JP2001121655A - Laminated synthetic resin plate and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight, large-size laminated synthetic resin plate and a method for manufacturing the resin plate efficiently. SOLUTION: A laminated synthetic resin plate in which thin plate-shaped skins are bonded integrally to both sides of a porous intermediate resin layer is produced by a process in which a molten plastic synthetic resin mixed with a filler of vegetative particles is extruded from a slit-shape discharge opening and passed between a pair of drawing rollers 32 rotating reversely to each other to form an intermediate resin layer C, the intermediate layer C is mounted on the first skin A moving longitudinally, the second skin B is laid on the layer C to overlap each other, the skins A, B are passed between lower and upper rollers 52a-52d, 53a-53d and pressed and bonded to on both sides of the molten intermediate layer C, and as required, and the bonded skins A, B are passed between a pair of press members 61, 62, which are moved to approach/ separate from each other, and cooled. The molten synthetic resin of the layer C is desirably incorporated with a foaming agent to be expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin laminate obtained by integrally bonding thin plate skins to both sides of an intermediate resin layer mixed with a filler, and to continuously form such a synthetic resin laminate. The present invention relates to a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art As a method for continuously manufacturing a synthetic resin laminate using a synthetic resin mixed with a filler, there is a technique disclosed in Japanese Patent Application Laid-Open No. 5-245962, for example, which employs a T-die. A co-extrusion molding method is used.
In this method, as a filler mixed into the synthetic resin,
There are inorganic and organic ones.

[0003]

In such a coextrusion molding method, when an inorganic filler such as talc or calcium carbonate is used as a filler to be mixed into the synthetic resin, a product such as a plate material to be molded is not used. The quality is good,
Since the specific gravity of the material is large, there is a problem that the weight of the product increases. Even when using an organic filler such as wood flour, the wood flour is finely crushed and co-extruded during co-extrusion, and the specific gravity of the material does not decrease, so the product cannot be reduced in weight and is contained in wood flour There is a problem that continuous molding by extrusion molding becomes difficult because foaming due to moisture or the like deteriorates product quality, and when the added amount of wood powder is increased, the adhesiveness of the molten resin decreases.

[0004] Extrusion molding of a large volume is difficult by the extrusion molding method, and it has not been possible to produce a synthetic resin laminate having a width x thickness of 500 mm x 20 mm or more. As a means of manufacturing a large synthetic resin laminate, a synthetic resin mixed with wood powder may be formed into a plate-like intermediate resin layer, and then a skin may be bonded to both surfaces to form a multilayer structure. It is necessary to reheat both sides of the intermediate resin layer for the adhesion of the skin,
In addition, there is a problem that production efficiency cannot be increased because continuous molding cannot be performed. An object of the present invention is to solve the above problems and to provide a lightweight and large synthetic resin laminate and a method for producing the same with high production efficiency.

[0005]

In the synthetic resin laminate according to the present invention, a thin plate-like skin is integrally formed on both sides of an intermediate resin layer made of a coarse porous synthetic resin mixed with granular plant-based pulverized products. It is characterized by being adhered to each other.

In the synthetic resin laminate according to the present invention, it is preferable that the synthetic resin constituting the intermediate resin layer is foamed by a foaming agent.

Further, according to the present invention, a method of manufacturing a synthetic resin laminate in which a thin skin is integrally bonded to both side surfaces of a porous intermediate resin layer is provided by stirring a granular synthetic resin with a rotating blade. A first step of preparing a molten synthetic resin that is made plastic by being melted by frictional heat and mixed with a granular vegetable pulverized product as a filler, and a pair of draw-out rollers that rotate the molten synthetic resin in opposite directions to each other A second step of feeding through a gap and extruding as a porous intermediate resin layer from a slit-like discharge port, and a second step on a first skin, which is made of a preformed elongated continuous thin plate and moves in the longitudinal direction.
A third step of supplying the molten intermediate resin layer extruded in the step, and an elongated continuous thin plate preformed on the intermediate resin layer placed on the first skin and moving therewith. A second step of laminating the second skins moving in the longitudinal direction, passing the plurality of lower rollers and the upper rollers, pressing the two skins onto both side surfaces of the intermediate resin layer in a molten state, and bonding the two skins together. It is characterized by the following. First
The plastic molten synthetic resin mixed with the granular plant-based pulverized product obtained in the step is agitated by a blade, so that the inside becomes porous with air thereinto. Is adhered to the outer peripheral surface of the pull-out roller and is fed through the gap between the rollers and is extruded from the discharge port, so that the internal pressure does not increase, and therefore, the porosity of the extruded molten resin layer is lost. There is no. In the third and fourth steps, both skins are pressed and adhered to both side surfaces of the intermediate resin layer in the molten state.

In the method of manufacturing a synthetic resin laminate according to the present invention, it is preferable that a large number of grooves extending in the axial direction be formed on the outer peripheral surface of the drawer roller. By doing so, the adhesion of the molten synthetic resin to the outer peripheral surface of the pull-out roller is further ensured, so that the intermediate resin layer can be reliably extruded from the discharge port.

In the method for producing a synthetic resin laminate according to the present invention, the synthetic resin laminate having both skins adhered to both sides of the molten intermediate resin layer obtained in the fourth step is forcibly cooled. It is preferable that the method further comprises a fifth step of cooling through a pair of press members which are formed and whose interval changes in a short cycle. In this way, the synthetic resin laminate having both skins A and B adhered to both sides of the intermediate resin layer is repeatedly sandwiched between the press members in a short cycle, moves in the longitudinal direction while being pressed, and cools. Is done.

In the method for producing a synthetic resin laminate according to the present invention, the granular synthetic resin mixed in the first step is mixed before and after the granular synthetic resin stirred by the rotating blade starts melting. preferable. By doing so, the granular vegetable pulverized product is not further finely pulverized by the stirring of the granular synthetic resin by the blade before melting, and the risk of carbonization is small.

In the method of manufacturing a synthetic resin laminate according to the present invention, the intermediate resin layer and the second skin B are joined to each other immediately before the second skin B is joined to the intermediate resin layer in the third step. Preferably, the surface is heated by a heater.
In this case, the bonding is performed later than the bonding between the first skin and the intermediate resin layer. Therefore, in some cases, the bonding may be insufficient compared with the first skin due to a decrease in temperature.
The bonding and adhesion between the outer skin and the intermediate resin layer are also reliably performed.

In the method for producing a synthetic resin laminate according to the present invention, it is preferable that, in the first step, a foaming agent is further mixed into the molten synthetic resin which has been melted by friction heat and made plastic. By doing so, the synthetic resin itself of the intermediate resin layer is also foamed and becomes porous.

[0013]

1 to 3 are views showing a manufacturing apparatus used in a first embodiment of a synthetic resin laminate and a method of manufacturing the synthetic resin laminate according to the present invention. This first
As shown in FIG. 3, the synthetic resin laminate according to the embodiment mainly has thin skins A,
B are integrally bonded. The intermediate resin layer C is obtained by mixing a granular synthetic resin obtained by melting a granular synthetic resin by frictional heat with a granular vegetable pulverized product, and extruding the resultant into a plate shape at a low pressure so as to be porous. Is 11mm for example
It is. The skins A and B are thin sheets of synthetic resin formed in advance by an extrusion molding method or the like, and have a thickness of, for example, 2 mm.
A grain pattern is formed on the outer surface after bonding to the intermediate resin layer C. The synthetic resin used for the skins A and B and the intermediate resin layer C may be any thermoplastic synthetic resin such as polypropylene, polyvinyl chloride, acrylonitrile / butadiene / styrene, thermoplastic / olefin, etc. Then, a mixture of a plurality of types may be used. This thermoplastic synthetic resin is not limited to an unused one, and may be a synthetic resin waste material such as a removed automobile bumper or battery case. Granular plant crushed products are kenaf core (the core of the kenaf stalk, which is an annual plant) crushed products, wood chips, and the like.
It is about 6 mm square.

First, the overall structure of the manufacturing apparatus used in the first embodiment will be described. As shown in FIG. 1, the manufacturing apparatus includes a low-pressure extruder 30, heaters 40 and 41, and a roller press, which are sequentially arranged from the left side on a floor G via first to fifth support bases 10 to 14, respectively. 50, a cooling press 60, a take-off machine 70, and a work roller table 15.
0 is provided. The skin drum Aa in which the first skin A previously formed into a thin and continuous thin plate is wound in a cylindrical shape as described above is placed on the left side of the low-pressure extruder 30, and the first skin pulled out from the lower side thereof. A is the lower support roller 1
6, extending horizontally to the right to a low pressure extruder 30;
The heater 40, the roller press 50, the cooling press 60, and the take-up device 70 extend over the work roller base 15. As described later, the intermediate resin layer C extruded and supplied from the low-pressure extruder 30 is placed on the first skin A and moves rightward with the first skin A. Further, a skin drum Ba in which a second skin B previously formed into an elongated thin plate like the first skin A is wound in a cylindrical shape is placed on the left side of the skin drum Aa, and the second is pulled out from the upper side thereof. The skin B passes over the upper support roller 17 and the guide roller 18 located above the skin drum Aa and the low-pressure extruder 30 and obliquely descends from the guide roller 18 to contact the upper side of the intermediate resin layer C. Extends horizontally to the right, low-pressure extruder 30, heater 4
0, 41, the roller press 50, the cooling press 60, and the take-up machine 70, and extend onto the work roller base 15.
The intermediate resin layer C and the skins A, B on both sides thereof are
Is moved rightward between the pair of take-off rollers 71.

Next, a method of manufacturing the synthetic resin laminate according to the first embodiment will be described together with an apparatus used therein. First, a description will be given of the first step of preparing a molten synthetic resin Ca in which a granular synthetic resin is stirred by a rotating blade and melted by frictional heat to mix a granular vegetable pulverized product as a filler. The stir-melt mixer 20 used in the first step has, for example, almost the same structure as that disclosed in Japanese Patent Application Laid-Open No. H10-151332. A plurality of protruding blades (all not shown) are provided. Granular (including chip-shaped) synthetic resin obtained by grinding synthetic resin waste material into irregular shapes with a size of about 8 mm square or less,
A predetermined amount is put into the hopper 21 of the stirring and melting mixer 20 and sent to the mixing chamber 23 by the conveyor screw,
The resin is stirred by a plurality of rotating blades and melted by frictional heat to form a plastic molten synthetic resin. The timing of the start of melting can be detected based on a change in the temperature of a part of the mixing chamber 23 or the load current of the motor 22. Immediately after the start of melting, granules (including chips) crushed into irregular shapes of about 6 mm square or less
Is fed into the hopper 21 and mixed with the molten synthetic resin in the mixing chamber 23. The input amount is, for example, kenaf core 30 with respect to synthetic resin 70 in weight ratio. When the kenaf core is uniformly mixed into the molten synthetic resin (for example, 5 seconds after the kenaf core is charged), the plastic molten synthetic resin Ca into which the kenaf core is mixed is taken out from the discharge port 24 by opening the door at the lower part of the mixing chamber 23. The molten synthetic resin Ca is fed into the supply cylinder 34 of the low-pressure extruder 30 by a conveyor (not shown).

After closing the door at the lower part of the mixing chamber 23, a predetermined amount of granular synthetic resin is again charged into the hopper 21, and the molten kenaf core is poured into the hopper 21 after it is melted in the same manner as described above. When the mixed resin is mixed with the molten synthetic resin, the door at the lower portion of the mixing chamber 23 is opened, and the mixed resin is fed into the supply cylinder 34 of the low-pressure extruder 30 through the outlet 24 and the conveyor. By repeating this, the plastic molten synthetic resin Ca mixed with the granular kenaf core pulverized product is prepared, and is sequentially fed into the supply cylinder 34 of the low-pressure extruder 30. The molten synthetic resin Ca is agitated by the blades of the agitation / melting mixer 20, and thus has a generally porous structure with air mixed therein.

Next, the molten synthetic resin Ca prepared in the first step and fed into the supply tube 34 is supplied to the slit-like discharge port 3.
The second step of extruding from Step 6 as a porous intermediate resin layer C will be described. The low-pressure extruder 30 used in the second step
The main body 31 has a rectangular frame shape as shown in FIG. 2, and a pair of horizontal and parallel pull-out rollers 32 is rotatably supported, and a motor (not shown) is used to move a facing portion downward. They are driven to rotate in opposite directions. On the outer peripheral surface of each drawer roller 32, a large number of concave grooves 32a extending in the axial direction and having a semicircular cross section are formed along the circumferential direction. The main body 31 is provided with a pair of intermediate support plates 35 forming a discharge port 36 therebetween with a slight gap between the main body 31 and the lower side of each drawer roller 32. A first outlet forming piece 36 a is fixed to the side along the discharge port 36. The second outlet forming piece 36b provided below the other intermediate support plate 35 is movable toward the discharge port 36, and is moved by an adjusting screw 38 screwed into a support fitting 37 fixed to the intermediate support plate 35. Thereby, the width of the discharge port 36 is adjusted. Body 3
A supply cylinder 34 for receiving the molten synthetic resin Ca mixed with the pulverized kenaf core product from the stirring / melting mixer 20 is provided above the mixing cylinder 1.
Are formed. Heaters 34 a and 35 a are provided on the supply cylinder 34 and the intermediate support plate 35, and a heater (not shown) is also provided on the drawer roller 32.

In the second step, the supply cylinder 3
4 is at 300 ° C, and the draw-out roller 32 is at 180-200 ° C
Meanwhile, the intermediate support plate 35 is heated to 250 ° C. The plastic molten synthetic resin Ca mixed with the granular vegetable pulverized product prepared in the stirring and melting mixer 20 and fed into the supply tube 34 of the low-pressure extruder 30 is moved so that the facing portion moves downward. Each of the pull-out rollers 32 is drawn between the two pull-out rollers 32 that are rotationally driven in opposite directions.
And is sent toward the lower intermediate support plate 35 through the gap between them, and is extruded from the discharge port 36 as an intermediate resin layer C having a constant thickness. In the half part outside each drawer roller 32, the molten synthetic resin Ca is denoted by a symbol C.
As shown in FIG. 2B, the adhesive is adhered in the groove 32a, the surface of which is formed into a semi-cylindrical shape and returns upward, and is integrally adhered to the molten synthetic resin Ca in the supply cylinder 34 and drawn in.
To send out. As described above, the molten synthetic resin Ca is extruded from the discharge port 36 due to viscous friction between the two draw-out rollers 32. Therefore, the rise in the discharge pressure is small, and therefore, the porosity of the molten synthetic resin Ca is not lost. The mixed kenaf core is extruded from the discharge port 36 without being further finely pulverized.

The first skin A formed in advance as described above
Is pulled out from the skin drum Aa in which
Is moving rightward on the support floor 33 of the low-pressure extruder 30 over the lower support roller 16 (FIG. 2).
reference). As described above, in the subsequent third step, the intermediate resin layer C extruded and supplied from the discharge port 36 in the second step, as shown in FIG.
3 on the first epidermis A moving to the right in the longitudinal direction and moves with it.

As shown in FIG. 1, an intermediate resin layer heater 40 and a skin heater 41 are provided above the second support 11 following the support floor 33 of the low-pressure extruder 30. While the first skin A on which the intermediate resin layer C is placed is moving on the upper surface of the second support 11 in the third step, the upper surface of the intermediate resin layer C thereon is heated by the intermediate resin layer heater 40. As a result, the surface temperature of the intermediate resin layer C is 100 to 12
Keep at 0 ° C. Further, the lower surface of the second skin B that is obliquely lowered from the guide roller 18 toward the intermediate resin layer C is heated to 80 to 90 ° C. by the skin heater 41.

Next, in the third step, the second skin B is superimposed on the intermediate resin layer C which is placed on the first skin A and is moving together with the first skin A, and is pressed to press the intermediate resin layer C The fourth step of bonding both skins A and B to both side surfaces of will be described.
As shown in FIGS. 1 and 2, the roller press 50 used in the fourth step includes a machine frame 51 and each of the four rollers 4 supported by the machine frame 51 so as to be rotatable about a horizontal axis parallel to each other.
Lower rollers 52a-52d and upper rollers 53a-5
3d. Lower rollers 52a to 52d
Are arranged side by side on a horizontal plane so as to support the first skin A extending horizontally from the support floor 33 of the low-pressure extruder 30, and the upper rollers 53a to 53d
a is a guide roller located above, the remaining three 53b-53
d is a pressing roller, and these three pressing rollers 53b-
53d is vertically movable to some extent and is elastically urged toward the lower end by a spring. Each roller 52a-5
2d, 53a to 53d are rotated in the direction of the arrow shown in the figure so as to move the synthetic resin laminate to the right.
In FIG. 2, the roller press 50 is used for convenience of drawing.
Is larger than the low-pressure extruder 30.

The second skin B heated by the skin heater 41 while moving obliquely downward from the guide roller 18 is:
Guided by the front upper roller 53a, it is superimposed on the intermediate resin layer C placed on the first skin A, and these are left over.
A pair of lower rollers 52b-52d and upper rollers 53b-5
3d, the upper and lower skins A and B are pressed and bonded to both side surfaces of the intermediate resin layer C in a molten state. The thickness of the manufactured synthetic resin laminate is, for example, 12 mm, and the front pressing roller 53b may rise slightly against the spring.

Next, the fifth step of cooling the synthetic resin laminate bonded in the fourth step will be described. As shown in FIGS. 1 and 3, the cooling press 60 used in the fifth step has a lower press member 61 and an upper press member 62 as main constituent members. The lower press member 61 is connected to the fourth support 13.
It has a planar upper surface fixed to the upper side and having a width slightly larger than the synthetic resin laminate to be manufactured, and the upper surface is supported by the lower rollers 52 a to 52 d of the roller press 50.
A gentle inclined surface 61a is formed at the front and rear ends at the same height as the lower surface of the skin A. The upper press member 62 has a flat lower surface corresponding to the upper surface of the lower press member 61 and formed with inclined surfaces 62a at front and rear ends, and is guided and supported by the guide rod 66 so as to be vertically movable with respect to the lower press member 61. And
The eccentric cam mechanism 65 moves up and down at a time interval of about 1 Hz. Cooling pipes 63 and 64 for passing a cooling medium such as water are formed in the press members 61 and 62, respectively, so that the cooling members are forcibly cooled. Upper press member 62
In the descending state, the lower surface thereof comes into contact with the upper surface of the second skin B by its own weight and presses it (see the solid line in FIG. 3), and the lower surface separates from the upper surface of the second skin B in the ascending state (see FIG. 3). That is, both press members 61 and 62
Varies between the thickness of the synthetic resin laminate and a larger value in a short period (for example, about 1 Hertz).

Since the lower surface of the first skin A is always in contact with the upper surface of the lower press member 61, the lower surface of the synthetic resin laminate is always cooled by the lower press member 61. When the upper press member 62 is lowered, the upper press member 62 and the lower press member 61 are pressed against the upper and lower surfaces of the synthetic resin laminate by its own weight, so that the skins A, The intermediate resin layer C that has just been bonded and is still in a molten state is cooled by heat transfer to the lower press member 61 and the upper press member 62. With the upper press member 62 raised, the synthetic resin laminate can move freely in the longitudinal direction. That is, in the fourth step, the epidermis A,
The synthetic resin laminated plate to which B is bonded is repeatedly moved by the pressing / cooling and releasing of pressing by the upper and lower press members 61 and 62 in a short cycle while passing through the cooling press 60, and the surface temperature is reduced before the cooling press 60. Was 100 to 120 ° C. (150 ° C. or more at the internal temperature), after passing through the cooling press 60, the surface temperature dropped to 30 to 50 ° C. (90 to 100 ° C. at the internal temperature), and the intermediate resin layer C is cooled and solidified.

The take-off machine 7 provided on the rear side of the cooling press 60
In the case of No. 0, the synthetic resin laminated plate is sandwiched between a pair of take-up rollers 71 rotated in the direction of the arrow shown in the figure, and is pulled out rightward and sent to the work roller table 15. The synthetic resin laminate formed continuously as described above is cut to a predetermined length on the work roller table 15.

In the synthetic resin laminate manufactured according to the first embodiment described above, since the intermediate resin layer C is porous and the mixed granular vegetable crushed product is not finely crushed, Can be reduced to reduce the weight of the synthetic resin laminate. In addition, by mixing a vegetable pulverized product, the heat shrinkage rate can be reduced to reduce deformation during molding.

In the method for manufacturing a synthetic resin laminate according to the first embodiment described above, the plastic molten synthetic resin Ca mixed with kenaf core obtained in the first step becomes porous with air therein, The porous molten synthetic resin Ca is extruded from the slit-shaped discharge port 36 in the second step, and both skins A,
Since B is pressed and adhered, it is possible to continuously produce a synthetic resin laminate in which thin skins A and B are adhered to both sides of the porous intermediate resin layer C with high production efficiency.
In addition, as described above, the molten mixed resin Ca that becomes the intermediate resin layer C does not lose its porosity when being extruded from the discharge port 36 in the second step, so that the weight of the synthetic resin laminate to be manufactured can be reduced. Is not impaired.

In the manufacturing method of the first embodiment described above, since a large number of grooves 32a extending in the axial direction are formed on the outer peripheral surface of the pull-out roller 32, the molten synthetic resin Ca The adhesion becomes more reliable, whereby the extrusion of the intermediate resin layer C from the discharge port 36 is also performed reliably, and therefore, the production of the synthetic resin laminate can be performed stably.

In the manufacturing method of the first embodiment described above, the synthetic resin laminate having both skins A and B adhered to both sides of the intermediate resin layer C in the molten state is forcibly cooled.
The pair of press members 61 and 62 are repeatedly sandwiched in a short cycle and moved in the longitudinal direction while being pressed and cooled. Therefore, the distortion caused by cooling is automatically corrected by being sandwiched and pressed between the two press members.

In the manufacturing method of the first embodiment, after the granular synthetic resin stirred by the rotating blade starts melting, the granular vegetable pulverized product is mixed in the first step. Since the granular synthetic resin is agitated by the blade before melting, the granular vegetable pulverized product is not further finely pulverized, and is less likely to be carbonized. As a result, the particle size of the vegetable pulverized product mixed in the intermediate resin layer C is kept relatively large,
The effect of reducing the weight of the synthetic resin laminate and reducing the heat shrinkage can be increased. The timing of feeding the kenaf core which has been pulverized into granules may be just before the synthetic resin is melted, and when using a granular plant pulverized product such as wood chips which is hard to pulverize, the granular synthetic resin and the plant The pulverized product may be simultaneously put into the hopper 21 of the stirring and melting mixer 20, and the granular synthetic resin may be melted by a rotating blade.

In the manufacturing method described above, the joining of the two skins A and B to the intermediate resin layer C is performed later in the second skin B than in the first skin A, and therefore, the bonding of the second skin B is performed. May be insufficient compared to the first skin A due to a decrease in temperature due to heat radiation. However, in the first embodiment, the second skin B is formed on the intermediate resin layer C in the third step.
Immediately before joining, the surfaces of the intermediate resin layer C and the second skin B that are joined to each other are heated by the heaters 40 and 41, so that the temperature drop due to heat radiation is recovered, and the second skin for the intermediate resin layer C is recovered. B is also securely bonded. When the adhesion of the first skin A to the intermediate resin layer C is insufficient, a heater for heating the upper surface of the first skin A may be provided before the low-pressure extruder 30.

As in the first embodiment, the use of synthetic resin pulverized in a granular form as synthetic resin pulverized in a granular form can reduce material costs and reduce the amount of synthetic resin that is discarded. Can be reduced.

In the above-described first embodiment, both the pressing members 61 and 62 of the cooling press 60 are both flat, but these pressing members are to be slightly curved in the longitudinal direction or the lateral direction. It is also possible to produce a curved synthetic resin laminate.

Next, a description will be given of a second embodiment of the synthetic resin laminate and the method of manufacturing the synthetic resin laminate according to the present invention. In the second embodiment, in a first step, a molten synthetic resin Ca is prepared by stirring a granular synthetic resin with a rotating blade, melting it by friction heat, and mixing a granular vegetable pulverized product as a filler. In this case, the only difference from the first embodiment is that a foaming agent is mixed in addition to the granular plant-based pulverized product. Other configurations including the manufacturing apparatus used are the same as those of the first embodiment. Therefore, the difference will be mainly described. A blowing agent suitable for use in this second embodiment has a thermal decomposition temperature of 1
An azodicarbonamide-based or sodium hydrogencarbonate-based one at 80 to 200 ° C.

Next, polypropylene (having a specific gravity of 0.9) as a synthetic resin material is used in the form of granules (including chips) ground into an irregular shape similar to that of the first embodiment, and azo is used as a foaming agent. Dicarbonamide type (EV309 of Eiwa Chemical Co., Ltd., foamed at 180 to 200 ° C)
A description will be given of a second embodiment in which is used. First
In the process, predetermined amounts of the granular synthetic resin material and the foaming agent are put into the hopper 21 of the stirring and melting mixer 20 similar to the first embodiment. In this case, the input amount is 10 parts by weight of the foaming agent with respect to 100 parts by weight of the granular synthetic resin and kenaf core. The synthetic resin and the blowing agent are mixed with a stirring and melting mixer 20.
Is stirred by a plurality of blades rotating in the mixing chamber 23, and the synthetic resin is melted by frictional heat to become plastic, and at the same time, the foaming agent is mixed into the plastic resin which has become plastic. Immediately after the start of melting, a granular (including chip-shaped) kenaf core is put into the hopper 21 and mixed into the molten synthetic resin in the mixing chamber 23. The input timing and input amount of the kenaf core are the same as those in the first embodiment.

If the door under the mixing chamber 23 is opened when the kenaf core is uniformly mixed with the molten synthetic resin, the plastic molten synthetic resin Ca mixed with the foaming agent and the kenaf core is discharged from the discharge port 24, and the low-pressure extruder is used. It is fed into 30 supply cylinders 34. By repeating this, the molten synthetic resin Ca mixed with the kenaf core pulverized product and the foaming agent is successively sent to the supply cylinder 34 of the low-pressure extruder 30. The molten synthetic resin Ca is coarse and porous as a whole with air inside by being stirred by a blade, and the molten synthetic resin itself is a gas generated by thermal decomposition of a foaming agent mixed therein. It is beginning to become finer porous. The molten synthetic resin Ca fed into the supply tube 34 of the low-pressure extruder 30 is extruded from the discharge port 36 by the two extraction rollers 32 at 220 to 240 ° C. as in the case of the first embodiment (second step), The fine porosity of the molten synthetic resin itself by the thermal decomposition of the foaming agent mixed up to that time is almost finished.

The intermediate resin layer C extruded and supplied from the discharge port 36 is moved rightward in the longitudinal direction on the support floor 33 of the low-pressure extruder 30 in the same manner as in the first embodiment. A (third step) and moves along with it, and a second skin B is superimposed thereon, and the lower roller 52
a to 52d and upper rollers 53a to 53d,
Then, the upper and lower skins A and B are pressed and bonded to both side surfaces of the intermediate resin layer C in a molten state (fourth step). The synthetic resin laminate bonded in this way passes through the cooling press 60 in the fifth step including the lower press member 61 and the upper press member 62 as in the first embodiment, and the intermediate resin layer C It is cooled and solidified, pulled out by the take-up roller 71 of the take-up machine 70, and cut on the work roller base 15 into a predetermined length.

The synthetic resin laminate manufactured according to the second embodiment has all the functions and effects described in the first embodiment, as well as the molten synthetic resin itself that becomes the intermediate resin layer C together with the kenaf core. Since the specific porosity is reduced due to the fine porosity, the weight is further reduced. In addition, since the foaming agent is added in the first step in which the synthetic resin in a granular form is stirred by a rotating blade and melted by frictional heat to be plastic, it is diffused into the molten synthetic resin without a special step. Mixed. In the synthetic resin laminate according to the above-described second embodiment, the specific gravity of the intermediate resin layer C is 0.57. On the other hand, a synthetic resin material according to the first embodiment was manufactured under the same conditions except that a waste material of polypropylene having a specific gravity of 0.98 was crushed into granules as a synthetic resin material, and no foaming agent was mixed. The specific gravity of the intermediate resin layer C of the plate is 0.85.

In the second embodiment, a synthetic resin material obtained by pulverizing polypropylene having a specific gravity of 0.9 into granules is used, and a sodium hydrogen carbonate-based foaming agent (trade name of Eiwa Chemical Industry Co., Ltd.) is used. When EE207) was manufactured in the same manner as described above except that 4 parts by weight of 100 parts by weight of granular synthetic resin and kenaf core were used, a synthetic resin laminate having an intermediate resin layer C having a specific gravity of 0.68 was obtained. Was done.
In the second embodiment, a synthetic resin material obtained by pulverizing polypropylene having a specific gravity of 1.1 into granules is used, and a sodium hydrogencarbonate-based foaming agent (product name EV405D of Eiwa Chemical Co., Ltd.) is used as a foaming agent. When manufactured in the same manner as described above except that one part was used per 100 parts of granular synthetic resin and kenaf core by weight ratio, a synthetic resin laminate having an intermediate resin layer C having a specific gravity of 0.73 was obtained.

[0040]

As described above, according to the synthetic resin laminate of the present invention, the intermediate resin layer is made of a coarse porous synthetic resin mixed with granular plant-based pulverized products. Because the specific gravity becomes small by being coarse porous and being mixed with granular vegetable ground products,
The weight of the synthetic resin laminate can be reduced.

In the synthetic resin laminate according to the present invention, when the synthetic resin constituting the intermediate resin layer is foamed with a foaming agent, the specific gravity of the intermediate resin layer is further reduced. The weight can be reduced.

According to the method for producing a synthetic resin laminate according to the present invention, the porous, plastic molten synthetic resin mixed with the granular vegetable pulverized product obtained in the first step is discharged from the discharge port in the second step. There is no loss of porosity since the internal pressure does not rise when extruded, and no more finely ground granular plant grounds, and therefore no increase in specific gravity. Then, in the subsequent third step and fourth step, both skins are pressed and adhered to both sides of the molten intermediate resin layer, so that both sides of the porous intermediate resin layer mixed with the granular vegetable pulverized product are adhered. It is possible to continuously manufacture a lightweight synthetic resin laminate having a thin plate-like skin bonded thereto with high production efficiency.

According to the method of manufacturing a synthetic resin laminate according to the present invention, by forming a large number of grooves extending in the axial direction on the outer peripheral surface of the drawing roller, the intermediate resin layer can be reliably extruded from the discharge port. Therefore, the production of the synthetic resin laminate can be stably performed.

In the method for manufacturing a synthetic resin laminate according to the present invention, the synthetic resin laminate having both skins adhered to both sides of the molten intermediate resin layer obtained in the fourth step is prepared as follows.
According to the fifth aspect of the invention, further comprising a fifth step of cooling between the pair of press members, the synthetic resin laminate in which both skins are adhered to both side surfaces of the intermediate resin layer in a molten state is provided by a pair of press members. Since it moves in the longitudinal direction and is cooled and hardened while being repeatedly pressed and pressed between members in a short cycle, the distortion caused by cooling is automatically corrected by being pressed and pressed between both press members. You.

In the method of manufacturing a synthetic resin laminate according to the present invention, the granular vegetable pulverized product is mixed in the first step before and after the granular synthetic resin stirred by the rotating blade starts melting. According to this, the granular vegetable pulverized product is not further finely pulverized by the stirring of the granular synthetic resin by the blade before melting, and the risk of carbonization is small, so that the intermediate resin layer C The particle size of the vegetable pulverized product mixed in the resin is kept relatively large, and the effect of reducing the weight of the manufactured synthetic resin laminate and reducing the heat shrinkage can be increased.

In the method for manufacturing a synthetic resin laminate according to the present invention, the surfaces of the intermediate resin layer and the second skin that are bonded to each other are bonded immediately before the second skin is bonded on the intermediate resin layer in the third step. According to the configuration in which heating is performed by the heater, bonding and bonding between the second skin and the intermediate resin layer, which may be insufficient in bonding in some cases as compared with the first skin, are surely performed, As a result, the quality of the manufactured synthetic resin laminate can be improved.

According to the method for producing a synthetic resin laminate according to the present invention, in the first step, a foaming agent is further mixed into a molten synthetic resin which has been plasticized by melting by friction heat. Since the synthetic resin itself of the resin layer is also foamed and becomes porous, the weight of the manufactured synthetic resin laminate is further reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an entire apparatus used in an embodiment of a method for manufacturing a synthetic resin laminate according to the present invention.

FIG. 2 is an enlarged sectional view showing a low-pressure extruder and a roller press in the apparatus shown in FIG.

FIG. 3 is an enlarged sectional view showing a structure of a cooling press in the apparatus shown in FIG.

[Explanation of symbols]

32: pull-out roller, 32a: concave groove, 36: discharge port, 4
0, 41: heater, 52a to 52d: lower roller, 53
a to 53d: Upper roller, 61, 62: Press member, A
... first skin, B ... second skin, C ... intermediate resin layer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 31/08 B32B 31/08 4J002 C08J 3/20 CES C08J 3/20 CESB 9/04 103 9/04 103 C08L 97/02 C08L 97/02 101/00 ZAB 101/00 ZAB // B29K 1:00 B29K 1:00 105: 04 105: 04 B29L 9:00 B29L 9:00 (72) Inventor Koichi Oshitani Toyota, Aichi Araco Co., Ltd. (25) Inventor Shinji Tomita 25, Ueike Pond, Yoshihara-cho, Toyota City, Aichi Prefecture F-term (reference) 4F070 AA15 AA66 AA71 AB09 AB11 AC16 AC47 AE12 FA01 FA03 FB06 FC02 4F074 AA02 AA24 AA97 BA03 BA13 CA22 CC04X CC22X CE02 4F100 AK01A AK01B AK01C AP10A AP10H AR00B AR00C AT00B AT00C BA03 BA06 BA10B BA10C CA01A CA01H CA23A CA23H DJ01A DJ10A EA021 EH171 EJ172 EJ192 EJ422 EJ502 GB08 GB33 JL02 JL03 JL16 4F201 AA01 AA50 AC01 AG01 AG03 AG20 AK01 AK02 BA01 BC01 BC13 BC25 BD05 BK15 BK33 BK38 BK55 4F207 AA01 AG01 KB01 KA01 AG01 KBA1 KK90 KW21 4J002 AH002 BB011 BB111 BD031 BN151 DE206 EQ016 FD012 FD326

Claims (9)

[Claims] 1. A synthetic resin laminated plate characterized in that a thin plate-like skin is integrally adhered to both side surfaces of an intermediate resin layer made of a coarse porous synthetic resin mixed with a granular vegetable crushed product. . 2. The synthetic resin laminate according to claim 1, wherein the synthetic resin constituting the intermediate resin layer is foamed with a foaming agent. 3. A first step of preparing a molten synthetic resin in which a granular synthetic resin is stirred by a rotating blade and melted by frictional heat to be plasticized, and a granular vegetable pulverized product is mixed as a filler. A second step of feeding the synthetic resin through a gap between a pair of pull-out rollers rotating in opposite directions and extruding it as a porous intermediate resin layer from a slit-shaped discharge port; and a preformed elongated continuous thin plate. A third step of supplying the molten intermediate resin layer extruded in the second step onto the first skin moving in the longitudinal direction, and placing the intermediate resin layer on the first skin and moving therewith The intermediate resin layer is formed by laminating a second skin that is made of an elongated continuous thin plate that is formed in advance and that is moving in the longitudinal direction. A fourth step of pressing and adhering the two skins to both sides of the intermediate resin layer, wherein the synthetic resin is formed by integrally bonding thin plate-shaped skins to both sides of the porous intermediate resin layer. A method for manufacturing a laminate. 4. The method for manufacturing a synthetic resin laminate according to claim 3, wherein a plurality of grooves extending in the axial direction are formed on the outer peripheral surface of the drawer roller. 5. A synthetic resin laminate having both skins adhered to both sides of the molten intermediate resin layer obtained in the fourth step, both of which are forcibly cooled and a gap between them. 5. The method according to claim 3, further comprising a fifth step of cooling through a pair of press members that change between a thickness of the synthetic resin laminate and a value greater than the short cycle. 3. The method for producing a synthetic resin laminate according to item 1. 6. The method according to claim 3, wherein the mixing of the granular plant-based pulverized product in the first step is performed before or after the granular synthetic resin stirred by a rotating blade starts melting. A method for producing the synthetic resin laminate according to claim 5. 7. Immediately before joining the second skin on the intermediate resin layer in the third step, the surfaces of the intermediate resin layer and the second skin that are joined to each other are heated by a heater. Any one of claims 3 to 6 characterized by the above-mentioned.
Item 14. The method for producing a synthetic resin laminate according to item 4. 8. The method according to claim 3, wherein in the first step, a blowing agent is further mixed into the molten synthetic resin which has been plasticized by being melted by frictional heat. A method for producing the synthetic resin laminate according to the above. 9. The method for producing a synthetic resin laminate according to claim 3, wherein the synthetic resin pulverized in a granular form is obtained by pulverizing a waste material of the synthetic resin into a granular form.