.

The flat extrusion hole of the die 5 had a thickness of 22 mm and a width of 150 mm, and a die 6 with a thickness of 16 mm was built therein. The divided resin passages 52 and 53 each had a thickness of 3 mm, a width of 150 mm, and a length of 5 mm. The mold 7 used had a length of 100 mm, a thickness of 18 mm at its exit, and a width of 170 mm. The foamable resin supplied to the cap 5 was the same as in Example 1.

The die 6 was fixed at a position where the tip of the flat extrusion hole 61 was 50 mm deep from the tip of the flat hole of the die 5. The flat hole 61 has a thickness of 0.5 mm, a width of 140 mm, and a length of 5 mm.
From this, non-expandable polystyrene was extruded at 140°C as a sheet with a thickness of 0.7 mm.

The resin extruded from the caps 5 and 6 in this way is
In the same manner as in Example 1, a laminate with a non-foamed polystyrene sheet sandwiched between the layers was obtained. The laminate was 25 mm thick, 220 mm wide, and had a skin layer with a density of 60 Kg/m ³ .

This foam contained a non-foamed sheet in addition to the skin layer on the surface, so it was resistant to bending and impact.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing one embodiment of the method of this invention. FIG. 3 is an enlarged partially cutaway sectional view of FIG. 1. 4 to 6 are enlarged cross-sectional views similar to FIG. 3 showing other embodiments of the method of the present invention. 7 and 8 are partially cutaway perspective views of a laminate obtained by the method of the present invention.

Claims (1)

[Claims] 1. At least two extruders are used, each extruder is provided with a die having a flat hole for extrusion, and one of the large die has a resin passageway in which the remaining resin is placed. In the method of accommodating the caps, fixing the flat holes with their flat holes oriented parallel to each other, and extruding the resin extruded from the remaining caps with the resin extruded from the larger cap to form a laminate, the resin is extruded into the large cap. A synthetic resin containing a foaming agent is supplied, a non-foamed or other resin is supplied to the rest of the nozzle, the resin passage wall is cooled at the tip of the large nozzle, and a mold is attached to the tip of the large nozzle. A method for producing a synthetic resin foam laminate, which comprises extruding the laminate from a die into a mold and foaming the resin within the mold. 2. Production of a synthetic resin foam laminate according to claim 1, wherein the foamable synthetic resin supplied to the large mouthpiece is polystyrene, and the synthetic resin supplied to the remaining mouthpieces is a polyolefin resin. Method.