JPH10230541A - Apparatus for producing resin molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molded object producing apparatus capable of dissolving sufficiently high non-reactive gas in a resin before the resin is melted and certainly performing the pressure seal of the non-reactive gas held in the high pressure state in the cylinder of an extruder. SOLUTION: An extruder 1b wherein a screw 12' is arranged in a cylinder 11' and a hopper 2 provided on the upstream side of the supply end part of the extruder 1b are provided an the hopper 2 has a pressure-resistant structure holding the pressure of the non-reactive gas to the predetermined position in the cylinder 11' of the extruder 1b in a high pressure state and the driven shaft 13' of the screw 12' connected to the motor 6 as a drive device through a speed reducer 5 is sealed by a viscous fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic resin, particularly a resin having a high melt viscosity, which is difficult to melt-extrude, a resin which is easily thermally decomposed, an additive having a low boiling point or an additive which is easily thermally decomposed. The present invention relates to an apparatus for manufacturing a resin molded body made of a resin or the like.

[0002]

2. Description of the Related Art Resins such as ultra-high molecular weight polyethylene, ultra-high polymerization degree polyvinyl chloride, and high chlorination degree polyvinyl chloride are resins that are extremely difficult to mold due to high melt viscosity and easy decomposition. It is generally called a difficult-to-mold resin.

Conventionally, in the case of such a difficult-to-mold resin having a very high melt viscosity, the following method has been employed for producing a molded article from the resin.

(1) A method in which a plate-like or rod-like molded body is directly produced without compression through a compression molding or a ram extrusion molding, and the molded body is shaped into a desired product by cutting out such as cutting. . (2) A method in which a difficult-to-mold resin is dissolved in an organic solvent and formed into a film or a sheet by a casting method. (3) A method in which a dispersion or a mixture obtained by adding an organic solvent to a powder of a difficult-to-mold resin as described in JP-B-4-47608 is heated and melted, extrusion-molded, and the organic solvent is volatilized after the molding.

However, the method (1) has a disadvantage that productivity is extremely low. In the above methods (2) and (3), if the solvent remains in the molded article, the physical properties of the molded article are deteriorated. Therefore, the molded article must be heated to evaporate the solvent. Requires a large-scale device for complete volatilization, and takes a long time,
Again, productivity is low. In addition, if the solvent is volatilized in the air as it is, there is a risk of causing pollution. Therefore, the solvent must be recovered, and there is a problem that the equipment cost of the recovery equipment and the like increases.

In the case of a difficult-to-mold resin whose decomposition temperature and molding temperature are close to each other, a method has been adopted in which a stabilizer or a plasticizer is added to the resin to minimize the decomposition of the resin. However, in this method, the physical properties of the resin decrease in proportion to the amount of the stabilizer or plasticizer added. Conversely, when the resin is molded without adding the stabilizer or plasticizer, the appearance of the molded article is deteriorated due to decomposition of the resin. Inevitably, the quality of the molded product is deteriorated due to the decrease in the molecular weight.

In order to solve the above problems, the inventors of the present invention first supply a difficult-to-form resin from an hopper to an extruder, transform the solid phase into a molten phase in the extruder, and convert the molten resin into the extruder. When the hopper is introduced into a mold and subjected to extrusion molding, the hopper has a pressure-resistant structure, and a high-pressure non-reactive gas, for example, carbon dioxide gas (carbon dioxide gas) is supplied into the hopper, and the carbon dioxide gas is converted into a hard-to-mold resin. (Japanese Patent Application No. 8-332154) has proposed a method for producing a difficult-to-mold resin molded article which transforms the resin while dissolving the resin.

[0008]

A problem with the apparatus in carrying out the above method is how to seal the high pressure non-reactive gas in the extruder. That is, if the pressure seal is not sufficiently performed,
When the pressure of the gas decreases due to the escape, the non-reactive gas once dissolved in the molten resin may volatilize from the resin or become bubbles inside the resin. In such a state, the amount of the non-reactive gas in the resin dissolved in the mold decreases,
The melt viscosity increases, making shaping difficult. In addition, there is a tendency that a non-foamed molded article to be described later cannot be obtained well, and even a foamed molded article tends to be a molded article in which bubbles vary. Therefore, when introducing the molten resin raw material melted by the extruder into the mold, it is necessary to sufficiently perform pressure sealing to maintain the resin pressurized state.

Therefore, for example, as a method for producing a thermoplastic resin foam sealed with the pressure of a high-pressure gas, a stirrer is provided between a hopper of an injection molding machine and a screw built-in cylinder having a pressure-resistant seal structure in a screw bearing portion. A method of installing a pressure-resistant chamber with a gas supply, supplying a pellet-shaped resin into the pressure-resistant chamber, dissolving high-pressure carbon dioxide gas in the resin in the pressure-resistant chamber, and then transferring the resin to a screw built-in cylinder in a high-temperature and high-pressure state. (Japanese Patent Laid-Open No. 8-851)
No. 28).

However, in this method, if the pressure-resistant seal structure of the screw bearing is made of, for example, metal, the bearing is slid, causing a problem of wear.

Further, Japanese Patent Application Laid-Open No. H8-11190 discloses that
In order to solve such a problem of pressure sealing of a high-pressure gas, a resin is completely melted in a first extruder using a tandem extruder, and a high-pressure inert gas is supplied to the molten resin. The high pressure inert gas is sealed by the first extruder, the first extruder and the second extruder and the second extruder.
A method is disclosed in which an inert gas is dissolved in a resin between an extruder and an adapter section.

However, in this method, if the back pressure of the resin is higher than the pressure of the supplied inert gas, the gas can be sealed, but the gas cannot be supplied until the resin is melted. There is a limit. Therefore, in the case of molding a difficult-to-mold resin, in order to mold a resin having a very high viscosity, it is necessary to melt a high-pressure gas in the resin before the resin is melted. We cannot respond to this request.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is capable of dissolving a sufficiently high-pressure non-reactive gas in a resin before the resin is melted, It is an object of the present invention to provide an apparatus for manufacturing a resin molded body capable of reliably performing pressure sealing of a non-reactive gas in a high pressure state.

[0014]

In order to achieve such an object, an apparatus for manufacturing a resin molded article according to the invention of claim 1 (hereinafter referred to as a "production apparatus of claim 1") is provided.
In an apparatus for manufacturing a resin molded body having an extruder in which a screw is disposed in a cylinder and a hopper provided above a supply end of the extruder, a non-reactive gas in a high-pressure state in which the hopper is introduced into the A pressure supply structure for holding the pressure, a gas supply device for supplying a high-pressure non-reactive gas to a predetermined position in the cylinder of the extruder is connected to the extruder, and the driving shaft of the screw connected to the driving device is a viscous fluid. The structure is sealed by

Further, an apparatus for producing a resin molded article according to the invention of claim 2 (hereinafter referred to as “production apparatus of claim 2”) comprises: an extruder having a screw disposed in a cylinder;
In a manufacturing apparatus for a resin molded article having a hopper provided on an upper side of a supply end of an extruder, the hopper has a pressure-resistant structure for holding a high-pressure non-reactive gas introduced thereto, and a cylinder of the extruder. A gas supply device that supplies a non-reactive gas in a high pressure state to a required position in the is connected to the extruder,
The drive shaft of the screw connected to the drive device was provided on the discharge side of the extruder.

In the manufacturing apparatus of the first aspect and the manufacturing apparatus of the second aspect, the manufacturing apparatus of the resin molded article according to the third aspect of the present invention (hereinafter referred to as "the manufacturing apparatus of the third aspect"). Preferably, a lubrication cooling mold is connected to the discharge end of the extruder. Further, as in the apparatus for manufacturing a resin molded product according to the invention of claim 4 (hereinafter referred to as “the manufacturing apparatus of claim 4”), a space between the discharge end of the extruder and the lubrication cooling mold is provided. It is also preferable to provide a resin pressure adjusting device. As the resin pressure adjusting device, a gear pump is preferable, as in the device for manufacturing a resin molded product according to the invention of claim 5 (hereinafter referred to as “the manufacturing device of claim 5”).

A typical example of the target resin to which the apparatus for manufacturing a resin molded article according to the present invention can be applied is a difficult-to-mold resin, but the target resin is not limited to the difficult-to-mold resin, and for example, a thermoplastic resin may be used. It can be applied to the production of fine cell foams by dissolving inorganic gas at a high concentration. Examples of the difficult-to-mold resin include a resin having a high melt viscosity and being difficult to be melt-extruded, a resin easily decomposed by heat, a resin containing a low boiling point additive or an additive easily decomposed by heat, and the like.

Examples of the resin which has a high melt viscosity and is difficult to melt-extrude include resins such as ultrahigh molecular weight polyethylene, ultrahigh polymerization degree polyvinyl chloride, polytetrafluoroethylene and polyimide. Examples of resins that are easily decomposed thermally include biodegradable resins such as polylactic acid and polyhydroxybutyrate, polyvinyl chloride having a high degree of chlorination, and polyacrylonitrile.

The non-reactive gas used in the present invention is an organic or inorganic substance which is a gas at normal temperature and normal pressure and which does not react with the difficult-to-mold resin and does not deteriorate the resin. Can be used without particular limitation. For example, carbon dioxide, nitrogen, argon, neon, helium,
Examples include inorganic gases such as oxygen, and organic gases such as chlorofluorocarbon and low molecular weight hydrocarbons. These may be used alone or in combination of two or more. Of these, inorganic gas, particularly carbon dioxide gas, is most preferable because it does not require gas recovery, has high solubility in the resin, and significantly lowers the melt viscosity of the resin.

The amount of the non-reactive gas dissolved is not particularly limited as long as the melt viscosity of the resin becomes a viscosity suitable for molding by dissolution, and is appropriately determined depending on the type of the resin, the type of the non-reactive gas, and the like. Can be

The apparatus for producing a resin molded article according to the present invention can be used for producing any of a foamed molded article and a non-foamed molded article. When obtaining a foam molded article, a mold having a conventional structure for extrusion foaming may be used at the time of extrusion molding, and a mold shape, a resin flow viscosity, or a mold which affects the degree of pressure drop at a mold outlet. By appropriately setting the molding conditions such as the temperature and the extrusion amount, it is possible to control the form and the diameter of the bubbles.

On the other hand, when a non-foamed molded article is obtained, the following method can be adopted.

(I) A method in which the resin is sufficiently cooled in a mold and extruded in a solidified state. In this method, it is also possible to take measures such as using a liquid lubricant to reduce the flow resistance of the resin in the mold, or applying vibration to the mold to reduce the frictional resistance between the wall surface and the resin surface. preferable. (ii) A method of performing rapid sizing while maintaining the pressure from the mold outlet.

(Iii) A method of removing air bubbles from a molded body by applying pressure in a temperature range of plastic deformation when forming the foamed body from a mold outlet.

As the method using the liquid lubricant in the above method (i), a conventionally known method can be arbitrarily applied.
As the liquid lubricant used in this method, decomposition, boiling, etc. are difficult to occur at the molding temperature, and do not melt in the resin,
A chemically stable substance that does not promote the deterioration of the resin is preferable. Examples of the lubricant satisfying such conditions include liquid polysiloxane, polyhydric alcohol such as ethylene glycol, and its alkyl ester and alkyl ether, polyoxyalkylene and its alkyl ester, and alkyl ether, polyoxyalkylene and Examples thereof include random, block or graft copolymers of two or more alkylene oxides. Above all, water-soluble lubricants such as the above-mentioned polyhydric alcohols are preferable in that they are easily removed after adhering to the surface of the molded article.

In order to uniformly cover the surface of the resin with the lubricant, the inner wall of the mold is made of a porous material, and the inside of the mold is exposed from the outside of the inner wall of the mold so that the lubricant may seep into the inner surface of the mold. It is desirable to supply a lubricant to the inner wall. As the material of the porous body, for example, aluminum, stainless steel, titanium, gold, silver, a metal-based material mainly composed of copper and the like, alumina,
There are nonmetallic materials mainly composed of 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, the pore diameter, the porosity of the porous body constituting the inner wall of the mold, and the thickness of the inner wall of the mold.

In order to uniformly apply the lubricant to the resin interface, it is preferable to select a porous body having a sharp pore distribution curve and uniformly dispersed pores as the porous body constituting the mold wall surface. . As a porous body satisfying such conditions, it is desirable to use a non-ferrous metal-based material.

As means for applying vibration to the mold,
Conventionally known ones can be applied. For example, the mold is vibrated by using a vibration motor, a vibrator, an ultrasonic wave or the like.
In this case, the frequency of the vibration is not particularly limited, but is preferably 100 to 100000 Hz, more preferably 50 to 100 Hz.
0 to 3000 Hz. On the other hand, the vibration amplitude is preferably 0.5 to 1000 μm, more preferably 1 to 500 μm.
m.

In the above method (iii), when the difficult-to-mold resin is a crystalline resin, the plastic deformation temperature range is preferably in the range of (melting point−20 ° C.) to (melting point + 100 ° C.), more preferably (Melting point) to (Melting point + 50 ° C).

On the other hand, when the difficult-to-mold resin is an amorphous resin, the plastic deformation temperature range is preferably in the range of (glass transition temperature -10 ° C.) to (glass transition temperature + 150 ° C.), and more preferably (glass transition temperature + 150 ° C.). (Glass transition temperature) to (glass transition temperature + 80 ° C.).

The pressure applied to the compact during shaping is preferably ^{2 to} 300 kgf / cm ² , more preferably 5 to 250 kgf / cm ² .
kgf / cm ^2, particularly preferably 10~200kgf / cm ^2.

The time required for shaping under pressure (hereinafter referred to as "shaping time") is preferably at least 1 second, more preferably at least 5 seconds. If the shaping time is less than 1 second, foaming remains in the resin, a molded article having a uniform shape cannot be obtained, and desired physical properties may not be sufficiently exhibited. Further, although there is no upper limit of the shaping time, if this time is too long, the productivity is lowered, which is not preferable.

The method of applying pressure to the molded body is not particularly limited as long as the above-mentioned predetermined pressure and molding time can be satisfied. For example, the molded body is shaped by a surface pressure like a double belt press. , A method of shaping between a belt and a roll, a method of shaping between a roll and a roll, and the like.

Further, by forming an uneven pattern such as an embossed pattern on the surface of the roll or the belt at the time of shaping, the uneven pattern is transferred to the surface of the formed article to obtain a difficult-to-mold resin molded article having excellent decorativeness. Can be. The cooling temperature after shaping is lower than the heat deformation temperature of the resin. If the cooling temperature is equal to or higher than the heat deformation temperature, the molded body may be deformed in a process such as winding.

The above-mentioned shaping process is a method of obtaining a molded body by extrusion. However, the manufacturing apparatus according to the present invention is not limited to the extrusion molding. By changing the shaping process, for example, injection molding or pressing can be performed. Applicable to molding.

[0036] In the manufacturing apparatus according to claim 1, the viscous fluid, a fluid having a viscosity of 1 ～1000000Poise, and specific examples thereof include high viscosity oil or a molten resin. When a molten resin is used, a resin that does not deteriorate due to heat is preferable. As a method of supplying a viscous fluid around the drive shaft,
Although not particularly limited, for example, there is a method in which a viscous fluid having excellent lubricity is extruded from another extruder, and the viscous fluid is continuously supplied around the drive shaft.

The pressure of the viscous fluid is not particularly limited as long as the high-pressure gas in the cylinder of the extruder can be sealed, but is preferably 5 kg / cm ² to supply gas pressure, and more preferably 10 kg / cm ² to supply. Gas pressure. That is, if the pressure of the viscous fluid is less than 5 kg / cm ² , the viscous fluid cannot sufficiently serve as a lubricant for the drive shaft due to the gas pressure in the cylinder. Fluid may mix into the molten resin in the cylinder.

The feed rate of the viscous fluid is preferably 0.1 to
The pressure is 5 kg / hr, more preferably 1-3 kg / hr, and the pressure of the viscous fluid can be adjusted by a gear pump or the like.

[0039]

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 schematically shows an example of the manufacturing apparatus according to the second aspect.

As shown in FIG. 1, this manufacturing apparatus (A)
Extruder (1a) with screw (12) arranged in cylinder (11)
And a hopper (2) provided above the supply end of the extruder (1a) via an open / close valve (21), and a lubricating cooling mold (3) connected to the discharge end of the extruder (1a). ).

The hopper (2) has a pressure-resistant structure so that a high-pressure non-reactive gas can be injected into the hopper (2), and is connected to a non-reactive gas cylinder (22).
Open / close valve (23) and pressurizing pump in the gas supply line
(24) is provided. That is, the open / close valve (23) is opened and the pressurized pump (24) is inserted into the hopper (2) from the gas cylinder (22).
A non-reactive gas brought to a high pressure state is supplied, and the supplied non-reactive gas is
Resin raw materials such as resin pellets filled in the hopper (2)
(9) to be dissolved.

On the other hand, the extruder (1a) is provided with a gas supply device (4) having the following structure for supplying a high-pressure non-reactive gas into the cylinder (11). That is, the gas supply device (4) is a fore gas supply hole (41a) for supplying gas to the solid transporting part provided on the slightly upstream part of the hopper connection part of the extruder (1a), A downstream gas supply hole (4) for supplying gas to the melt transport section provided at the upper center in the longitudinal direction of the extruder (1a).
1b).

The upstream and downstream gas supply holes (41a)
(41b) are connected to gas cylinders via gas supply lines.
(42) and open / close valves (43a) and (43b) and pressurizing pumps (44a) and (44
b) is provided.

That is, when the gas supply device (4) operates the pressurizing pump (44a) and opens the valve (43a), the non-reactive gas in the gas cylinder (42) is brought into a high pressure state and the upstream gas supply hole is opened. (41a) to the solids transport section of cylinder (11)
Activate the pressure pump (44b) and open the valve (43b).
The non-reactive gas in the gas cylinder (42) can be supplied to the melt transport section of the cylinder (11) from the downstream gas supply hole (41b) in a high pressure state. Of course, the upstream and downstream gas supply holes
(41a) and (41b) can be supplied simultaneously from both sides.

The screw (12) has its drive shaft (13) protruding to the outside through a downstream end wall on the discharge end side of the cylinder (11), and this protruding end is passed through a speed reducer (5). A motor (6) as a driving device is connected to the resin material (9) supplied from the hopper (2) into the cylinder (11) while being mixed and melted and sent to the discharge end side. ing.

The lubricating cooling mold (3) is connected to the extruder (1a) through a discharge pipe (7) provided at the discharge end of the extruder (1a), and the inner wall (32) of the mold is cooled. The lubricant can be supplied to the mold inner surface (33) through the porous body from a lubricant reservoir (31) provided on the upper surface of the porous body forming the mold inner wall (32), which is formed of a porous body. It has become. That is, the molten resin raw material (91) maintained in the pressurized state sent from the extruder (1a)
The lubricant is supplied from the lubricant reservoir (31) to the mold inner surface (33) to form a desired shape while cooling the frictional resistance between the mold inner surface (33) and the molten resin raw material (91), and then cooled. And push it out.

Further, a gear pump (71) as a resin pressure adjusting device is provided in the middle of the discharge pipe (7), and the molten resin raw material (91) is lubricated and cooled at a predetermined pressure. Can be supplied.

Further, the extruder (1a) and the lubricating cooling mold (3)
Both have a temperature control device (not shown),
It can be controlled to a predetermined temperature.

As described above, the manufacturing apparatus (A) is provided on the discharge end side of the cylinder (11) in which the drive shaft (13) of the screw (12) is filled with the molten resin. Because
By making the gas pressure of the non-reactive gas supplied into the cylinder (11) smaller than the back pressure of the molten resin raw material (91) melted in the cylinder (11), the cylinder (11) and the drive shaft (13 ) Can reliably prevent non-reactive gas from leaking from the molten resin raw material (91). That is, the cylinder (11)
The interior can be maintained at a high pressure, and the non-reactive gas once dissolved can volatilize from the molten resin raw material (91), or the cylinder (11)
Does not bubble inside. Therefore, a uniform non-foamed molded article can be stably obtained.

In addition to the hopper (2),
Hopper (2), solid transport section of cylinder (11), cylinder (11)
It is possible to arbitrarily supply a high-pressure non-reactive gas as required at three places in the melt transport section of (a), ie, (a) opening the on-off valve (23) and opening the hopper
When the non-reactive gas is supplied into (2), the non-reactive gas can be dissolved in the resin in the hopper (2), and (b) the on-off valve (43a) is opened to open the upstream gas supply hole (41a). ) To supply the non-reactive gas to the solid transport section of the cylinder (11), the non-reactive gas can be dissolved in the resin in the solid transport section of the cylinder (11) and in the subsequent flow. (43
b) is opened and the non-reactive gas is supplied from the downstream gas supply hole (41b) to the melt transport section of the cylinder (11), and the non-reactive gas is supplied to the melt transport section of the cylinder (11) and the downstream stream. In addition to being able to supply and dissolve a high-pressure non-reactive gas to the resin before the resin is transformed from the solid phase to the molten phase, A non-reactive gas in a high-pressure state can be supplied to the melted resin to dissolve it.

That is, by dissolving the non-reactive gas in the resin under high pressure, the non-reactive gas diffuses between the resins to increase the free volume between the polymer chains. Since the resin is plasticized, the melt viscosity and the glass transition temperature can be reduced. Even if the resin has a high viscosity, melt extrusion cannot be performed, and the molding temperature can be lowered for a resin which is easily thermally decomposed.

Therefore, it is possible to control the amount of the non-reactive gas dissolved in the best condition in accordance with the resin to be molded, guide it to a mold corresponding to the shape of the desired product, and shape the product.

In this manufacturing apparatus (A), a lubricating cooling mold (3) is used as a mold, so that a desired molded product can be obtained smoothly. Moreover, a gear pump (71) is provided in the middle of the discharge pipe (7) to supply the molten resin material (91) from the extruder (1a) to the mold (3). ) Can be always quantitatively introduced into the mold (3), and a good molded product can be obtained.

The method of supplying a high-pressure non-reactive gas to both the solid transporting section and the melt transporting section and dissolving it in the resin is effective means for increasing the throughput in order to improve productivity. Become.

In any of the methods, the supply of the high-pressure non-reactive gas to the resin raw material must be performed before the resin is transformed from a solid phase to a molten phase. If this is not done, if the melt viscosity of the difficult-to-mold resin is extremely high, for example, when the resin is plasticized with a screw, etc., the screw will not rotate due to a sudden increase in torque, etc. This is because a problem may occur, and in the case of a resin that is very sensitive to heat, thermal decomposition may proceed before the non-reactive gas is dissolved in a molten state.

Further, when the target hard-to-mold resin is a crystalline resin, a high-pressure gas is supplied from the upstream gas supply hole (41a) before the resin is transformed from a solid phase to a molten phase. In addition to dissolving in the resin, the downstream gas supply hole (41b)
It is preferable to supply a non-reactive gas in a high pressure state to the melt transporting unit from above, and dissolve it in the resin. This is because, in the case of crystalline resin, the gas dissolves only in the amorphous portion in the solid phase state of the resin, so the dissolved amount is small and its effect is small, and it is difficult to reach the melt transport section where the crystal structure is collapsed. The required amount of melting can be compensated by supplying the non-reactive gas in a high pressure state.

FIG. 2 schematically shows an example of the manufacturing apparatus according to the first aspect. As shown in FIG.
(B) shows that the drive shaft (13 ') of the screw (12') is a cylinder.
(11 ') having an extruder (1b) provided so as to penetrate the resin supply side wall, and a viscous fluid supply device (8) so that high-pressure gas does not leak from a through hole of the drive shaft (13'). ), And is the same as the above-described manufacturing apparatus (A) except that a discharge pipe (7 ′) is connected to the downstream end wall.

That is, the viscous fluid supply device (8) includes an extruder (81) and a circulation path (82), and extrudes a molten resin (not shown) as a viscous fluid from the extruder (81). Circuit (8
A gear pump (8) provided in the middle of the circulation path (82) through (2)
3) A seal portion provided so as to quantitatively surround the drive shaft (13 ') at a pressure in the range of 5 kgf / cm ² to the supply gas pressure according to 3).
(84), and again through the circulation path (82).
While returning to 1), air bubbles in the molten resin returned by the vacuum pump (85) connected to the vent port of the extruder (81) can be degassed.

As described above, in the manufacturing apparatus (B), the drive shaft (13 ') is sealed by the seal portion (84) with the viscous fluid. High pressure state non-reactive gas does not leak out of the cylinder (11 ') from the drive shaft (13'),
1)) can be maintained in a high pressure state.

Further, since the gas pressure in the cylinder (11 ') is higher than the pressure of the viscous fluid used for the seal, the viscous fluid used for the gas seal may be mixed into the resin raw material in the cylinder (11'). There is no.

The high-pressure gas can be sealed with the viscous fluid lower than the gas pressure on the high-pressure gas side only when the resin is sent to the upstream by the screw (12 ') of the extruder (1b). In other cases, if the viscous fluid used for the gas seal is circulating, the gas does not blow out at once. In addition, the pressure of the viscous fluid is
Since the pressure is lower than the gas pressure in 1 ′), the non-reactive gas in the cylinder (11 ′) dissolves in the viscous fluid. This dissolved gas is supplied to the vacuum pump connected to the vent of the extruder (81).
Since the gas is deaerated by (85), the sealing property of the viscous fluid can be more reliably ensured.

The manufacturing apparatus according to the present invention is not limited to the above embodiment. For example, in the manufacturing apparatuses (A) and (B) of the above embodiment, the non-reactive gas in the gas cylinders (22) and (42) are all pumped by the pressure pumps (24), (44a) and (44b). Although they are supplied under pressure, they may be supplied directly from a gas cylinder. Also manufacturing equipment
In (B), the drive shaft (13 ') of the screw (12') is provided so as to penetrate the resin supply side wall of the cylinder (11 '). 11 ') may be made to protrude to the outside through the downstream end wall on the discharge end side.

[0063]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) A molded product was produced as follows using a production apparatus as shown in FIG. First, as a difficult-to-mold resin, ultra-high-molecular-weight polyethylene of ultra-high-viscosity material ("HIZEX Million 24" manufactured by Mitsui Petrochemical Industries, Ltd.
0M "average molecular weight 2.3 million, melting point 136 ° C) was fed into the cylinder of the extruder from a hopper of a single screw extruder (screw diameter 40 mm, L / D = 30). Carbon dioxide gas is used as the gas, and the carbon dioxide gas is supplied to the solid transport section of the single screw extruder.
It was press-fitted with a pressure of 0 kgf / cm ² .

The resin is melted in the cylinder of the single-screw extruder set at 200 ° C. in this way, and carbon dioxide gas is further supplied from the melt transport section of the single-screw extruder at a pressure of 200 kgf / cm ^2. When the mixture was sufficiently melt-kneaded in a single-screw extruder under the condition of 5 kg / hr, no gas leakage from the drive shaft was observed. At this time, the back pressure of the extruder was 350 kgf /
It was cm ^2.

Subsequently, the molten resin raw material is supplied to a lubricating cooling mold set at 100 ° C. through a gear pump connected to a discharge pipe of a single screw extruder, molded, quenched and solidified. A 10 mm diameter solid compact was extruded.

Microscopic observation of the cross section of this solid molded product confirmed that no air bubbles were observed, and that the solid molded product was a non-foamed solid molded product having a uniform surface. In this lubrication cooling mold, polyethylene glycol as a lubricant stored in the lubricant reservoir is supplied to the inner surface of the mold at a rate of 5 cc / min. The lubricant was applied uniformly over the entire circumference.

(Example 2) Using a manufacturing apparatus as shown in FIG. 2, a molded body was manufactured as follows. First, as a difficult-to-mold resin, a heat-sensitive polylactic acid (“RESOMEL L209” manufactured by Boehringer Ingelheim Co., Ltd., weight average molecular weight: 500,000) was extruded into a single screw extruder (screw diameter: 40 mm).
mm, L / D = 30) and fed into the cylinder of the single screw extruder. Carbon dioxide gas was used as the gas, and the carbon dioxide gas was injected into the solid transport section of the single screw extruder at a pressure of 100 kgf / cm ² . Then, the extruding amount is 2kg in the cylinder of the extruder.
/ Hr at a barrel setting temperature of 170 ° C.

Subsequently, it is supplied to a lubricating cooling mold set at 80 ° C. through a gear pump connected to a discharge pipe of the single screw extruder, and is molded, rapidly cooled and solidified, and has a rod-shaped diameter. A 10 mm solid compact was extruded.

The viscous fluid supply device is a high-density polyethylene ("HIZEX 8000" manufactured by Mitsui Petrochemical Industries, Ltd.) as a viscous fluid by using an extruder of the viscous fluid supply device.
F) (melt flow rate = 0.03, melting point 130 ° C.) was extruded at 145 ° C. and fed to the seal of the drive shaft of the single screw extruder using a gear pump. The supplied resin was then returned to the extruder, and the gas content in the resin was degassed by a vacuum pump at the vent of the extruder, and was again supplied to the drive shaft and circulated.

Gas leakage from the drive shaft of the screw of the extruder was not recognized, and the back pressure of the single-screw extruder at this time was 2
It was 50 kgf / cm ² . In the lubricating cooling mold, polyethylene glycol as a lubricant stored in the lubricant reservoir is supplied to the inner surface of the mold at a rate of 5 cc / min through the inner wall of the mold formed by the porous body, and is applied to the entire periphery of the interface with the molten resin. The lubricant was applied uniformly over the entire area.

Microscopic observation of the cross section of the solid molded body obtained as described above confirmed that no air bubbles were observed and the solid molded body had a smooth and uniform surface and was non-foamed.
In addition, when the molecular weight was measured by GPC (gel permeation chromatography), it was found that the molecular weight did not decrease before and after the extrusion, and no decomposition or the like occurred.

[0073]

According to the apparatus for manufacturing a resin molded article of the present invention, a sufficiently high-pressure non-reactive gas can be dissolved in a resin before the resin is melted, and the resin can be effectively plasticized. In addition, it is possible to mold a resin having a high melt viscosity, which is difficult to be melt-extruded, or a resin which is easily decomposed at a low temperature without any trouble.

Further, since the high-pressure gas in the cylinder does not escape from the drive shaft portion to the outside, the pressure seal of the gas in the high-pressure state can be performed more reliably.

Further, since the non-reactive gas can be supplied not only to the hopper portion but also to the cylinder portion of the extruder, the non-reactive gas can be more reliably dissolved in the resin, and the extrusion amount can be increased. Thus, productivity can be further improved. Further, according to the manufacturing apparatus of the second aspect, sealing of the high-pressure non-reactive gas in the cylinder of the extruder can be performed more easily.

Further, when a lubrication cooling mold is used as the mold as in the manufacturing apparatus of the third aspect, a desired molded product can be obtained smoothly.

Further, as in the manufacturing apparatus of the fourth aspect, a gear pump is provided in the middle of the discharge line of the extruder, particularly, as the manufacturing apparatus of the fifth aspect as the resin pressure adjusting means. If this is the case, the molten resin raw material can always be introduced into the mold in a constant amount, and a better molded product can be obtained. In addition, since the non-reactive gas dissolved in the obtained molded body escapes naturally from the molded body, a solvent recovery step such as a conventional method of plasticizing a resin with an organic solvent is not required, and productivity is improved. In addition, the size of the equipment can be reduced and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a manufacturing apparatus according to claim 2;
It is a vertical longitudinal view showing the outline.

FIG. 2 shows an embodiment of the manufacturing apparatus according to claim 1;
It is a vertical longitudinal view showing the outline.

[Explanation of symbols]

 (A), (B): Manufacturing equipment (1a), (1b): Extruder (2): Hopper (3): Lubrication cooling mold (4): Gas supply device (5) ・ ・ ・ Reduction gear (6) ・ ・ ・ Motor (drive device) (7), (7 ′) ・ ・ ・ Discharge pipeline (8) ・ ・ ・ Viscous fluid supply device (9) ・ ・ ・ Resin Raw materials (11), (11 ') ... cylinders (12), (12') ... screws (13), (13 ') ... drive shafts (21), (23), (43a), (43b) ・ ・ ・ Open / close valve (22), (42) ・ ・ ・ Gas cylinder (24), (44a), (44b) ・ ・ ・ Pressure pump (31) ・ ・ ・ Lubricant reservoir (32) ・ ・・ Inner wall of mold (33) ・ ・ ・ Inner surface of mold (41a) ・ ・ ・ Gas supply hole for upstream (41b) ・ ・ ・ Gas supply hole for downstream (71) ・ ・ ・ Gear pump (resin pressure adjusting device) (81 ) ・ ・ ・ Extruder (82) ・ ・ ・ Circulation path (83) ・ ・ ・ Gear pump (84) ・ ・ ・ Seal part (85) ・ ・ ・ Vacuum pump (91) ・ ・ ・ Molten resin material

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B29C 47/92 B29C 47/92 (72) Inventor Eiji Matsumoto 2-2 Kamikoba Kaminokocho Minami-ku, Kyoto Sekisui Kagaku Corporation

Claims (5)

[Claims] 1. A high-pressure state in which a hopper is introduced into an apparatus for producing a resin molded body, comprising: an extruder having a screw disposed in a cylinder; and a hopper provided above a supply end of the extruder. A pressure supply structure for holding the non-reactive gas under pressure, a gas supply device for supplying a high-pressure non-reactive gas at a predetermined position in a cylinder of the extruder is connected to the extruder, and a screw connected to a driving device is provided. An apparatus for manufacturing a resin molded product, wherein a drive shaft is sealed with a viscous fluid. 2. A high-pressure state in which a hopper is introduced into an apparatus for manufacturing a resin molded body, comprising: an extruder having a screw disposed in a cylinder; and a hopper provided above a supply end of the extruder. A pressure supply structure for holding the pressure of the non-reactive gas is connected to the extruder. An apparatus for manufacturing a resin molded product, wherein a drive shaft is provided on a discharge section side of an extruder. 3. The apparatus for manufacturing a resin molded product according to claim 1, wherein a lubricating cooling mold is connected to a discharge end of the extruder. 4. The apparatus for manufacturing a resin molded product according to claim 3, wherein a resin pressure adjusting device is provided between the discharge end of the extruder and the lubricating cooling mold. 5. The apparatus according to claim 4, wherein the resin pressure adjusting device is a gear pump.