JPH0647798A - Method for manufacturing extrusion-molded product and manufacturing device - Google Patents

Abstract

PURPOSE:To prevent a lubricant from becoming deflected and supplying the lubricant stably by extruding and forming a cross-linked resin material which passes through a long land part with the concurrent feed of the lubricant, through a porous element across the entire periphery of the cross-linked resin material. CONSTITUTION:A resin material is extruded into a forming die 22 by an extruder 21, and passes through a porous element 25 in a long land part 24a. The porous element 25 is a passage for the resin and concurrently a gas feed part, and if a gas is compressed by a pump or any other means from a lubricant introduction orifice 27, the as runs into a reservoir part 26 outside the porous element 25. Next, the gas comes in contact with the external wash surface of the cross-linking resin material, passing through the porous element 25. In this case, a film is formed on the external surface of the cross-linking resin material, and the material is cross-linked by heating of the long land part 24a. Thus, it is possible to eliminate a deviation, in the parallelism of the opposite surface of a slit, which generates when the die is set as is the case with the supply of the lubricant from the slit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an extruded product in which a crosslinkable resin is extruded into a die device having a long land portion, and a manufacturing apparatus used in the method for manufacturing the extruded product.

[0002]

2. Description of the Related Art Conventionally, as a method of continuously extruding a crosslinkable resin material, a method of shaping and heating using a die device having a long land portion is known. For example, in Japanese Unexamined Patent Publication (Kokai) No. 48-96656, a crosslinkable resin material is heated and vulcanized by molding a vulcanizable resin composition and using a die device having a long land portion for vulcanizing by heating. A continuous molding method is disclosed.

According to this method, the temperature and length of the long land portion are determined so that the crosslinking reaction of the crosslinkable resin material passing therethrough is completed, and a crosslinked molded article is continuously obtained from the land portion outlet. is there. In this method, since a high back pressure is applied to the plasticizing zone of the crosslinkable molding material due to the existence of the long land portion in the molding process, the inner wall of the long land and the molding passing therethrough. A method is adopted in which a lubricant is supplied to the interface between the material or the molded product to reduce the frictional resistance between the inner wall of the long land and the molding material or the molded product.

In this molding method, in order to extrude the crosslinkable resin material continuously and satisfactorily, an optimum amount of the lubricant is uniformly distributed on the outer surface of the extruded crosslinkable resin material to stabilize the extrusion. It is necessary to form a lubricated film. As shown in FIG. 9, a conventional extrusion molding apparatus is provided with two flanges (d) and (d) between an extruder (a) and a die device (c) having a long land (b). Flange (d)
A thin metal foil of the required shape between the facing surfaces of (d) (f)
By inserting both flanges (d) and (d) with a bolt etc., the resin passage (g) is placed inside the metal foil (f).
Slits (chi) were provided radially with respect to. Then, the lubricant is continuously or discontinuously press-fitted by a pump or other means from the lubricant introducing port (li) communicating with the slit (h), so that the crosslinkable resin material passing through the resin passage (g) The method of supplying the lubricant to the outer surface has been taken.

[0005]

However, in order to maintain an ideal lubrication state, it is not always easy to stably supply the lubricant, and in the supply of the lubricant by the slit (h), There is a problem that the supply stability depends on the slit spacing and the parallelism of the facing surfaces on both sides of the slit. That is, when the lubricant is press-fitted from the lubricant introduction port (i), if the slit (h) is narrowed in order to supply the lubricant at a high pressure, it is difficult to maintain the parallelism of the facing surfaces forming the slit. , There is a risk that the lubricant will cause partial drift. On the other hand, if the slit is widened, the supply pressure of the lubricant decreases, so that the supply of the lubricant to the outer surface of the crosslinkable resin material becomes unstable under the influence of the fluctuation of the extrusion pressure of the resin. Such uneven flow of lubricant or unstable supply of lubricant easily causes film breakage of the lubricant film formed between the crosslinkable resin material and the inner surface of the long land (b), and therefore the surface of the molded product In addition to scratching the surface of the molded product and degrading the quality and commercial value of the molded product, it also causes discharge fluctuations due to film breakage, making it difficult to secure stable productivity. Therefore, it is an important technical subject to prevent uneven flow of the lubricant and to stably supply the lubricant.

In the method using a liquid lubricant, it is necessary to wash the lubricant adhering to the surface of the molded product in the next step. Moreover, depending on the type of lubricant used, cleaning is difficult, and the lubricant remains in the molded product, which may lead to deterioration of the quality of the molded product or deterioration of the environment of the manufacturing equipment. A method of removing the lubricant near the tip of the land has been proposed (Japanese Patent Laid-Open No. 48-9665).
No. 6), it cannot be completely removed.

An object of the present invention is to provide a method for preventing uneven flow of a lubricant and stably supplying the lubricant in a manufacturing method of extruding and molding a resin material using a die device having a long land portion. To do.

Another object of the present invention is to provide a method for producing an extruded product by using a long land die, which also uses gas as a lubricant.

A further object of the present invention is to provide a manufacturing apparatus used in each of the above methods.

[0010]

The method for producing an extrusion-molded article according to the present invention is a method for extruding a crosslinkable resin material from a shaping mold to a long land portion of a die device. The cross-linkable resin material is extruded while supplying the lubricant through the porous body over the entire circumference of the cross-linkable resin material.

The method for producing an extrusion-molded article according to the second aspect of the present invention is the same as the above-mentioned method for producing an extruded article according to the present invention, from the inlet of the crosslinkable resin material into the inside of the porous body to the inner peripheral surface of the porous body through the auxiliary porous body. It supplies an auxiliary lubricant.

The method for producing an extrusion-molded article according to the third aspect of the present invention is the method according to the present invention or the second aspect of the present invention, wherein
A larger amount of lubricant is supplied to the chamber near the inlet of the crosslinkable resin material through the porous material that passes through the long land part divided into the step chambers, through the porous body. Meanwhile, the crosslinkable resin material is extruded.

The manufacturing apparatus used in the manufacturing method of the present invention is
An extruder for the crosslinkable resin material, a shaping die provided on the exit side of the extruder, and a die device provided on the exit side of the shaping die and having a long land portion, further comprising: A porous body was provided in the long land portion so as to cover the passage of the crosslinkable resin material, and a passage portion on the outer side of the porous body was used as a lubricant reservoir, and the reservoir portion was formed in the long land portion. It is configured to communicate with the lubricant introduction port.

Further, in the production apparatus used in the production method of the present invention 2, in order to make extrusion molding of the crosslinkable resin material more stable, an auxiliary porous body is provided on the crosslinkable resin material inlet side of the porous body. It is a thing.

Further, the manufacturing apparatus used in the manufacturing method of the present invention 3 has a long land portion divided into at least two stages of chambers, and it is possible to supply lubricants of different flow rates in the respective chambers. Is.

In any of the manufacturing methods of the present invention, when the gas is supplied from the porous body, it depends on the extrusion conditions of the resin, the cross-sectional shape of the porous body, the length of the long land die, etc. When the cross-sectional shape of the porous body is cylindrical, the permeation unit area of the porous body is preferably 0.5 to ⁵ cm ³ / cm ² sec, and when the cross-sectional shape of the porous body is the slit shape, the porous body is It is preferable that the permeation unit area is 5 to 20 cm ³ / cm ² sec. Furthermore, when gas is supplied from the auxiliary porous body, the permeation unit area of the auxiliary porous body is 0.2 to 20 cm.
^It is preferably ³ / cm ² sec.

In order to control the gas permeation amount, selection of the porous body is important. Generally, it is the porosity, the pore diameter, and the thickness that determine the gas permeation amount of the porous body. Regarding the thickness, there is a constraint on the mold structure and a constraint on the production of the porous body, and therefore the thickness cannot be extremely increased, and the strength cannot be too thin, so 0.2 to 5 cm is preferable,
More preferably, it is 0.5 to 2 cm.

Since the thickness of the porous body is greatly restricted as described above, the gas permeation amount of the porous body can be controlled by the remaining porosity and pore diameter, and the porosity of the porous body and the auxiliary porous body can be controlled. Is preferably 10 to 40%, the pore diameter is preferably 0.1 to 10 μm, and more preferably the porosity is 15 to 30% and the pore diameter is 0.3 to 5 μm.

Further, in any of the manufacturing apparatuses of the present invention, the opening area of the porous body is 1.2 to 2.0 times as large as the exit area of the molding die for molding the crosslinkable resin material. preferable.

In the method for producing an extrusion-molded article of the present invention 3, at least 2 in the method of the present invention or the production method of the present invention 2.
A larger amount of lubricant is supplied to the chamber near the inlet of the crosslinkable resin material through the porous material that passes through the long land part divided into the step chambers, through the porous body. Meanwhile, the crosslinkable resin material is extruded. The cross-sectional shape of the resin passage formed by the porous body is not particularly limited in any of the above manufacturing apparatuses, and may be, for example, a tubular shape, a slit shape, a rectangular shape, or a corrugated plate shape. , U-shaped,
It may have an irregular shape such as a corrugated plate. Further, it may have a cross-sectional shape corresponding to a hollow molded body, a molded body with an undercut, or a molded body with ribs. Next, each component of the present invention will be described in detail.

(Lubricant) As a liquid lubricant, decomposition and boiling are less likely to occur at the molding temperature of the resin used,
Moreover, a chemically stable substance that does not melt into the resin and does not accelerate the deterioration of the resin is preferable. For example, examples of lubricants that satisfy such conditions include liquid polysiloxanes (polydimethylsiloxane, polymethylsiloxane, etc.), polyhydric alcohols such as ethylene glycol, and their alkyl esters and alkyl ethers, polyoxyalkylenes. And alkyl esters and alkyl ethers thereof, polyoxyalkylenes and copolymers of two or more kinds of alkylene oxides, and the like. Of these, water-soluble surfactants such as polyhydric alcohols, which are easy to remove after adhering to the surface of the molded article, are preferable.

The gas lubricant is preferably one that does not react with the resin material and does not exert an inhibitory effect on radical formation during the crosslinking reaction, and specific examples thereof include carbon dioxide gas and nitrogen gas. The lubricant used in the production method of the present invention may be a liquid lubricant or a gas lubricant, but the lubricant may not remain in the obtained molded product, Is preferred.

(Porous Body, Auxiliary Porous Body) The porous body and the material forming the auxiliary porous body are, for example, metal-based materials mainly containing aluminum, stainless steel, titanium, gold, silver, copper, There are non-metallic materials mainly containing alumina, mullite, silicic acid, zirconia and the like. The pressure and flow rate required to supply the lubricant are determined by the type of lubricant used, the pore diameter, the porosity, and the thickness of the porous body. Also,
In order to apply the lubricant uniformly to the interface, it is necessary to select one having a sharp pore distribution and being uniformly dispersed. A non-ferrous metal-based material is preferably used as the porous body satisfying such conditions.

(Heating Method) The length of the long land portion is determined by the crosslinkable resin molding material used and the inner diameter or wall thickness of the molded product. A heating method for accelerating the crosslinking reaction is generally arbitrary, but electric heating is the simplest and the heating conditions are easy to control. The temperature conditions do not have to be the same over the entire long land portion, but it is preferable to divide the zone into several zones and set the temperature conditions and heating time most suitable for the molding material.

(Molding Material) As the crosslinkable resin material, any crosslinkable resin material can be used. Specifically, there are aminoplasts, phenoplasts, epoxy resins, unsaturated polyester resins and other thermosetting resins. Further, there are crosslinkable thermoplastic resins containing a crosslinker and natural or synthetic rubbers.

The thermoplastic resin is, for example, polyethylene, polystyrene, polypropylene, polyvinyl chloride,
Examples thereof include nylon, copolymers such as ethylene-propylene copolymers and ethylene-vinyl acetate copolymers, and mixtures of two or more thereof. Further, additives such as synthetic rubber, paraffin, different types of thermoplastic resins, plasticizers, pigments, foaming agents, flame retardants, and antistatic agents may be mixed with these thermoplastic resins. In addition, any resin that causes a crosslinking reaction by heating, such as a methylol acrylamide polymer, a metal oxide-containing carboxylic acid polymer, or an unsaturated polyester, can be used.

(Crosslinking Agent) As the crosslinking agent, a crosslinking agent having a decomposition temperature higher than the melting temperature of the thermoplastic resin and a crosslinking agent suitable for crosslinking the resin may be appropriately selected. For example, dicumyl peroxide and di- t-butyl peroxide, t
-Butylcumyl peroxide, diisopropylbenzene hydroperoxide, α, α '(-bis-t-butylperoxy-p-diisopropyl) benzene, 2.5
It is an organic peroxide such as dimethyl-2,5-di-(-t-butylperoxy) hexane or a mixture of two or more thereof. If necessary, an auxiliary agent such as a crosslinking accelerator and a crosslinking retarder is mixed.

The amount of these cross-linking agents used depends on the molecular weight of the thermoplastic resin used, the molecular weight distribution, the molecular structure such as the number of branches, and the like.
It should be determined depending on the decomposition temperature of the cross-linking agent and the required degree of cross-linking, but it is preferably 0.1 to 10% by weight, more preferably 0.2 to 2% by weight.

[0029]

In the manufacturing method using this porous body, the lubricant is uniformly supplied through the porous body over the entire circumference of the crosslinkable resin material to be extruded. The lubricant pressure for stable supply of the lubricant can be freely set by selecting the pore diameter, porosity and thickness (perpendicular to the molding material flow direction) of the porous body. . Furthermore, by making the length of the porous body (parallel to the flow direction of the molding material) longer, it is possible to widen the interface between the molding material or the molded product and the lubricant, and the formation of the lubricating film is more stable. Be converted.

Further, in the manufacturing apparatus of the present invention in which the porous body is provided in the long land portion of the die device, when a gas is used as the lubricant, the entire circumferential surface of the crosslinkable resin material within the long land portion is used. The gas evenly contacts the porous body to form a lubricating thin film on the entire surface of the crosslinkable resin material. Since the crosslinkable resin material passes through the long land portion with a lubricating thin film formed on the entire surface, the surface of the extruded crosslinkable resin material is not damaged.

10 to 4 porous bodies and auxiliary porous bodies
When it has a porosity of 0% and a pore diameter of 0.1 to 10 μm, the permeation unit area suitable for the gas permeation amount of each porous body is easily in the range of 0.5 to ²⁰ cm ³ / cm ² sec. Can be maintained. When the amount of gas permeation of this porous material is 0.5 cm ³ / cm ² sec or less, the crosslinkability of the crosslinkable resin material varies due to fluctuations in the extrusion state of the crosslinkable resin material and uneven flow of the gas lubricant caused by low resin rigidity. Adhesion of the resin material to the porous body occurs, causing clogging of the porous body and retention of the resin. On the other hand, when the gas permeation rate of the porous body is 20 cm ³ / cm ² sec or more, the molded product vibrates due to the uneven flow of the gas flow due to the resin flow rate, and when this vibration occurs, the molded product moves to the inner wall of the porous body. Since the adherence and the detachment of the resin are repeated, the surface of the molded product may be damaged.

In a manufacturing apparatus in which the opening area of the porous body is 1.2 to 2.0 times the exit area of the shaping die for shaping the crosslinkable resin material, the extruded resin material is porous from the shaping die. Since the isotropic pressure received by the shaping die is released in the porous body when extruded into the porous body, the crosslinkable resin material material expands. At this time, since the opening area of the porous body is larger than the exit area of the shaping die, the crosslinkable resin material swells in a conical shape that spreads from the inlet of the porous body toward the exit, and the crosslinkable resin material and the porous body. Creates a gap between the inner surfaces of the. The lubricant stays in this gap and promotes the formation of a lubricating film, especially at the inlet of the porous body. Further, the lubricant retained in the gap between the crosslinkable resin material and the inner surface of the porous body also serves as a cushion of the crosslinkable resin material molded product. However, when the opening area of the porous body exceeds 2.0 times the exit area of the shaping die, the gap between the crosslinkable resin material and the inner surface of the porous body becomes too large, and the heating efficiency is significantly reduced. The upper limit was 2.0 times.

When the opening area of the porous body is made larger than the exit area of the mold for shaping the crosslinkable resin material as described above, the auxiliary porous material is provided on the crosslinkable resin material inlet side of the porous body. The body can be easily arranged. Then, by supplying the auxiliary gas to the inner peripheral surface of the porous body, the auxiliary gas is press-fitted from the root portion of the crosslinkable resin material that expands parabolically due to the ballast effect, and the auxiliary gas causes the vicinity of the inlet of the porous body. Since the formation of the lubricating film on the surface of the crosslinkable resin material, which is apt to adhere, is promoted, the adhesion is prevented.

When gas is used as the lubricant, it is not necessary to clean the surface of the molded product after extrusion, and it is possible to prevent deterioration of the quality of the molded product and deterioration of equipment environment.

[0035]

EXAMPLES Examples of a method and an apparatus for manufacturing an extrusion molded article using the crosslinkable resin material according to the present invention will be described below.

Example 1 An extrusion molding apparatus used in the present invention is provided, for example, as shown in FIG. 1, with an extruder (21) for a crosslinkable resin material and an outlet side of the extruder (21). Shaped mold
(22) and a die device (24) provided on the outlet (22b) side of the shaping die (22) and having a long land portion (24a),
Further, a cylindrical porous body (25) is concentrically provided in the long land portion (24a), and a passage portion on the outer side of the porous body (25) serves as a lubricant reservoir portion (26). Part (26) is long land part
It communicates with the lubricant inlet (27) formed in (24a).

In the case of extrusion molding using a gas as a lubricant in the above-mentioned manufacturing apparatus, first, a resin material preliminarily blended with a cross-linking agent is extruded by an extruder (21) into a mold (22), and a long length is formed. It passes through the inside of the porous body (25) of the land portion (24a).
This porous body (25) is a resin passage and gas supply part, and when gas is pressed in from the lubricant introduction port (27) by a pump or other means, this is a reservoir part outside the porous body (25). After flowing into (26), it passes through the porous body (25) and comes into contact with the entire outer surface of the crosslinkable resin material. At this time, a thin film is formed on the outer surface of the crosslinkable resin material, and at the same time, the long land portion (24
The crosslinkable resin material is crosslinked by the heating of a).

<Example 2> An example of a manufacturing method using the manufacturing apparatus of Example 1 will be described. An extruder (21) shown in Fig. 1 is described.
The diameter of the passage is φ50 mm and the outlet (22a) of the mold (22)
The diameter and the opening diameter (R) of the porous body (25) were set to 15 mm.
Next, 4 kg / h of a cross-linkable resin material prepared by mixing 1.0 part by weight of a cross-linking agent (dicumyl peroxide) with 100 parts by weight of low-density polyethylene (trade name; polyethylene G201 manufactured by Sumitomo Chemical Co., Ltd.). Extruded in volume. The extruded crosslinkable resin material passes through the tapered outlet (22a) of the shaping die, is shaped into a lot shape of φ15 mm, and then passes through the resin passage of the porous body (25) that supplies the lubricant. To do. At this time, the resin temperature of the shaping die (22) connected to the exit of the extruder (21) was 125 ° C.

Nitrogen gas was used as a lubricant, and the inlet (27)
Nitrogen gas was continuously supplied at a pressure of 1 kg / cm ² for 3.0 cm ³ / cm ² sec. The crosslinkable resin material that has passed through the porous body (25) and has been subjected to lubrication has a long land portion (24a)
It was heated at 60 ° C. for 3 minutes and extruded to the outside. The molded product according to this example has a diameter of 14.8 mm and a gel fraction of about 25.
%, A rod-shaped molded product having a smooth surface.

Comparative Example 1 A polyoxyethylene-propylene copolymer (manufactured by Nissan Unilube Co., Ltd. as a lubricant was used as a lubricant by a conventional slit method (slit thickness 80 μm) instead of the tubular porous body (25). Name; 50MB-26X). The other conditions were the same as in Example 4 above. Polyoxyethylene-propylene copolymer was added to 5
It was supplied at cc / min, and the molded product coming out of the die was put in a water tank for cleaning.

The obtained molded product was a rod-shaped molded product having a gel content of 30% and a smooth surface, but the polyoxyethylene-propylene copolymer attached to the surface of the molded product was not completely removed, I had to wipe it off again with a cloth.

<Example 3> An example of another method for producing an extrusion-molded article using the extrusion-molding production apparatus of Example 1 will be described. The extruder (21) has an outlet diameter of 50 mm and a molding die. (2
The diameter of the outlet (22b) of 2) and the opening diameter (R) of the porous body (25) were both set to 15 mm. Next, low-density polyethylene (Sumitomo Chemical Co., Ltd., trade name; high-pressure polyethylene G201) 100
A resin material in which 1.0 part by weight of a cross-linking agent (dicumyl peroxide) was mixed in parts by weight was extruded at an extrusion rate of 5 kg / h. At this time, the supply amount of nitrogen gas is a porous body of alumina.
The permeation unit area of (25) was set to 2.0 cm ³ / cm ² sec.
The resin temperature of the shaping mold was 125 ° C.

Crosslinkable resin material Material is long land (24a)
It was heated inside at 160 ° C. for 3 minutes and extruded to the outside. The molded product according to this example was a rod-shaped molded product having a diameter of 14.8 mm. The amount of gas supplied was 10 cm ³ / cm ² sec per unit area of permeation of the porous body (25), but the above 2.0 cm ³ / cm ² sec caused less vibration of the molding resin. The discharge non-variability was also excellent. Further, the supply amount of the above gas is 0.3 cm ³ / cm per permeation unit area of the porous body (25).
^{Although it was set to 2} sec, the above-mentioned 2.0 cm ³ / cm ² sec had a better gas lubrication action.

<Embodiment 4> FIG. 2 shows another embodiment of the extrusion molding apparatus of the present invention, which passes through an extruder (31), a molding die (molding region) (32) and the inside thereof. A die (lubricated cross-linking area) (34) having a long land portion (34a) that determines the length and temperature at which the cross-linking reaction of the cross-linkable resin molding material is substantially completed,
A cylindrical porous body (35) concentrically provided in the long land portion (34a) is provided. And, in this example, the porous body
The opening diameter (R) of (35) is 1. of the outlet (32a) diameter of the shaping die (32).
It is designed to be 3 times (1.69 times the area of the outlet (32a)). When using a liquid lubricant, a lubricant inlet (37) is provided on the upper surface of the long land (34a).
The liquid lubricant is press-fitted into the reservoir (36) through the inlet (37), then passes through the porous body (35) and is supplied to the entire circumference of the crosslinkable resin material.

At this time, as shown in FIG. 4, the crosslinkable resin material (P) is shaped by the shaping die (32), and then the porous body (3
Extruded to 5). At this time, the crosslinkable resin material that is subjected to isotropic pressure from the shaping die (32) expands conically in the porous body (35) due to pressure release (balus effect), but the porous body (35 )
By setting the opening diameter (R) of the resin to a diameter that matches the expansion amount in advance, molding can be performed without rubbing the crosslinkable resin material on the inner wall surface of the porous body (35). Therefore, the surface of the extrusion molded product becomes smoother. In this case, on the inlet side of the porous body (35), a wider gap (S) is formed between the base portion of the crosslinkable resin material (P) expanded in a cone shape due to pressure release, and a lubricant is formed in that portion. Is more supplied, so that lubrication is promoted especially at the inlet side of the porous body where the molded product is easily scratched.

<Fifth Embodiment> FIG. 3 shows still another embodiment of the extrusion molding apparatus, which is basically the same as the apparatus of the fourth embodiment. Extruder (41), mold (42), long land (44a)
And a cylindrical porous body (45).
A gas (lubricant) introduction part (47) is provided on the lower surface of the long land part (44a) and communicates with the reservoir part (46). In the present example, the opening diameter (R) of the porous body (45) is the shaping die (42).
1.4 times the diameter of the outlet (42a) of the outlet (1.96 of the area of the outlet (32a)
Doubled).

Regarding the expansion amount (balus effect) of the crosslinkable resin material, in the example of FIG. 4, it increases with the shear rate of the extrudate, and the flow path length (L) of the shaping zone and its diameter (D ) Ratio L
The larger / D is, the smaller it is. The Varas effect was measured with a flow tester for various shear rates, L / D. The result is as shown in FIG. 5, which was about 1.5 times. Therefore, even in the apparatus of the above embodiment, it is considered that the opening diameter of the porous body (45) and the outlet diameter of the shaping die (42) should be about 1.5 times. However, unlike the flow tester, the actual extrusion flow state is different from the flow tester because the resin is dragged in the extrusion direction by the take-off machine and the viscosity of the lubricant drags the resin in the flow direction. Can be said to be low. Further, when L / D exceeds 1.5 times, the porous body (45)
The gap between the resin and the crosslinkable resin material is too large, resulting in poor heating efficiency in that portion. Further, if L / D is made too small, the molded product is rubbed against the inner wall surface of the porous body, so that the molded product is damaged. Therefore, L / D is preferably in the range of 1.1 to 1.5, more preferably 1.1 to 1.3.

Example 6 An example of a manufacturing method using the apparatus for manufacturing an extrusion-molded article shown in FIG. 2 is shown. The inner diameter of the extruder (31) is set to 50 mm, while the outlet (32a) of the shaping die is used. Diameter is φ1
The opening diameter (R) of the porous body (35) was 13 mm. Next, a resin material prepared by mixing 1.0 part by weight of a crosslinking agent (dicumyl peroxide) with 100 parts by weight of low-density polyethylene (trade name; high-pressure polyethylene G201, manufactured by Sumitomo Chemical Co., Ltd.) is extruded at about 5 kg / h. Extruded in volume. The extruded crosslinkable material is shaped into a rod by a shaping die (32) and then passes through a porous body (35) which supplies a liquid lubricant. At this time, the resin temperature of the shaping die was 125 ° C.

Polyoxyethylene-propylene copolymer as a lubricant (manufactured by Nissan Unilube, trade name: 50)
MB-26X) was supplied at 5 cc / min from the lubricant inlet (37) via a supply pump. The long land portion (34a) was heated at 160 ° C. for 3 minutes and extruded to the outside. The molded product obtained in this example has a diameter of 12.7 mm and a gel fraction of 3
A rod-shaped molded product having a surface smoothness of 0% could be continuously and stably molded without fluctuation in discharge.

When the outlet diameter (32a) of the shaping die and the opening diameter (R) of the porous body (35) are set to the same 10 mm,
The molded product had a diameter of 9.8 mm and a gel fraction of 33%. In addition, the outlet (32a) of the shaping die has a diameter of 10 mm, and the porous body
When the opening diameter (R) of (35) was 15 mm, the molded product had a diameter of 14.7 mm and a gel fraction of 23%, and the crosslinking efficiency was slightly deteriorated.

<Embodiment 7> FIG. 6 shows still another embodiment of the extrusion molding apparatus of the present invention. The whole structure is the same as that of the above embodiment, and in this embodiment, the long land portion (74a) is used. ), The opening diameter (R) of the cylindrical porous body (75) is larger than the diameter of the outlet (72a) of the shaping die (72), and the shaping die (72) and the porous body (75)
The auxiliary porous body (78) is provided at the step portion caused by the difference in diameter between the auxiliary porous body (78) and the auxiliary porous body (78). The auxiliary porous body (78) is a dedicated gas inlet
It has (79).

<Embodiment 8> An extrusion-molded article manufacturing apparatus shown in FIG. 7 is a modification of the manufacturing apparatus of Example 7, and includes a molding die (82) and a long land portion (84a). Cylindrical porous body (85)
The auxiliary porous body (88) is lengthened when there are few step portions caused by the difference in the opening diameters of the auxiliary porous body (88).

<Example 9> The manufacturing apparatus of Example 7 was used.
Explaining an example of the manufacturing method, the exit diameter of the extruder (71) is φ5.
0 mm and the diameter of the outlet (72a) of the molding die (72) is 10 m
m, the opening diameter (R) of the porous body (75) of the long land (74a)
It was set to 13 mm. Next, low-density polyethylene (Sumitomo Chemical
Gakusha, trade name; high pressure polyethylene G201) 100
1.0 part by weight of cross-linking agent (dicumyl peroxide)
Extruding a resin material containing 5 parts by weight at an extrusion rate of 5 kg / h
It was Also, the nitrogen gas supply amount from the porous body (75) is 3.0.
cm³/cm ²It can be supplied to the entire outer surface of the crosslinkable resin material in sec.
The amount of gas supplied from the auxiliary porous body (78) is 3.0 cm.³/cm²s
It was supplied to the inner peripheral surface of the porous body (75) by ec. Long land part (7
In 4a), heat the resin at 160 ° C for 3 minutes to remove the resin from the outside.
Extruded into. The rod-shaped molded article according to this example has a diameter of 12.
7 mm, and the long land part (74a) to the porous body (75)
Molding was smooth without resin adhesion.

<Example 10> The nitrogen gas supply rate of the porous body (75) of the long land portion (74a) was set to 3.0 cm ³ / cm ² sec, and the other conditions were the same as in Example 9 above. Molded.

From Example 9 above, the vibration of the resin during extrusion molding was further reduced, and the resin did not adhere to the porous body (75).

<Embodiment 11> FIG. 8 shows still another embodiment of the extrusion molding apparatus of the present invention, in which the overall structure is the same as that of the above embodiment, and the extruder (91) and the molding die are used. (92) Die (94) having long land portions (94a), (94b) divided into two stages,
It is provided with rectangular porous bodies (95a) and (95b). And
Gas (lubricant) introduction parts (97a) and (97b) are provided on the lower surfaces of the long land parts (94a) and (94b) and communicate with the reservoir parts (96a) and (96b).

<Embodiment 12> The manufacturing apparatus of Embodiment 11 is used.
As an example of the manufacturing method that was described above, the inner diameter of the extruder (91) was
While the width is 50 mm, the width (200) of the exit (92a) of the shaping die
mm, thickness 5 mm, long land part divided into two stages
The length of the first chamber (94a) of the
Length of chamber (94b) is 600mm, porous body (95a),
The opening of (95b) had a width of 220 mm and a thickness of 7 mm. Next
Low density polyethylene (Sumitomo Chemical Co., Ltd., trade name; high pressure
Method Polyethylene G201) 100 parts by weight of cross-linking agent
Resin material containing 1.0 part by weight of (mil peroxide)
The material was extruded at an extrusion rate of about 5 kg / h. In addition, the first
The nitrogen gas supply rate from the porous body (95a) to the chamber is 40
cm³/cm²In sec, is the porous body (95b) in the second chamber?
Supply nitrogen gas from 7 cm ³/cm²External surface of crosslinkable resin material in sec
Supplied over the entire surface. At this time, the extruder (91) was connected to the outlet
The resin temperature of the shaping die (92) was 125 ° C. Extruded
The crosslinkable material was shaped into a rod with a shaping die (92).
After that, it passed through a porous body (95) supplying a gaseous lubricant.
Long land parts (94a) and (94b) are heated at 150 ℃ for 5 minutes
The molded product obtained by extruding the resin outside has a width of 18
0 mm, thickness 60 mm, gel fraction 45%, good surface property
It was a molded product.

<Comparative Example 2> The same as Example 12 except that the nitrogen gas was supplied to the first chamber from the porous body (95a) at a flow rate of 7 cm ³ / cm ² sec over the entire outer surface of the crosslinkable resin material. I chose The resin adhered to the vicinity of the connection between the first chamber and the shaping die, and the crosslinked resin was clogged in the extruder, and extrusion molding could not be performed.

[0059]

According to the present invention, the crosslinkable resin material extruded from the extruder has a uniform lubricant throughout the entire circumference of the crosslinkable resin material through the porous body in the long land portion of the die device. Supplied. Therefore, the problem of the parallelism deviation of the facing surfaces of the slit, which occurs when the mold is set, as in the conventional case where the lubricant is supplied from the slit, is completely eliminated, and the drift of the lubricant can be eliminated.

Further, in the present invention, by providing the auxiliary porous body on the inlet side of the porous body, the formation of the lubricating film on the outer peripheral surface of the crosslinkable resin material is further promoted, and the extrusion molded article having no surface scratches or the like. Can be molded more reliably. Further, the long land portion is divided into at least two stages of chambers, and the entire circumference of the passing crosslinkable resin material is covered with a porous body, and a larger amount than other chambers is provided in the chamber close to the inlet of the crosslinkable resin material. By supplying the above lubricant, it is possible to prevent the resin generated in the initial stage of extrusion from adhering to the mold surface, and it is possible to stably mold even a sheet-shaped molded product.

Further, by adjusting the pore diameter and porosity of each of the above porous bodies, the lubricant can be supplied under arbitrary conditions corresponding to the extrusion molding conditions.

In the extrusion molding apparatus of the present invention, the cross-linking resin material extruded from the shaping die expands by making the opening area of the porous body wider than the exit area of the shaping die in a certain range. Even if it does, the inner surface of the porous body will not be scratched and scratched, and the formation of the lubricating film will be stabilized. In addition, as described above, by making the opening area of the porous body wider than the exit area of the molding die within a certain range, the stepped position generated in the portion, that is, the auxiliary porous material at the exit portion of the molding die. It makes it easier to position the body.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of an extrusion molding apparatus of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the extrusion molding apparatus of the present invention.

FIG. 3 is a vertical sectional view showing another embodiment of the extrusion molding apparatus of the present invention.

FIG. 4 is an enlarged sectional view showing an expanded state of a crosslinkable resin material.

FIG. 5 is a graph measuring the ballast effect by a flow tester.

FIG. 6 is a vertical sectional view showing still another embodiment of the extrusion molding apparatus of the present invention.

FIG. 7 is a vertical sectional view showing still another embodiment of the extrusion molding apparatus of the present invention.

FIG. 8 is a vertical sectional view showing still another embodiment of the extrusion molding apparatus of the present invention.

FIG. 9 is a vertical cross-sectional view showing a conventional example of an extrusion molding apparatus.

[Explanation of symbols]

21, 31, 41, 71, 81, 91 Extruder 22, 32, 42, 72, 82, 92 Imposition mold 24, 34, 44, 74, 84, 94 Die device 24a, 34a, 54a, 74a, 84a , 94a, 9
4b Long land portion 25, 35, 45, 75, 85, 94a, 94b Porous body 26, 36, 46, 96a, 96b Lubricant reservoir portion 27, 37, 47, 79, 87, 97a, 97b Introduction of lubricant Department

Claims (7)

[Claims] 1. A method for producing an extrusion-molded article in which a crosslinkable resin material is extruded from a shaping die to a long land portion of a die device, wherein the crosslinkable resin material passing through the long land portion is porous all around. A method for producing an extruded product, which comprises extruding a crosslinkable resin material while supplying a lubricant through the body. 2. The extrusion according to claim 1, wherein the auxiliary lubricant is supplied from the inlet of the crosslinkable resin material into the inside of the porous body to the inner peripheral surface of the porous body through the auxiliary porous body. Molded article manufacturing method. 3. A chamber close to the inlet of the crosslinkable resin material and another chamber through a porous body over the entire circumference of the crosslinkable resin material passing through a long land portion divided into at least two stages of chambers. The method for producing an extruded product according to claim 1, wherein the crosslinkable resin material is extruded while supplying a larger amount of the lubricant. 4. An extruder for a crosslinkable resin material, a shaping die provided on the exit side of the extruder, and a die device provided on the exit side of the shaping die and having a long land portion. Be prepared,
Further, the porous body is concentrically provided in the long land portion, and the passage portion outside the porous body is used as a lubricant reservoir,
An apparatus for manufacturing an extruded product, characterized in that the reservoir communicates with a lubricant introduction port formed in a long land. 5. The apparatus for producing an extrusion-molded article according to claim 4, wherein the porous body has a porosity of 10 to 40% and a pore diameter of 0.1 to 10 μm. 6. The porous body has an outlet area which is 1.2 to 2.0 times as large as the outlet area of a molding die for molding the crosslinkable resin material. Manufacturing equipment for extruded products. 7. A long land portion divided into at least two stages of chambers is provided.
An apparatus for manufacturing an extrusion-molded article according to any one of claims.