JP3212377B2 - Manufacturing method and manufacturing apparatus for extruded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an extruded product by extruding a crosslinkable resin into a die device having a long land, and a production apparatus used for the method for producing the extruded product.

[0002]

2. Description of the Related Art Conventionally, as a method of continuously extruding a crosslinkable resin material, there has been known a method of shaping and heating using a die device having a long land portion. For example, Japanese Patent Application Laid-Open No. 48-96656 discloses that a crosslinkable resin material is heated and vulcanized by using a die device having a long land portion which forms a vulcanizable resin composition and vulcanizes by heating. Is disclosed.

In this method, the temperature and length of the long land are determined so that the cross-linking reaction of the cross-linkable resin material passing therethrough is completed, and a molded product cross-linked from the land outlet is continuously obtained. is there. In this method, a high back pressure is applied to the plasticizing zone of the crosslinkable molding material due to the presence of the long land portion in the molding process, so that the inner wall of the long land and the molding passing therethrough are formed. There is a method in which a lubricant is supplied to an interface with a material or a molded product to reduce 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 so that it can be molded continuously and satisfactorily, an optimum amount of lubricant is uniformly distributed on the outer surface of the crosslinked resin material to be extruded, and stable. It is necessary to form a lubricating film. In the conventional extrusion molding apparatus, as shown in FIG. 9, two flanges (d) and (d) are provided between an extruder (a) and a die device (c) having a long land (b). Flange (d)
(D) A thin metal foil of required shape (f) between the opposing surfaces of (d)
By inserting the two flanges (d) and (d) with bolts, etc., the resin passage (g) is placed inside the metal foil (f).
A slit (h) was provided radially. The lubricant is continuously or discontinuously press-fitted by a pump or other means from the lubricant introduction port (i) leading to the slit (h), so that the cross-linkable resin material passing through the resin passage (g) is formed. A method of supplying a lubricant to the outer surface has been adopted.

[0005]

However, in order to maintain an ideal lubricating state, it is not always easy to supply the lubricant stably. In the case of supplying the lubricant by the slit (h), There is a problem that the supply stability is affected by the slit (h) interval and the parallelism of the opposing surfaces on both sides of the slit. That is, when the lubricant is supplied from the lubricant inlet port (i) and 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 surface forming the slit. However, there is a risk that the lubricant may partially 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 the lubricant and unstable supply of the lubricant easily causes a lubrication film formed between the crosslinkable resin material and the inner surface of the long land portion (b) to break, and therefore, the surface of the molded product is reduced. In addition to scratching, the quality and commercial value of the molded product are reduced, and the ejection is changed due to film shortage, which makes it difficult to secure stable productivity. Therefore, it is an important technical problem to prevent the drift of the lubricant and to stably supply the lubricant.

In the method using a liquid lubricant, it is necessary to wash the lubricant attached to the surface of the molded article in the next step. In addition, depending on the type of the lubricant used, cleaning is difficult, and the lubricant remains in the molded product, resulting in 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 also 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 extruding and molding a resin material using a die device having a long land portion, in which a lubricant is prevented from drifting and a lubricant is stably supplied. Is to do.

Another object of the present invention is to provide a method for producing an extruded product using a long land die, wherein the extruded product is produced using a 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]

According to the present invention, there is provided a method for manufacturing an extruded product, comprising: extruding a crosslinkable resin material from a molding die to a long land portion of a die device; The crosslinkable resin material is extruded while supplying a lubricant through the porous body over the entire circumference of the crosslinkable resin material.

[0011] The method for producing an extruded product according to the second aspect of the present invention is the method for producing an extruded product according to the above-mentioned method of the present invention, wherein the crosslinkable resin material enters the inside of the porous body through the auxiliary porous body to the inner peripheral surface of the porous body. Supplies an auxiliary lubricant.

The method for producing an extruded product according to the third aspect of the present invention is the same as the method of the present invention or the second aspect, except that at least
A larger amount of lubricant is supplied to the chamber near the inlet of the crosslinkable resin material than the other chambers through the porous body over the entire circumference of the crosslinkable resin material that passes through the long land divided into the step chambers The cross-linkable resin material is extrusion-molded while performing.

[0013] The manufacturing apparatus used in the manufacturing method of the present invention comprises:
An extruder for a crosslinkable resin material, a molding die provided on the exit side of the extruder, and a die device provided on the exit side of the molding die and having a long land portion, A porous body was provided in the long land to cover the passage of the crosslinkable resin material, and the passage outside the porous body was used as a reservoir for the lubricant, and the reservoir was formed in the long land. It is configured to communicate with the lubricant inlet.

Further, in the manufacturing apparatus used in the manufacturing method of the present invention 2, the auxiliary porous body is provided on the cross-linkable resin material inlet side of the porous body in order to make the extrusion of the cross-linkable resin material more stable. Things.

The manufacturing apparatus used in the manufacturing method according to the third aspect of the present invention has a long land portion divided into at least two stages of chambers, and each chamber can supply a lubricant at a different flow rate. It is.

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

In order to control the gas permeation amount, it is important to select a porous body. Generally, the porosity, the pore diameter, and the thickness determine the gas permeation amount of the porous body. Regarding the thickness, since there is a restriction on the mold structure and a restriction on the production of the porous body, the thickness cannot be extremely increased, and the strength cannot be reduced so much.
More preferably, it is 0.5 to 2 cm.

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

In any of the manufacturing apparatuses of the present invention, the opening area of the porous body should be 1.2 to 2.0 times the exit area of the molding die for molding the crosslinkable resin material. preferable.

In the method for producing an extruded product according to the third aspect of the present invention, at least 2
A larger amount of lubricant is supplied to the chamber near the inlet of the crosslinkable resin material than the other chambers through the porous body over the entire circumference of the crosslinkable resin material that passes through the long land divided into the step chambers The cross-linkable resin material is extrusion-molded while performing. The cross-sectional shape of the resin passage formed by the porous body in any of the above manufacturing apparatuses is not particularly limited, and may be, for example, a cylindrical shape, a slit shape, a rectangular shape, a corrugated shape. , U-shaped,
It may be a deformed shape such as a corrugated plate. Furthermore, the cross-sectional shape may correspond 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 hardly occur at the molding temperature of the resin used.
Further, a chemically stable substance which does not melt in the resin and does not promote deterioration of the resin is preferable. For example, examples of the lubricant satisfying such conditions include liquid polysiloxane (polydimethylsiloxane, polymethylsiloxane, etc.), polyhydric alcohols such as ethylene glycol, and their alkyl esters, alkyl ethers, and polyoxyalkylenes. And alkyl esters thereof, alkyl ethers, polyoxyalkylenes, and copolymers of two or more alkylene oxides thereof. Among them, a water-soluble surfactant such as polyhydric alcohol which is easily removed after adhering to the surface of the molded article is preferable.

The gaseous 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. However, in order to prevent the lubricant from remaining in the obtained molded product, a gas lubricant may be used. Is preferred.

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

(Heating Method) The length of the long land is determined by the cross-linkable resin molding material used and the inner diameter or thickness of the molded product. The heating method for accelerating the crosslinking reaction is generally arbitrary, but is most simple and easy to control the heating conditions by electric heating. The temperature condition does not need to be the same over the entire length of the long land portion, but is preferably divided into several zones and set so as to be the most suitable temperature condition and heating time 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. There are also crosslinkable thermoplastic resins containing a crosslinker, and natural or synthetic rubbers.

The thermoplastic resin includes, for example, polyethylene, polystyrene, polypropylene, polyvinyl chloride,
Nylon, or a copolymer such as an ethylene-propylene copolymer or an ethylene-vinyl acetate copolymer, and a mixture of two or more of these. Further, additives such as synthetic rubber, paraffin, different kinds 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, for example, a methylol acrylamide polymer, a carboxylic acid polymer containing a metal oxide, and an unsaturated polyester can be used.

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

The amount of the crosslinking agent used depends on the molecular structure of the thermoplastic resin used, such as the molecular weight, molecular weight distribution, the number of branches, and the like.
It is necessary to determine according to the decomposition temperature of the crosslinking agent and the required degree of crosslinking, 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 crosslinked resin material to be extruded. The lubricant pressure for stable lubricant supply can be freely set by selecting the pore diameter, porosity and thickness (perpendicular to the flow direction of the molding material) of the porous body. . Furthermore, by increasing the length of the porous body (parallel to the flow direction of the molding material), 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 transformed into

Further, in the manufacturing apparatus of the present invention in which the porous body is provided on the long land portion of the die device, when gas is used as the lubricant, the entire peripheral surface of the crosslinkable resin material in the long land portion. Then, the gas uniformly contacts through 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 with a lubricating thin film formed on the entire surface, the surface of the extruded crosslinkable resin material is not damaged.

When the porous body and the auxiliary porous body are 10 to 4
In the case of having a porosity of 0% and a pore diameter of 0.1 to 10 μm, an appropriate gas permeation amount of each porous body can easily be in a range of 0.5 to ²⁰ cm ³ / cm ² sec per unit area of permeation. Can be maintained. When the gas permeation amount of the porous body is 0.5 cm ³ / cm ² sec or less, the cross-linking property of the gaseous lubricant caused by the fluctuation of the extrusion state of the cross-linkable resin material and the uneven flow of the gas lubricant caused by the 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 amount of the porous body is 20 cm ³ / cm ² sec or more, the molded article vibrates due to the uneven flow of the gas flow due to the resin flow rate, and when this vibration occurs, the molded article moves to the inner wall of the porous body. Is repeatedly attached and detached, which causes damage to the surface of the molded article.

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 molding die for molding the crosslinkable resin material, the extruded resin material is porous from the molding die. When extruded into the porous body, the isotropic pressure received by the molding die is released in the porous body, so that the crosslinkable resin material expands. At this time, since the opening area of the porous body is larger than the exit area of the molding die, the crosslinkable resin material swells in a conical shape expanding from the entrance to the exit of the porous body, and the crosslinkable resin material and the porous body There is a gap between the inner surfaces of the two. Lubricant stays in this gap to promote the formation of a lubricating film, especially at the entrance 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 functions as a cushion for the crosslinked resin material molded product. However, if the opening area of the porous body exceeds 2.0 times the exit area of the molding die, the gap between the crosslinkable resin material and the inner surface of the porous body is 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 molding die for molding the crosslinkable resin material, as described above, the auxiliary porous material is provided at the entrance of the crosslinkable resin material of the porous body. The body can be easily arranged. By supplying the auxiliary gas to the inner peripheral surface of the porous body, the auxiliary gas is press-fitted from the base portion of the crosslinkable resin material that expands in a parabolic shape due to the ballast effect, and this auxiliary gas causes the vicinity of the entrance of the porous body Since the formation of a lubricating film on the surface of the crosslinkable resin material which is easily adhered to the surface is promoted, the adhesion is prevented.

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

[0035]

EXAMPLES Examples of a method and an apparatus for manufacturing an extruded product using a 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, on an extruder (21) for a crosslinkable resin material and on an outlet side of the extruder (21). Shaped mold
(22) and a die device (24) provided on the outlet (22b) side of the molding die (22) and having a long land portion (24a),
Further, a cylindrical porous body (25) is provided concentrically within the long land (24a), and a passage portion outside the porous body (25) is used as a lubricant reservoir (26), and the reservoir is formed. Part (26) is a long land part
It communicates with the lubricant inlet (27) formed in (24a).

In the case of extrusion molding using the above-described production apparatus using a gas as a lubricant, first, a resin material containing a crosslinking agent in advance is extruded into a molding die (22) by an extruder (21), and is elongated. It passes through the porous body (25) of the land (24a).
The porous body (25) is a resin passage / gas supply part, and when a gas is press-fitted from a lubricant inlet (27) by a pump or other means, this is a pool part outside the porous body (25). After flowing into (26), it passes through the porous body (25) and contacts 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 the long land (24
The crosslinkable resin material is crosslinked by the heating of a).

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

Using nitrogen gas as a lubricant, the inlet (27)
And a nitrogen gas was continuously supplied at a pressure of 1 kg / cm ² and 3.0 cm ³ / cm ² sec. The cross-linkable resin material that has passed through the porous body (25) and has been lubricated has a length of one at the long land (24a).
It was heated at 60 ° C. for 3 minutes and extruded outside. The molded article according to the present example has a diameter of 14.8 mm and a gel fraction of about 25.
%, A bar-shaped molded product having a smooth surface.

<Comparative Example 1> Polyoxyethylene-propylene copolymer (manufactured by Nissan Unilube Co., Ltd.) was used as a lubricant by a conventional slit method (slit thickness: 80 μm) instead of the cylindrical porous body (25). (50MB-26X). Other conditions were the same as in Example 4 above. 5 polyoxyethylene-propylene copolymer
The molded product coming out of the die was supplied in a water tank at a rate of cc / min and washed.

The obtained molded product was a rod-shaped molded product having a gel fraction 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 again with a cloth.

<Example 3> Another example of a method for producing an extruded product using the extrusion molding 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 15 mm. Next, low-density polyethylene (manufactured by 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 blended with 5 parts by weight was extruded at an extrusion rate of 5 kg / h. At this time, the supply amount of nitrogen gas is
2.0 cm ³ / cm ² sec per unit transmission area of (25).
The resin temperature of the molding die was 125 ° C.

The crosslinkable resin material is a long land (24a)
The mixture was heated at 160 ° C. for 3 minutes and extruded to the outside. The molded product according to the present example was a rod-shaped molded product having a diameter of 14.8 mm. In addition, the supply amount of the gas was considered as 10 cm ³ / cm ² sec per unit transmission area of the porous body (25), but the vibration of the molding resin was smaller in the case of 2.0 cm ³ / cm ² sec. And the non-variability of ejection was excellent. Further, the supply amount of the gas is 0.3 cm ³ / cm per unit transmission area of the porous body (25).
^{Although it was set to 2} sec, the above 2.0 cm ³ / cm ² sec showed better gas lubricating action.

<Embodiment 4> FIG. 2 shows another embodiment of the extrusion molding apparatus according to the present invention, in which an extruder (31), a molding die (molding region) (32) and the inside thereof are passed through. A die (lubricating cross-linking region) (34) having a long land portion (34a) having a length and temperature at which the cross-linking reaction of the cross-linkable resin molding material is substantially completed;
A cylindrical porous body (35) is provided concentrically inside the long land (34a). In this embodiment, the porous body
The opening diameter (R) of (35) is equal to the diameter of the outlet (32a) of the molding die (32).
It is designed to be three 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).
After the liquid lubricant is pressed into the reservoir (36) from the inlet (37), it passes through the porous body (35) and is supplied to the entire periphery of the crosslinkable resin material.

At this time, as shown in FIG. 4, the crosslinkable resin material (P) is formed by a forming mold (32), and then the porous body (3) is formed.
Extruded to 5). At this time, the crosslinkable resin material that has been subjected to isotropic pressure from the molding die (32) expands in a conical shape (ballistic effect) due to the release of pressure in the porous body (35). )
By setting the opening diameter (R) of the cross-linkable resin material in advance to a diameter corresponding to the amount of expansion, molding can be performed without the cross-linkable resin material being rubbed on the inner wall surface of the porous body (35). Therefore, the surface of the extruded product becomes smoother. In this case, on the inlet side of the porous body (35), a wider gap (S) is formed between the pressure-releasing pressure and the root portion of the crosslinkable resin material (P) that has expanded in a conical shape, and a lubricant is formed in this portion. Is supplied more, lubrication is promoted particularly on the inlet side of the porous body, which tends to damage the molded article.

<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 portion (47) is provided on the lower surface of the long land portion (44a), and communicates with the reservoir portion (46). In the present embodiment, the opening diameter (R) of the porous body (45) is a shaping mold (42).
1.4 times the diameter of the exit (42a) of the
Times).

The expansion amount (ballast effect) of the cross-linkable resin material, as shown in FIG. 4, increases with the shear rate of the extrudate, and increases the flow path length (L) of the shaping zone and its diameter (D). ) And L
The smaller the value of / D, the smaller the value. The ballast effect was measured with a flow tester for those having various shear rates and L / D. The result was about 1.5 times as shown in FIG. Therefore, it is considered that the opening diameter of the porous body (45) and the exit diameter of the molding die (42) should be about 1.5 times in the apparatus of the above embodiment. However, the actual extrusion flow state is different from the flow tester, and the actual expansion amount is slightly larger than the measured value because the resin is stretched in the extrusion direction by the take-off machine and the resin is dragged in the flow direction by the viscosity of the lubricant. It can be said low. When L / D exceeds 1.5 times, the porous body (45)
The gap between the resin and the crosslinkable resin material is too large, and the heating efficiency in this portion is deteriorated. On the other hand, if the L / D is too small, the molded article is rubbed on the inner wall of the porous body, so that the molded article is damaged. Therefore, it is preferable that L / D is in the range of 1.1 to 1.5, preferably 1.1 to 1.3.

<Example 6> An example of a manufacturing method using the apparatus for manufacturing an extruded product shown in FIG. 2 will be described. The extruder (31) has an inner diameter of 50 mm and an outlet (32a) of a molding die. Diameter φ1
The opening diameter (R) of the porous body (35) was 13 mm. Next, a resin material obtained by mixing 1.0 part by weight of a crosslinking agent (dicumyl peroxide) with 100 parts by weight of low-density polyethylene (manufactured by Sumitomo Chemical Co., trade name; high-pressure polyethylene G201) at an extrusion rate of about 5 kg / h. Extruded in quantity. The extruded crosslinkable material is shaped into a rod by a forming mold (32), and then passes through a porous body (35) for supplying a liquid lubricant. At this time, the resin temperature of the molding die was 125 ° C.

As a lubricant, a polyoxyethylene-propylene copolymer (manufactured by Nissan Unilube Co., trade name; 50)
MB-26X) was supplied at a rate of 5 cc / min from a lubricant inlet (37) via a supply pump. The long land (34a) was heated at 160 ° C. for 3 minutes and extruded outside. The molded product obtained in this example had a diameter of 12.7 mm and a gel fraction of 3
With a rod-shaped compact having a surface smoothness of 0%, it was possible to continuously and stably mold without fluctuation of discharge.

When the diameter of the outlet (32a) of the molding die and the diameter of the opening (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 diameter of the outlet (32a) of the molding die is 10 mm,
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 according to the present invention. The entire structure is the same as that of the above-described embodiment. In this embodiment, a long land portion (74a ), The opening diameter (R) of the cylindrical porous body (75) is made larger than the diameter of the outlet (72a) of the molding die (72), and the molding die (72) and the porous body (75).
An auxiliary porous body (78) is provided in a step portion resulting from the difference in diameter between the auxiliary porous body (78). The auxiliary porous body (78) is a dedicated gas inlet
(79).

<Embodiment 8> The apparatus for manufacturing an extruded product shown in FIG. 7 is a modified example of the apparatus for manufacturing an extruded product according to the embodiment 7, and includes a molding die (82) and a long land portion (84a). Cylindrical porous body (85)
The auxiliary porous body (88) is made longer when the stepped portion caused by the difference in the opening diameter from the above is small.

<Embodiment 9> The manufacturing apparatus of Embodiment 7 was used.
As an example of the production method, the outlet diameter of the extruder (71) is set to φ5.
0 mm, and the diameter of the exit (72a) of the molding die (72) is φ10 m.
m, the opening diameter (R) of the porous body (75) in the long land (74a)
φ13 mm. Next, low-density polyethylene (Sumitomo Chemical
Manufactured by Gakusha, trade name; high-pressure polyethylene G201) 100
1.0 part by weight of crosslinking agent (dicumyl peroxide) in parts by weight
Extrusion of resin material containing 5 parts by weight at an extrusion rate of 5 kg / h
Was. Further, the supply amount of nitrogen gas from the porous body (75) is 3.0.
cm^Three/cm ^TwoIn seconds, supply to the entire outer surface of the crosslinkable resin material
The gas supply amount from the auxiliary porous body (78) is 3.0 cm.^Three/cm^Twos
It was supplied to the inner peripheral surface of the porous body (75) by ec. Long land (7
In 4a), heating is performed at 160 ° C for 3 minutes, and the resin is
Extruded. The rod-shaped molded product according to the present embodiment has a diameter of 12.
7 mm, which is suitable for the porous body (75) of the long land (74a).
Molding was smooth with no resin adhesion.

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

The vibration of the resin at the time of extrusion molding was further reduced as compared with Example 9, and the resin did not adhere to the porous body (75).

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

<Embodiment 12> The manufacturing apparatus of Embodiment 11 is used.
To describe an example of the manufacturing method used, the inner diameter of the extruder (91) was φ
The width of the outlet (92a) of the molding die is 200
mm, thickness 5mm, long land part divided into two steps
The length of the first chamber (94a) is 100 mm,
The length of the chamber (94b) is 600 mm, the porous body (95a),
The opening of (95b) was 220 mm in width and 7 mm in thickness. Next
Low-density polyethylene (manufactured by Sumitomo Chemical Co., Ltd .; trade name; high pressure
Method polyethylene G201) 100 parts by weight of a crosslinking agent (dic
Resin material containing 1.0 part by weight of
The extrudate was extruded at an output of about 5 kg / h. Also, the first channel
The nitrogen gas supply from the porous body (95a) was reduced to 40
cm^Three/cm^TwoIn sec, the porous material (95b) is transferred to the second chamber.
7 cm of nitrogen gas supply ^Three/cm^TwoCrosslinkable resin material outer surface in sec
The whole surface was supplied. At this time, it was connected to the extruder (91) outlet
The resin temperature of the molding die (92) was 125 ° C. Extruded
The crosslinkable material was molded into a rod shape by the molding die (92)
After that, it passed through a porous body (95) for supplying a gaseous lubricant.
Heat at 150 ° C for 5 minutes for long land (94a) and (94b)
The molded product obtained by extruding the resin to the outside has a width of 18
0mm, thickness 60mm, good surface properties with gel fraction 45%
Molded product.

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

[0059]

According to the present invention, the crosslinkable resin material extruded from the extruder is uniformly dispersed in the lubricant over 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 deviation of the parallelism of the opposing surfaces of the slit, which occurs at the time of setting the mold as in the conventional case of supplying the lubricant from the slit, is completely eliminated, and the drift of the lubricant can be eliminated.

In the present invention, by providing the auxiliary porous body on the inlet side of the porous body, the formation of a lubricating film on the outer peripheral surface of the crosslinkable resin material is further promoted, and the surface of the extruded product is free from scratches and the like. Molding can be performed more reliably. Further, the long land portion is divided into at least two-stage chambers, and the porous resin is passed through the entire circumference of the crosslinkable resin material through the porous body into the chamber close to the entrance of the crosslinkable resin material, and the larger amount than the other chambers. By supplying the lubricant, it is possible to prevent the resin generated at the initial stage of extrusion from adhering to the mold surface, and it is possible to stably mold even a sheet-like molded product.

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

Further, in the extrusion molding apparatus of the present invention, the cross-linkable resin material extruded from the molding die is expanded by increasing the opening area of the porous body within a certain range from the exit area of the molding die. Even if it does, there is no possibility that the inner surface of the porous body will be rubbed and damaged, and the formation of the lubricating film will be stabilized. In addition, as described above, by setting the opening area of the porous body to be larger than the exit area of the molding die within a certain range, the step position generated in the portion, that is, the auxiliary porous material is formed at the exit portion of the molding die. It is easier to place the body.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal 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 showing measurement of a ballast effect by a flow tester.

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

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

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

FIG. 9 is a longitudinal 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 Molding die 24, 34, 44, 74, 84, 94 Die unit 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 27, 37, 47, 79, 87, 97a, 97b Lubricant introduction Department

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-83779 (JP, A) JP-A-59-164110 (JP, A) JP-A-50-83781 (JP, A) JP-A-62 JP-A-1-202419 (JP, A) JP-A-50-96889 (JP, A) JP-A-6-23822 (JP, A) JP-A-4-89318 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (7)

(57) [Claims] 1. A method of manufacturing an extruded product in which a crosslinkable resin material is extruded from a molding die to a long land portion of a die device, wherein a porous material is formed over the entire circumference of the crosslinkable resin material passing through the long land portion. A method for producing an extruded product, comprising extruding a crosslinkable resin material while supplying a lubricant through a body. 2. The extrusion method according to claim 1, wherein an auxiliary lubricant is supplied from an 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. Manufacturing method of molded article. 3. A chamber close to an inlet of the crosslinkable resin material, through a porous body over the entire circumference of the crosslinkable resin material passing through the long land portion divided into at least two stages of chambers, and another chamber. 3. The method according to claim 1, wherein the crosslinkable resin material is extruded while supplying a larger amount of lubricant. 4. An extruder for a crosslinkable resin material, a molding die provided on the outlet side of the extruder, and a die device provided on the outlet side of the molding die and having a long land portion. Be prepared
Further, the porous body is provided concentrically 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, wherein the reservoir communicates with a lubricant inlet formed in a long land. 5. The apparatus 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 having an exit area of 1.2 to 2.0 times the exit area of a molding die for molding a crosslinkable resin material. Extruded product manufacturing equipment. 7. A long land portion divided into at least two stages of chambers.
An apparatus for producing an extruded product according to any one of the preceding claims.