JP2002052607A - Method and mold for continuously manufacturing oriented product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a mold for continuously manufacturing an oriented product capable of easily performing the stretching of a high density resin in a high draw ratio at the time of extrusion molding, and capable of continuously obtaining the oriented product certainly stretched in an aimed draw ratio. SOLUTION: The method for continuously manufacturing the oriented product has a stretching process for shaping a raw material resin composition containing a thermoplastic resin, supplied into a mold under pressure into an almost molded product shape, while orienting the same at least in one orientation direction in a molten state and supplying a lubricant to the interface of the raw resin composition supplied into the mold and a molding surface. The lubricant is supplied until the raw resin composition reaches the stretching process after it becomes a developed state so as to come into close contact with the wall surface of the mold over the almost entire periphery thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing an oriented product and a mold for continuously producing an oriented product aiming at increasing strength and elastic modulus.

[0002]

2. Description of the Related Art A method for manufacturing an oriented product in which a resin is stretched during molding for the purpose of enhancing strength has already been disclosed in Japanese Patent Publication No. Hei.
No. 58093. That is, the method for producing an oriented product disclosed in Japanese Patent Publication No. 2-58093 is a method of pushing the product into the enlarged-diameter portion by the extrusion pressure, and since there is no need for a drawing force, the orientation control is highly arbitrarily performed. Excellent controllability and productivity.

[0003]

However, in the case of this manufacturing method, the film is stretched at a temperature not lower than the glass transition temperature but not higher than the melting point. It is sudden. Therefore, in order to achieve uniform stretching, it is necessary to make the resin temperature distribution uniform, but it is not possible to achieve uniform temperature in thick products or high-speed molding. That is, there is a problem in the moldability of thick-walled products and high-speed molding. In addition, since the elastic modulus is also at a high level in this temperature range, the necessary extrusion pressure is high, and it is impossible to continuously achieve high-viscosity resin or high-magnification stretching with an extruder. Therefore, in order to enable high-density resin or high-magnification stretching, a lubricant is supplied so as to be applied to the interface between the resin and the resin contact surface of the mold.

However, in the above manufacturing method, the position where the lubricant is supplied is not taken into consideration, and the raw resin composition supplied into the mold before expanding the diameter of the resin is substantially equal to the entirety of the wall surface in the mold. Lubricants were sometimes supplied even before being developed so as to be in close contact with the circumference. As described above, the lubricant adheres to the resin at a stage before the raw resin composition supplied into the mold before expanding the diameter of the resin is developed so as to be in close contact with the entire circumference of the wall surface in the mold. If this is done, the contact pressure of the resin on the mold surface becomes zero, and the raw resin composition is stretched without being filled in the mold, so that it is possible to obtain an oriented product having a desired stretching ratio. There is a problem of disappearing.

In view of the above, the present invention has been made in view of the above-mentioned problems, and when performing extrusion molding, it is possible to easily perform high-density resin or high-magnification stretching, and to surely achieve orientation with a desired stretching ratio. An object of the present invention is to provide a method for continuously producing an oriented product and a mold for continuously producing an oriented product that can continuously produce products.

[0006]

In order to achieve such an object, a method for continuously producing an oriented product according to the first aspect of the present invention (hereinafter referred to as "a method for producing the first aspect"). ) Is at least 1% in a molten state of the raw material resin composition containing the thermoplastic resin which has been fed into the mold by pressure.
An orientation step of forming a substantially molded article while orienting in an orientation direction equal to or more than the axis, and supplying a lubricant to an interface between a raw resin composition supplied into the mold and a mold surface. In the continuous production method of the product, the raw resin composition supplied into the mold is substantially unfolded so as to be in close contact with the entire circumference of the wall surface in the mold, and then lubricated until the stretching step is reached. The composition is characterized in that an agent is supplied.

Further, a continuous production method of an oriented product according to the second aspect of the present invention (hereinafter referred to as “the production method of the second aspect”) is in addition to the configuration of the first aspect. Before the stretching step, a configuration was provided in which a crosslinking step of crosslinking the thermoplastic resin was provided. In addition, the continuous production method for an oriented product according to the invention described in claim 3 of the present invention (hereinafter referred to as “the production method of claim 3”) is based on the raw material resin in addition to the constitution described in claim 2. The composition was such that a thermal crosslinking agent was contained in the composition to perform thermal crosslinking.

[0008] A method for continuously producing an oriented product according to the invention as set forth in claim 4 of the present invention (hereinafter referred to as a "production method of claim 4") is any one of claims 1 to 3. And the thermoplastic resin is a crystalline thermoplastic resin.

A continuous production mold for an oriented product according to the invention of claim 5 of the present invention is a mold in which a raw material resin composition containing a thermoplastic resin which is fed into a mold by pressure is melted. A stretching zone for shaping into a substantially molded product shape while orienting in at least one axis orientation direction, and applying a lubricant to the interface between the raw resin composition supplied into the mold and the mold surface in the mold. In a continuous production mold of an oriented product provided with a lubricant supply path to be supplied, the raw resin composition supplied into the mold until the outlet of the lubricant supply path reaches the stretching zone is substantially a mold. The configuration is provided after the position where it is deployed so as to be in close contact with the entire circumference of the inner wall surface.

The thermoplastic resin used in the present invention is not particularly limited. Examples thereof include polyolefin resin, polystyrene, polyvinyl chloride, polymethyl methacrylate, polycarbonate, and polyester. These can be used alone or in combination. . In particular, it is preferable to use a crystalline thermoplastic resin as in the production method of the fourth aspect.

[0011] As the crystalline thermoplastic resin, L-LDP
E (linear low density polyethylene), LDPE (low density polyethylene), MDPE (medium density polyethylene), HD
Polyethylene such as PE (high density polyethylene), polypropylene such as random PP (polypropylene), homo PP (polypropylene), block PP (polypropylene), polyamide, polybutylene terephthalate, polyoxymethylene, polyphenylene sulfide, ethylene propylene diene, etc. No.

Further, in the manufacturing method of the first aspect, it is preferable that the shaped article formed into a substantially molded article shape by the stretching step is cooled to an orientation relaxation temperature or lower. Here, "below the orientation relaxation temperature" means a glass transition temperature or less in the case of an amorphous thermoplastic resin, and means a crystallization start temperature or less in the case of a crystalline thermoplastic resin. That is, the cooling is performed to cool the stretched shaped article and freeze the orientation.

In the production method of the second aspect, the method of crosslinking the raw resin composition in the crosslinking step is not particularly limited. For example, general means such as electron beam, ultraviolet ray, hot water crosslinking, and thermal crosslinking can be used. Just use it. However, when cross-linking thick products, thermal cross-linking is the most effective in the case of electron beams or ultraviolet rays because the transmission capacity of the radiation source is low, and in the case of hot water cross-linking, the penetration rate of hot water is slow. .

In the production method of the third aspect, the thermal crosslinking agent is not particularly limited, but an organic peroxide can be used, and the thermal crosslinking agent may be appropriately selected from the viewpoint of the molding temperature and compatibility of the thermoplastic resin used. You can choose, specifically,
Dicumyl peroxide, α, α'-bis (t-butylperoxy-m-isopropyl) benzene, cyclohexane peroxide, 1,1-di (t-butylperoxy) cyclohexane, 1,1-di (t- Butylperoxy) 3,3,5-trimethylcyclohexane, 2,2-
Di (t-butylperoxy) octane, n-butyl-
4,4-di (t-butylperoxy) vererate, di-
t-butyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, cumylperoxy neodecate, t
-Butyl peroxybenzoate, 2,5-dimethyl-
2,5-di (benzoylperoxy) hexane, t-butylperoxyisopropyl carbonate, t-butylperoxyallyl carbonate, t-butylperacetate, 2,2-bis (t-butylperoxy) butane,
Di-t-butylperoxyisophthalate, t-butylperoxymaleic acid, diazoaminobenzene, N, N
'-Dichloroazodicarbonamide, trichloropentadiene, trichloromethanesulfochloride, methyl ethyl ketone peroxide and the like, and dicumyl peroxide, α, α'-bis (t-butylperoxy-
m-Isopropyl) benzene, t-butylcumyl peroxide, benzoyl peroxide, t-butylperoxybenzoate and methyl ethyl ketone peroxide are preferred, and dicumyl peroxide, α, α'-bis (t-butylperoxy-m- (Isopropyl) benzenemethylethylketone peroxide is more preferred.

In the production method of the present invention, the degree of cross-linking of the cross-linked resin is limited to 5% or more and 70% or less because, when the degree of cross-linking is less than 5%, the molecular chain is stretched at a temperature not lower than the melting point. This is because, if it passes through and exceeds 70%, the elongation of the resin is reduced, and there is a possibility that high-magnification stretching may not be performed. In the present invention, the degree of crosslinking is JIS K67.
It can be represented by a gel fraction (%) represented by the following formula in accordance with No. 69.

[0016]

(Equation 1)

In the above formula, the weight of the sample after the solvent extraction means that the uncrosslinked resin remaining in the sample is dissolved using a solvent capable of dissolving the selected uncrosslinked thermoplastic resin. , The weight of only the remaining insoluble matter.

As a method of supplying the raw material resin composition into the mold, there is a method of pressure-feeding using a pressure pump capable of continuously applying heat to the thermoplastic resin. As such a pressure pump, a method using an extruder is most preferably used.

As the extruder, a single-screw extruder, a twin-screw extruder, a multi-screw extruder and the like can be used, but as in the production method of claim 3, the raw resin composition contains a thermal crosslinking agent. If it is, melt the thermoplastic resin among them, using a twin-screw co-rotating extruder that is excellent in mixing ability with the thermal crosslinking agent, the thermoplastic resin and the thermal crosslinking agent in this extruder Is preferably kneaded.

The shape of the obtained oriented product is not particularly limited, and it is possible to select not only pipes and sheets, but also complicated shapes capable of forming an H-shaped or rain gutter or the like. Examples of the lubricant to be supplied to the contact surface of the raw material resin composition of the mold include ethylene oligomer, silicone oil, stearic acid, polyethylene glycol, liquid paraffin, and a low melting point polymer. Considering the properties, polyethylene glycol is preferred.

Further, as a method of supplying the lubricant to the resin contact surface, at least a portion to be the resin contact surface of the mold is formed of a porous material, and pressure is applied to the lubricant from the back side of the porous material. A method of oozing out toward the surface of the resin contact surface, a method of developing a lubricant with a manifold and supplying it to the shape of a molded product are exemplified. The device for supplying the lubricant is not particularly limited as long as the lubricant can be supplied against the pressure in the mold, and examples thereof include a plunger pump and a diaphragm pump.

The lubricant is supplied at a position after the raw resin composition supplied into the mold is spread so as to be in close contact with the entire periphery of the mold, that is, before the lubricant is stretched and oriented. There is no particular limitation as long as the raw material resin composition is evenly distributed over the clearance portion in the mold, but it is preferable to supply the lubricant as much as possible in the forward direction of the resin in the mold.

In the continuous production method of the present invention, the stretching is performed by enlarging the width and reducing the thickness when the molded article is a sheet, and by increasing the inner diameter and decreasing the thickness when the molded article is a pipe. Uniaxial stretching can be achieved by one or more functions. The stretching ratio can be arbitrarily controlled depending on the magnitude of these actions, and is selected from the range of 5 times or more and 50 times or less in the area reduction rate at which the stretching effect is exhibited.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a manufacturing apparatus used for continuously manufacturing an oriented product of the present invention. As shown in FIG. 1, this manufacturing apparatus 1
A mold 2 and an extruder 3 are provided. Also, the mold 2
A mold body 21 and a mandrel 22 are provided.

The mold body 21 has a resin supply port 210 and a lubricant supply port 211 as shown in FIG. Further, a distribution zone forming cylinder 212, a reduced diameter cylinder 215, a small diameter cylinder 213, an enlarged diameter cylinder 216, and a large diameter cylinder 214 are formed in the direction in which the raw material resin composition is extruded. The resin supply port 210 is an inlet for supplying a kneaded product obtained by kneading a molten thermoplastic resin extruded from the extruder 3 and a thermal crosslinking agent. Lubricant supply port 21
1 is a thermal bridge zone 5 described later in the small-diameter cylindrical portion 213.
1 is provided at a position substantially at the center, and is configured to supply the lubricant pressure-fed by a pressure pump or the like to the inner peripheral surface of the small-diameter cylindrical portion 213 which is a resin contact surface. The distribution zone forming cylinder 212 is provided from the end on the resin supply port 210 side of the mold body 21 toward the center.
The small-diameter cylindrical portion 213 is provided at the center of the mold body 21, and is provided with the distribution zone forming cylindrical portion 212 and the small-diameter cylindrical portion 21.
Between the distribution zone forming cylinder 212 and the small-diameter cylinder 21.
3 is provided with a reduced diameter cylindrical portion 215 that gradually decreases in diameter. The large-diameter cylindrical portion 214 is provided from the mold outlet 217 side toward the center, and is provided between the small-diameter cylindrical portion 213 and the large-diameter cylindrical portion 214 from the small-diameter cylindrical portion 213 to the large-diameter cylindrical portion 2.
An enlarged-diameter tube portion 216 that gradually increases in diameter toward 14 is provided.

The mandrel 22 is provided with a lubricant supply passage 221 and a lubricant supply port 227, and has a distribution zone forming shaft 222, a reduced diameter shaft 225, Small diameter shaft 223, large diameter shaft 2
26, the large diameter shaft portion 224 is connected and formed.

The distribution zone forming shaft 222 is supported by the mold body 21 at a part of one end, and is provided with a resin supply port 210.
A helical groove (not shown) is formed in a portion extending from the portion facing to the outer peripheral surface of the portion extending to the reduced diameter shaft portion 225. Further, the diameter of the portion facing the reduced diameter shaft portion 225 of the distribution zone forming shaft portion 222 is slightly smaller than the diameter of the portion supported by the mold body 21, A clearance portion 222a is formed between them.

The small-diameter shaft portion 223 forms a small-diameter, thick-walled tube with the small-diameter cylindrical portion 213 of the mold body 21, and the large-diameter shaft portion 224 forms a large-diameter tube of the mold body 21. Tube part 2
14, the same cross-sectional shape as the cross-sectional shape of the tube to be formed is formed. In addition, a part of the large-diameter shaft portion 224 projects outside the mold outlet 217. The reduced diameter shaft portion 225 is gradually reduced in diameter from the distribution zone forming shaft portion 222 to the small diameter shaft portion 223, and the enlarged diameter shaft portion 226 is gradually reduced from the small diameter shaft portion 223 to the large diameter shaft portion 224. The diameter has been expanded.

The mold 2 having the above-described configuration is configured so that the reduced-diameter shaft portion 225 and the reduced-diameter cylindrical portion 21 are separated from the clearance 222a.
5, a flow rate adjustment zone 50 that adjusts a flow rate for distributing the resin supplied from the resin supply port 210 to the clearance between the small-diameter shaft portion 223 and the small-diameter cylindrical portion 213 over a substantially central portion of the clearance portion formed between the small-diameter shaft portion 223 and the small-diameter cylindrical portion 213. Are formed.

Further, from a substantially central portion of a clearance portion formed between the reduced diameter shaft portion 225 and the reduced diameter cylindrical portion 215 to a clearance portion formed between the small diameter shaft portion 223 and the small diameter cylindrical portion 213, A thermal crosslinking zone 51 for thermally crosslinking the distributed resin is formed. Further, in a clearance formed between the small-diameter shaft portion 223 and the small-diameter cylindrical portion 213, a cooling zone 52 for cooling and adjusting the resin thermally crosslinked in the thermal crosslinking zone 51 to a temperature at which it can be oriented is formed. Further, in a clearance formed between the enlarged diameter shaft portion 226 and the enlarged diameter cylindrical portion 216, the cooling zone 52 is provided.
A stretching zone 53 is formed in which the crosslinked resin that has passed through is stretched while being oriented to form an oriented body.

In the mandrel 22, a lubricant supply passage 221 is formed from the distribution zone forming shaft portion 222 to the small diameter shaft portion 223. The lubricant supply passage 221 communicates with a lubricant supply port 227. ing. Lubricant supply port 227
Is provided at a position substantially in the center of the thermal crosslinking zone 51 in the small-diameter shaft portion 223, and a lubricant is supplied to the small-diameter shaft portion 223 which is a resin contact surface through a lubricant supply port 227 by a pressure pump or the like. It is supplied to the outer peripheral surface.

The thermal crosslinking zone 51 provided with the lubricant supply port 227 and the lubricant supply port 211 is provided.
Is a position where the raw resin composition is developed so as to be in close contact with the small diameter shaft portion 223 and the small diameter cylindrical portion 213 over the entire periphery of the mold surface. The extruder 3 is configured to extrude and supply the raw material resin composition obtained by mixing the thermoplastic resin and the crosslinking agent to the mold 2 in a molten state.

Next, an embodiment of a method for continuously producing an oriented product in which a resin tube is continuously produced as an oriented product using the production apparatus 1 will be described in the order of steps. (1) The extruder 3 mixes and kneads a polyolefin-based resin containing a polyolefin compound as a thermoplastic resin as a main component and a thermal crosslinking agent, and melts the obtained kneaded material as a raw resin composition to form an extruder. 3 to the resin supply port 21
0 is supplied continuously.

At the same time, through the lubricant supply port 211 and the lubricant supply port 227, the inner peripheral surface of the mold body 21 and the outer peripheral surface of the mandrel 22, which are the resin contact surfaces, are at a temperature equal to or higher than the flow start temperature of the thermoplastic resin (flow start). (Temperature + 50 ° C.) or less, and a lubricant made of a thermoplastic resin having a melt viscosity in a range of 300 poise to 3000 poise at a shear rate of 10 / sec to 200 / sec is exuded.

(2) The raw resin composition supplied to the resin supply port 210 is sent to a clearance formed between the small diameter shaft portion 223 and the small diameter cylindrical portion 213 while adjusting the flow rate in the flow rate adjustment zone 50. Then, it is developed into a thick-walled cylinder and sent to the thermal crosslinking zone 51, where the thermoplastic resin in the raw resin composition is thermally crosslinked by a thermal crosslinking agent so as to have a degree of crosslinking of 5% or more and 70% or less. The small-diameter shaft portion 223 and the small-diameter cylindrical portion 2
13, the raw resin composition is placed on the wall surface in the mold, that is, the small-diameter shaft portion 22.
When the state is developed so as to be in close contact with the entire outer peripheral surface of the outer peripheral surface of the third cylindrical portion and the inner peripheral surface of the small-diameter cylindrical portion 213, the lubricant is supplied from the lubricant supply port 211 and the lubricant supply port 227. (3) The thermally cross-linked tubular cross-linked polyolefin resin is cooled and adjusted to a temperature at which it can be stretched in the cooling zone 52, fed to the stretching zone 53, and expanded by the taper of the expanded diameter shaft portion 226. Reduction to achieve uniaxial stretching or more.

(4) The tubular shaped article as a stretched body shaped into a gap between the large-diameter shaft portion 224 and the large-diameter cylindrical portion 214 by stretching in the stretching zone 52 is heated to a temperature lower than the orientation relaxation temperature, Cooling is performed while maintaining the shape to a temperature equal to or lower than the formation start temperature, and the oriented resin is cooled and solidified.

As described above, the resin tube thus obtained is stretched in a molten state, so that the resin deformation force can be greatly reduced. Since the polyolefin resin is crosslinked to form a stitch structure between the molecular chains, the molecular orientation can be ensured by stretching even during melting. In addition, since thermal crosslinking is performed so as to have a degree of crosslinking of 5% or more and 70% or less, slipping of molecular chains does not occur and the orientation is excellent.

Further, the supply of the lubricant is performed after the position where the raw resin composition is developed so as to be in close contact with the small diameter shaft portion 223 and the small diameter cylindrical portion 213 over the entire circumference of the mold surface. When the raw resin composition is completely contained in the clearance formed between the small-diameter shaft portion 223 and the small-diameter cylindrical portion 213, and then stretched, a molding state having uniform inner and outer diameters is obtained. And an oriented polyolefin tube having a good quality can be obtained.

[0039]

Embodiments of the present invention will be described below in more detail.

(Example 1) A mold 2 and an extruder 3 were prepared as shown in FIG. [Mold size]-Inner diameter of small-diameter tube portion 213: 60.0 mm-Inner diameter of large-diameter tube portion 214: 92.0 mm [Mandrel size]-Outer diameter of small-diameter shaft portion 223: 11.8 mm-Large-diameter shaft portion 224 Outer diameter: 86.0 mm [Extruder]-TEX30α manufactured by Japan Steel Works, L / D = 51, caliber 3
2mm

Then, high-density polyethylene (density 0.953, melt flow rate (MF
R) 0.03, weight average molecular weight 268,000, melting point 13
2 ° C., crystallization peak temperature 119 ° C.) into the extruder, and from the position of L / D = 35, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne- as a thermal crosslinking agent. 3 (Perhexin 25B manufactured by NOF Corporation,
(193 ° C., half-life time 60 seconds) was added to the extruder at a ratio of 0.1 part by weight to 100 parts by weight of the high-density polyethylene, and the high-density polyethylene and 2,5-dimethyl were added in the extruder at a resin temperature of 170 ° C. -2,5-di (t-butylperoxy) hexyne-3 was mixed and kneaded.

The obtained kneaded material was transferred to a gear pump (CORE).
X36 / 36, manufactured by Mag Corporation, 21 cc / rev), and then set from the resin supply port 210 of the mold body 21 to 220 ° C. in the thermal crosslinking zone 51, 140 ° C. in the cooling zone 52, and 160 ° C. in the stretching zone 53. Was continuously supplied into the mold 2 to obtain an oriented polyethylene tube having an outer diameter of 92.0 mm and an inner diameter of 86.0 mm.

Also, polyethylene glycol (average molecular weight 2000, viscosity 10.8 cSt (at
100 ° C)) to the lubricant supply port 2 with a plunger pump.
11 and the lubricant supply port 227 were supplied into the mold main body 21 so as to spread from the thermal crosslinking zone 51 between the raw resin composition and the resin contact surface in the mold.

In this embodiment, as shown in FIG. 2A, the passage time of the molding resin is 1 minute (the distance from the core connection portion (A in the figure) of the mandrel 22: 67.0 m).
m) (the outer diameter of the small-diameter shaft portion 223 is φ11.8 mm,
A lubricant supply port 227 and a lubricant supply port 211 were provided in the small-diameter cylindrical portion 213 having an inner diameter of 60.0 mm, respectively, to supply the lubricant.

In the extruder, the screw shaft is arranged from the upstream side to the downstream side in the first full flight shape part-first reverse full flight shape part-second full flight shape part-second reverse full flight shape part. The low pressure part (second full flight shape part) sandwiched between the high pressure part (first reverse full flight shape part) and the high pressure part (second reverse full flight shape part) using an extruder equipped with Supplied 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3.

(Comparative Example 1) As shown in FIG. 2B, the supply position of the lubricant to be supplied from the mandrel 22 side is changed to a portion which is an intermediate portion of the reduced diameter shaft portion 225 (a core connection portion in the mandrel 22). (A in the figure)) Lubricant supply port 227a
An attempt was made to obtain an oriented polyethylene pipe in the same manner as in Example 1 except that the supply was made from Example 1. However, an oriented polyethylene pipe having a predetermined size could not be obtained.

(Comparative Example 2) FIG.
As shown in (c), an oriented polyethylene pipe was obtained in the same manner as in Example 1, except that the lubricant was supplied from the lubricant supply ports 227b and 211b provided in the flow rate adjustment zone 50. However, it was not possible to obtain an oriented polyethylene pipe having a predetermined size.

The state of molding in the above Example 1 and Comparative Examples 1 and 2 was observed, and the dimensions of the inner and outer diameters, the state of molding, and the wall thickness accuracy of the obtained oriented polyethylene pipe were examined and are shown in Table 1. The measured dimensions of the oriented polyethylene tube are
With respect to the outer diameter, the wall thickness at four locations in the circumferential direction of the cross-sectional sample cut perpendicular to the extrusion direction was measured with a vernier caliper (1/100), and the average value was shown. The wall thickness was measured with a micrometer at a pitch of 5 mm in the circumferential direction of the obtained oriented polyethylene pipe, and the average value was shown.

Incidentally, the specification of the obtained oriented polyethylene pipe is such that the outer diameter is 92.0 ± 0.1 mm and the inner diameter is 86.
A good product having a thickness of 0 ± 0.1 mm and a thickness of 3.0 ± 0.1 mm was obtained.

[0050]

[Table 1]

From the results in Table 1, oriented polyethylene pipes could be obtained in all of Example 1, Comparative Example 1 and Comparative Example 2. However, as in Example 1, the lubricant supply port 227 and the lubricant supply port were obtained. Only when the lubricant is supplied from 211, it can be seen that an oriented polyethylene pipe whose wall thickness, inner diameter dimension and outer dimension fall within the standard could be obtained.

[0052]

As described above, the method for continuous production of an oriented product according to the present invention can easily perform high-density resin or high-magnification stretching during extrusion molding. In addition, it is possible to reliably and continuously obtain an oriented product having an intended stretching ratio.

In particular, when a cross-linking step for cross-linking the thermoplastic resin is provided as in the production method of the second aspect, an oriented product having more excellent strength can be obtained. Further, when a thermal cross-linking agent is contained in the raw resin composition as in the production method of the third aspect, and thermal cross-linking is performed, cross-linking can be performed efficiently.

Further, since the mold for continuous production of an oriented product according to the present invention is constituted as described above, it is necessary to perform high-density resin or high-magnification stretching when performing extrusion molding. Also, it is possible to continuously obtain oriented products with high accuracy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a manufacturing apparatus used for continuously manufacturing an oriented product of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a position of a lubricant supply port of a mold in the manufacturing apparatus of FIG. 1 is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Die 21 Die main body 211 Lubricant supply port 22 Mandrel 227 Lubricant supply port 3 Extruder 50 Flow rate adjustment zone 51 Thermal crosslinking zone 52 Cooling zone 53 Stretching zone

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court II (Reference) C08L 101: 00 C08L 101: 00 (72) Inventor Akihiro Ogawa 2-4-12 Nakazaki Nishi, Kita-ku, Osaka Sekisui Engineering Stock In-house F term (reference) 4F070 AA13 AA15 AA16 AA42 AA47 AA54 AA58 AB08 AC56 AE08 FB06 FC05 GA05 GB09 4F210 AA04 AB03 AG08 QA09 QC01 QC05 QG04 QG13 QG18

Claims (5)

[Claims] 1. A stretching process in which a raw resin composition containing a thermoplastic resin fed under pressure into a mold is shaped into a substantially molded product while being oriented in at least one axis orienting direction in a molten state. In the method for continuously producing an oriented product, comprising a step of supplying a lubricant to an interface between a raw resin composition supplied into the mold and a mold surface, the raw resin composition supplied into the die Characterized in that the lubricant is supplied from a state in which it is developed so as to be in close contact over the entire circumference of the wall surface in the mold and before the stretching step is reached, wherein a continuous method for producing an oriented product is provided. . 2. The continuous production method of an oriented product according to claim 1, further comprising a crosslinking step of crosslinking the thermoplastic resin before performing the stretching step. 3. A raw resin composition containing a thermal crosslinking agent,
3. The continuous production method for an oriented product according to claim 2, wherein thermal crosslinking is performed. 4. The continuous production method for an oriented product according to claim 1, wherein the thermoplastic resin is a crystalline thermoplastic resin. 5. A stretching process in which a raw resin composition containing a thermoplastic resin fed under pressure into a mold is shaped into a substantially molded product while being oriented in at least one axis orienting direction in a molten state. In a continuous production mold of an oriented product having a zone, a lubricant supply path for supplying a lubricant to an interface between a raw material resin composition supplied in the mold and a mold surface in the mold,
The outlet of the lubricant supply path is provided after the position where the raw resin composition supplied into the mold until reaching the stretching zone is developed so as to be in close contact with the entire circumference of the wall surface in the mold. A mold for continuous production of an oriented product.