JP2005161596A - Manufacturing method of thermoplastic resin blend - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent bubbles from remaining in a thermoplastic resin blend in a manufacturing method of the thermoplastic resin blend using an extruder characterized in that carbon dioxide is added to at least two kinds of thermoplastic resins in a molten state. <P>SOLUTION: This manufacturing method of the thermoplastic resin blend is constituted so that at least two kinds of the thermoplastic resins are supplied to a first extruder to be melted and carbon dioxide is added to and mixed with the molten thermoplastic resins in an amount of 2-200 pts.wt. with respect to 100 pts.wt. of the sum total amount of the thermoplastic resins while the prepared mixture is supplied to a second extruder from the leading end of the first extruder through a connection pipe to degass carbon dioxide from at least one upstream degassing port and at least one downstream degassing port provided to the cylinder of the second extruder through the supply port of the connection pipe before extruding the thermoplastic resins. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a thermoplastic resin blend by mixing two or more thermoplastic resins in a molten state in the presence of carbon dioxide.

  In recent years, the performance required for thermoplastic resin materials has become sophisticated and diversified, and it has become difficult to satisfy these needs with a single thermoplastic resin material. Therefore, research and development have been actively conducted in order to meet various needs as a multi-component thermoplastic resin material by combining several types of thermoplastic resins having different properties. These techniques are called polymer blends, polymer alloys, polymer composites and the like. Among them, a method for producing a thermoplastic resin blend by melt-blending two or more kinds of thermoplastic resins in an extruder is a well-known technique and is practiced industrially. This method has a great merit that it can be carried out relatively easily, can be continuously produced, and is low in cost.

However, the method has the following problems.
(A) When the melting temperature and the melt viscosity between different thermoplastic resins are significantly different, they cannot be uniformly dissolved and dispersed.
(B) When the compatibility between different types of thermoplastic resins is poor, a compatibilizing agent such as a block copolymer or a graft copolymer is generally added to reduce the interfacial tension. However, it is difficult to design and select a compatibilizing agent, and there are many examples of performance deterioration due to the addition of the compatibilizing agent.
(C) When melt blending at a high temperature is required, there is a possibility of performance deterioration due to decomposition or the like, and there are many examples that lead to performance deterioration due to the influence of plasticizer addition.

  From the above, it is known that the melt blending technique using an extruder can be easily carried out, but is greatly restricted by the thermoplastic resin material used, molding conditions, and the like.

  In producing a thermoplastic resin blend by mixing two or more kinds of thermoplastic resins in a molten state, the inventors of the present invention have 2 to 2 carbon dioxide with respect to 100 parts by weight of the total amount of the thermoplastic resins. A method for producing a thermoplastic resin blend characterized in that it is added at a ratio of 200 parts by weight (see Patent Document 1). By this method, when different types of thermoplastic resins are melted and mixed, by using carbon dioxide as a medium, a good fine dispersion structure can be obtained without using compatibilizers and plasticizers that adversely affect physical properties. A thermoplastic resin blend having a finely dispersed structure made of a heterogeneous incompatible thermoplastic resin, which has been impossible to achieve by conventional melt mixing methods, can be easily and efficiently produced at low cost. Can be manufactured.

  However, even in this method, small bubbles may remain in the molded product after molding depending on the extrusion conditions, materials used, and the ratio thereof. This is because carbon dioxide cannot be completely degassed in the degassing step. It was thought that there was.

  As a technique for devolatilization from an extruder, a method using a twin screw extruder having a rear vent and a plurality of vent ports is disclosed as a method for recovering polystyrene from a solution of expanded polystyrene in limonene or methylene chloride solvent. (See Patent Document 2), however, there is no description of a technique for degassing carbon dioxide from a thermoplastic resin.

JP 2002-322288 A JP 2001-146531 A

  An object of the present invention is a method for producing a thermoplastic resin blend using an extruder, characterized in that carbon dioxide is added to a thermoplastic resin in a molten state composed of two or more kinds. It is to provide a production method in which bubbles do not remain.

  As a result of intensive studies to solve the above problems, the present inventors have provided a degassing port for removing carbon dioxide at a specific position of the extruder, so that bubbles remain in the molded body of the thermoplastic resin blend. As a result, the present invention was completed.

That is, the present invention is specified by the following items.
(1) Two or more types of thermoplastic resins are supplied to the first extruder and melted, and the molten thermoplastic resin is 2 to 200 parts by weight of carbon dioxide with respect to 100 parts by weight of the total amount. And the mixture is fed from the tip of the first extruder through the connecting pipe to the second extruder, and in the second extruder, from the connecting pipe supply port provided in the cylinder. A method for producing a thermoplastic resin blend comprising degassing carbon dioxide from one or more upstream degassing ports and one or more downstream degassing ports to extrude a thermoplastic resin.

(2) In the first extruder, 0.01 to 50 parts by weight of a low molecular organic compound is further added to the molten thermoplastic resin with respect to the total amount of 100 parts by weight. The method for producing a thermoplastic resin blend according to (1), wherein degassing is performed together with carbon dioxide from a degassing port provided in a cylinder of the machine.

(3) In the above (2), the low molecular organic compound is one or more compounds selected from the group consisting of alcohols having 1 to 5 carbon atoms, alkanes, carboxylic acids, ethers, acetone, and benzene. The manufacturing method of the thermoplastic resin blend of description.

(4) The method for producing a thermoplastic resin blend according to any one of (1) to (3), wherein the resin pressure from the carbon dioxide addition part of the first extruder to the downstream end is 12 to 50 MPa.

(5) The method for producing a thermoplastic resin blend according to any one of (1) to (4), wherein the first extruder is a single-screw extruder.

  According to the present invention, two or more different types of thermoplastic resins can be easily and efficiently produced at low cost without using a compatibilizing agent or a plasticizer.

  The present invention will be described with reference to FIG. 1 showing an embodiment of the present invention in a system diagram.

  In order to manufacture the thermoplastic resin blend 7, first, for example, the thermoplastic resin 10 a serving as the sea phase and the thermoplastic resin 10 b serving as the island phase are uniformly mixed by the mixer 11 to obtain a thermoplastic resin mixture. At this time, two or more thermoplastic resins may be used.

  After the thermoplastic resin mixture prepared as described above is supplied from the hopper 12 to the first extruder 1 and heated and melted, carbon dioxide is used as a medium in an amount of 2 to 200 parts by weight, preferably 100 parts by weight of the thermoplastic resin. 3 to 150 parts by weight, more preferably 5 to 100 parts by weight, still more preferably 5 to 70 parts by weight, still more preferably 5 to 50 parts by weight, still more preferably 5 to 30 parts by weight, and even more preferably 7 to 30 parts by weight, particularly preferably 7 to 20 parts by weight is added.

  By adding carbon dioxide in the above ratio and dissolving it in the molten thermoplastic resin composition, the difference in melt viscosity between different types of thermoplastic resins and the difference in interfacial tension can be reduced, and the uniform dispersibility can be greatly improved. . In addition, melt blending at a low temperature is possible, and there is an effect of reducing the possibility of product performance deterioration due to decomposition or the like.

  In addition, since there is no need to add a compatibilizing agent or a plasticizer, there is no fear of deterioration of physical properties of the product. Further, removing the added carbon dioxide has an effect of extracting impurities at the same time. Due to the above synergistic effect, it is possible to achieve uniform fine dispersion polymer blends using incompatible different types of thermoplastic resins, which had been impossible with conventional melt blending, and at low cost, high quality and high performance thermoplastic resin with few impurities. It becomes possible to obtain a blend.

  Carbon dioxide is preferably added to the molten thermoplastic resin in the extruder at a pressure of 12 to 50 MPa, more preferably 15 to 30 MPa. By using carbon dioxide at this pressure, a predetermined amount of carbon dioxide can be stably supplied.

  In the first extruder 1, two or more kinds of thermoplastic resins are melted and mixed in the presence of carbon dioxide to produce a molten thermoplastic resin in a mixed state. The resin pressure from the carbon dioxide addition part 8 in the first extruder 1 to the first extruder downstream end 9 is preferably 12 to 50 MPa, more preferably 15 to 30 MPa. The pressure values in the present invention are all gauge pressures.

  By applying the resin pressure within the above range, a predetermined amount of carbon dioxide can be completely dissolved in the molten thermoplastic resin, and the difference in melt viscosity between different types of thermoplastic resins and the difference in interfacial tension can be reduced. Greatly improve. In order to maintain the resin pressure within the above range, a known pressure control device (A) 13 such as a gear pump, a pressure adjusting valve, a choke bar, or the like can be employed at the downstream end 9 of the first extruder. In order to maintain the resin pressure in the above range, it is preferable to adopt a single screw extruder for the first extruder.

  The screw shape of the first extruder 1 is not particularly limited, but a screw provided with a ring having a small clearance from the barrel, unimelt or the like before the carbon dioxide supply unit 8 is preferable. If the added amount of carbon dioxide is an appropriate amount and the thermoplastic resin is in a completely molten state, no back flow of carbon dioxide to the hopper 11 side occurs due to the melt sealing of the molten resin itself.

  Since the temperature in the first extruder 1 varies depending on the type, combination, blend ratio, added amount of carbon dioxide, required physical properties of the desired thermoplastic resin blend 7, the apparatus used, etc. Although not determined, it is usually desirable to set the temperature in the range of 50 to 400 ° C.

  The molten thermoplastic resin uniformly and finely dispersed by the first extruder 1 is then transferred to the connecting pipe 2. In this connection pipe 2, the resin pressure is controlled to be equal to or lower than the resin pressure in the first extruder. The pressure in the connecting pipe 2 is preferably 0 to 20 MPa. This pressure can be controlled by a pressure control device (B) 14 such as a pressure control valve installed at the tip of the connecting pipe 2, the temperature of the connecting pipe 2, the screw speed of the second extruder 3, and the like.

  Next, the molten thermoplastic resin passes through the pressure control device (B) 14, and preferably has a resin pressure of 0 to 7 MPa, more preferably 0 to 5 MPa, still more preferably 0 to 3 MPa, and particularly preferably 0 MPa. 2 Transferred to the extruder 3. The main function of the second extruder 3 is to degas carbon dioxide from the molten thermoplastic resin. At this time, low molecular weight components such as oligomers and impurities contained in the thermoplastic resin simultaneously with carbon dioxide can be removed.

  The cylinder of the second extruder 3 is provided with one or more downstream deaeration ports 5 sequentially from the supply port 4 connected to the connection pipe 2 toward the downstream side, and the supply port One or more upstream deaeration ports 6 are provided on the upstream side of 4. As the degassing method, a known degassing method such as an open degassing method that is naturally open or a forced degassing method using the vacuum pump 15 or the like can be employed. In the case of the forced deaeration method, it is preferable that adjusting means such as a flow rate adjusting valve and a flow rate adjusting nozzle are installed in order to adjust the deaeration capacity.

  There is no restriction | limiting in particular in the 2nd extruder 3 which can be used in this invention, The well-known extruder used for the resin processing method can be used. For example, a single screw extruder with one screw, a twin screw extruder with two screws, a multi-screw extruder with three or more screws, and the like are not particularly limited. Among them, a twin screw extruder that is easy to maintain the resin pressure in the cylinder at a low pressure and is advantageous for degassing is preferable. In the case where the deaeration is sufficiently possible (for example, when the amount of carbon dioxide added is small), a single screw extruder that is advantageous in terms of equipment investment cost, maintenance, etc. is preferable.

  The molten thermoplastic resin from which carbon dioxide has been completely removed by the second extruder 3 is molded into a predetermined shape via the die 16. There is no restriction | limiting in particular about the die | dye 16 used for this invention, A well-known die | dye can be employ | adopted. For example, a T die, an inflation die, a strand die, a pipe die, a modified die and the like can be mentioned.

  Moreover, the product shape manufactured by the manufacturing method of the present invention is powder, pellet, film, net, sheet, rod, filament, pipe, tube, plate, square, columnar Etc., not particularly limited.

  The method for supplying carbon dioxide is not particularly limited, and a known method can be adopted. For example, a method of supplying a gas state from a carbon dioxide cylinder through a pressure reducing valve and controlling a pressure of a supply unit, or a flow rate from a carbon dioxide cylinder 17 via a carbon dioxide metering pump 18 to control a liquid state or For example, a method of supplying in a supercritical state. Among these, a method of supplying in a supercritical state is preferable.

  As an example of a supercritical carbon dioxide supply method, the carbon dioxide in the liquefied carbon dioxide cylinder 17 is injected into the carbon dioxide metering pump 18 while maintaining the liquid state, and the discharge pressure of the carbon dioxide metering pump 18 is changed to carbon dioxide. After discharging while controlling with the pressure-holding valve 19 so as to be a constant pressure within the range of the critical pressure (7.4 MPa) to 50 MPa of carbon, the first extruder 1 is passed through the valve (A) 20 while maintaining the supercritical state. The method of supplying in the 1st extruder 1 from the carbon dioxide supply part 8 provided in 1 is mentioned.

  The thermoplastic resin used in the present invention can be used without any particular limitation. For example, low density polyethylene, high density polyethylene, medium density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer, propylene-butene copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic Acid copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ionomer resin (eg, ethylene-methacrylic acid copolymer ionomer resin), homopolypropylene, random polypropylene, block polypropylene, ultrahigh molecular weight polypropylene, polybutene, 4-methylpentene -1 resin, special polyolefin resin such as cyclic polyolefin resin, ethylene-styrene copolymer, styrene resin (polystyrene resin) Butadiene-styrene copolymer (HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), etc.), polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyacetal, polyphenylene oxide, polyvinyl acetate, Polyvinyl alcohol, polymethyl methacrylate, cellulose acetate, polyester (for example, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, etc.), polyamide resin, polyimide resin, fluororesin, polysulfone, polyethersulfone, polyarylate, polyetherether Ketones, liquid crystal polymers, thermoplastic polyurethanes, thermoplastic elastomers, biodegradable polymers (eg poly milk Hydroxycarboxylic acid condensate such as, thermoplastic resins composed of two or more resins of the condensate, etc.) and the like of a diol and a carboxylic acid such as polybutylene succinate.

  Further, in the present invention, in the resin, pigments, dyes, lubricants, antioxidants, fillers, stabilizers, flame retardants, antistatic agents, anti-ultraviolet agents, crosslinking agents, as long as the purpose is not impaired as necessary. An agent, an antibacterial agent, a crystal nucleating agent, a shrinkage preventing agent, and the like can be added.

  As another aspect of the present invention, an embodiment in which a low molecular organic compound is further added will be described with reference to FIG. 2 showing a system diagram.

  Depending on the type, combination, and blend ratio of the thermoplastic resin, a low molecular organic compound is added together with carbon dioxide at a ratio of 0.01 to 50 parts by weight with respect to 100 parts by weight of the total amount of the thermoplastic resin in the molten state. It may be more preferable to do. By adding a low-molecular-weight organic substance together with carbon dioxide as an auxiliary agent, the dispersion state of the obtained thermoplastic resin blend 7 may be more uniform and finer than the low-molecular-weight organic compound-free product. is there.

  The reason for this is not clear, but by selecting and adding the type and amount of low molecular weight organic compound that is optimal for the type, combination, and blend ratio of the thermoplastic resin, it can be reduced by melt blending under optimal molding conditions. It is presumed that molecular organic compounds promote a kind of compatibilizing effect.

  The low molecular organic compound used in the present invention can be used without particular limitation. As described above, it is preferable to select a low molecular weight organic compound that is optimal for each condition such as the type, combination, and blend ratio of the thermoplastic resin. Especially, the low molecular organic compound which consists of 1 type or 2 or more types of the group which consists of C1-C5 alcohol, alkanes, carboxylic acids, ethers, acetone, and benzene is preferable. In particular, ethanol is preferable from the viewpoint of safety to human bodies and foods, and from the viewpoint of cost performance, denatured ethanol used for industrial use is preferable. There are no particular limitations on the denaturing agent for denatured ethanol as long as it is a known one such as methanol, lactic acid, benzene, or ether.

  The method for supplying the low molecular organic compound is not particularly limited, and a known method can be adopted. For example, the low molecular organic compound 25 is fed and joined from the low molecular organic substance line 27 to the carbon dioxide line 24 via the valve (B) 28 by the metering pump 26. After the carbon dioxide and the low molecular organic substance are merged and mixed, the carbon dioxide is supplied into the first extruder from the carbon dioxide supply unit 8 provided in the first extruder 1 via the valve (A) 20.

  The addition amount of the low molecular weight organic compound is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the thermoplastic resin. In addition, the addition method of the low molecular organic compound is not particularly limited, such as a method of directly supplying to the molten thermoplastic resin, a method of adding to the thermoplastic resin before being supplied to the first extruder, and uniformly mixing. Not.

  By supplying carbon dioxide and a low molecular weight organic compound in this way, the molten thermoplastic resin is mixed with carbon dioxide and a low molecular weight organic compound, and the carbon dioxide and the low molecular weight organic compound are dissolved and diffused in the thermoplastic resin. To do. The subsequent manufacturing method is the same as that described in FIG.

  Next, the present invention will be described with reference to examples and comparative examples. The average number of bubbles described in Examples and Comparative Examples was measured according to the following method.

  A film having a thermoplastic resin blend thickness of 100 μm was continuously produced by extrusion film forming, and three 100 mm square film samples were obtained every 30 minutes. The number of bubbles that can be confirmed with the naked eye on the three film samples was counted, and the average value of the three points was taken as the average number of bubbles.

Example 1
A thermoplastic resin blend was produced by the apparatus shown in FIG. A Henschel mixer as the mixer 11, a single screw extruder (L / D = 28) with a screw diameter of 20 mm as the first extruder 1, a gear pump as the pressure control device (A) 13, and a second screw screw with a diameter of 30 mm as the second extruder 3. A coat hanger type T-die was used as a screw extruder (L / D = 40) and die 16. The carbon dioxide supply unit 8 is provided in the vicinity of the center of the first extruder 1, and the deaeration ports are downstream from the supply port 4 connected by the connecting pipe 2 of the cylinder of the second extruder 3 toward the downstream side. A side deaeration port (a deaeration port 5a (upstream side), a deaeration port 5b (downstream side)) and one upstream deaeration port 6 are provided upstream of the supply port. The downstream deaeration port 5 a and the upstream deaeration port 6 are open degassing methods, and the downstream degassing port 5 b is a forced deaeration method using a vacuum pump 15.

  First, 70 parts by weight of polypropylene (J103WB manufactured by Mitsui Chemicals, Inc.) is used as the thermoplastic resin (A) 10a, and 30 parts by weight of polystyrene (G899 manufactured by Nippon Polystyrene Co., Ltd.) is used as the thermoplastic resin (B) 10b. The mixture was sufficiently mixed by a machine to obtain a thermoplastic resin mixture.

  Next, this resin mixture was supplied from the hopper 12 to the first extruder 1 and dissolved by heating at 200 ° C. Carbon dioxide was extracted directly from the liquid phase portion using a siphon type liquefied carbon dioxide cylinder 17. The flow path from the liquefied carbon dioxide cylinder 17 to the carbon dioxide metering pump 18 is cooled with an ethylene glycol aqueous solution adjusted to −12 ° C. by the refrigerant circulator 21, and the carbon dioxide is sent to the carbon dioxide metering pump 18 in a liquid state. I was able to liquid. Next, the carbon dioxide metering pump 18 was controlled while confirming directly with the mass flow meter 22 so that the liquid carbon dioxide fed was 0.25 kg / hour. The discharge pressure of the carbon dioxide metering pump 18 was adjusted by the pressure-holding valve 19 so as to be 30 MPa, and carbon dioxide was supplied into the first extruder 1. The molten resin pressure of the carbon dioxide supply unit 8 at this time was 20 MPa. In this way, carbon dioxide was supplied to the first extruder 1 at a ratio of 16 parts by weight with respect to 100 parts by weight of the total amount of the molten thermoplastic resin, and was uniformly dissolved and diffused with a screw. It controlled by the temperature of the gear pump 13 and the connecting pipe 2 so that the pressure in the 1st extruder 1 might be maintained at 20 MPa.

  Next, this molten mixture is sent to the connecting pipe 2 and the pressure is adjusted to 10 MPa by controlling the temperature of the connecting pipe 2, the pressure control device (B) 14 at the tip of the connecting pipe, and the screw speed of the second extruder 3. did. Then, this molten mixture was sent to the second extruder 3 to degas carbon dioxide and impurities from three degassing ports. The temperature of the 2nd extruder at this time was 200 degreeC.

  The molten thermoplastic resin from which carbon dioxide and impurities were degassed was extruded in a film form through a T die 16 connected to the outlet of the second extruder at an extrusion rate of 1.6 kg / hour. The extruded film-like thermoplastic resin blend 7 obtained a film molded body with a winder 23. The average number of cells in the obtained film molding was 0.

Example 2
The same operation as in Example 1 was performed except that a single screw extruder (L / D = 28) having a screw diameter of 30 mm was used as the second extruder 3. The average number of cells in the obtained film molding was 0.

Example 3
A thermoplastic resin blend 7 was produced using the apparatus shown in FIG. Ethanol was used as the low molecular organic compound. The ethanol was supplied from the ethanol line 27 to the carbon dioxide line 24 by the ethanol metering pump 26 and combined to supply ethanol at a ratio of 1 part by weight to 100 parts by weight of the thermoplastic resin. The supplied ethanol was degassed from the three degassing ports (5a, 5b, 6) together with carbon dioxide. Except for this operation, the same procedure as in Example 1 was performed. The average number of cells in the obtained film molding was 0.

Example 4
The same procedure as in Example 3 was performed except that a single screw extruder (L / D = 28) having a screw diameter of 30 mm was used as the second extruder 3. The average number of cells in the obtained film molding was 0.

Comparative example It implemented similarly to Example 1 except having used the 2nd extruder which does not provide the upstream deaeration port 6 in the cylinder upstream of the supply port 4 of the 2nd extruder 3 connected with the connection pipe 2. FIG. . The average film count of the obtained film molded body was 20.

  Resin having physical properties that could not be achieved by one kind of thermoplastic resin, because a thermoplastic resin blend having a good finely dispersed structure can be produced using different types of thermoplastic resins without adversely affecting the respective physical properties A molded body can be obtained.

It is a systematic diagram which shows the manufacturing apparatus which manufactures a thermoplastic resin blend by the manufacturing method of one Embodiment of this invention. It is a systematic diagram which shows the manufacturing apparatus which manufactures a thermoplastic resin blend by the manufacturing method of other embodiment of this invention. It is a systematic diagram which shows the manufacturing apparatus which manufactures the thermoplastic resin blend implemented by the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st extruder 2 Connecting pipe 3 2nd extruder 4 Supply port 5a, 5b Downstream side deaeration port 6 Upstream side deaeration port 7 Thermoplastic resin blend 8 Carbon dioxide supply part 9 1st extruder downstream end 10a Thermoplastic resin (A)
10b Thermoplastic resin (B)
11 Mixer 12 Hopper 13 Pressure Control Device (A)
14 Pressure control device (B)
15 Vacuum pump 16 Die 17 Carbon dioxide cylinder 18 Carbon dioxide metering pump 19 Holding pressure valve 20 Valve (A)
21 Refrigerating machine 22 Direct mass flow meter 23 Winder 24 Carbon dioxide line 25 Low molecular organic compound 26 Low molecular organic compound metering pump 27 Low molecular organic compound metering line 28 Valve (B)

Claims (5)

  Two or more types of thermoplastic resins are supplied to the first extruder and melted, and 2-200 parts by weight of carbon dioxide is added to the molten thermoplastic resin with respect to 100 parts by weight of the total amount. And the mixture is supplied from the front end of the first extruder to the second extruder through the connecting pipe. In the second extruder, the cylinder is provided upstream of the connecting pipe supply port. A method for producing a thermoplastic resin blend comprising degassing carbon dioxide from one or more degassing ports and one or more degassing ports on the downstream side to extrude a thermoplastic resin.   In the first extruder, 0.01 to 50 parts by weight of a low molecular organic compound is further added to the molten thermoplastic resin in a total amount of 100 parts by weight, and the cylinder of the second extruder The method for producing a thermoplastic resin blend according to claim 1, wherein degassing is performed together with carbon dioxide from a degassing port provided in the container.   The thermoplastic resin according to claim 2, wherein the low molecular organic compound is at least one compound selected from the group consisting of alcohols having 1 to 5 carbon atoms, alkanes, carboxylic acids, ethers, acetone, and benzene. Manufacturing method of resin blend.   The method for producing a thermoplastic resin blend according to any one of claims 1 to 3, wherein the resin pressure from the carbon dioxide addition part of the first extruder to the downstream end is 12 to 50 MPa.   The method for producing a thermoplastic resin blend according to any one of claims 1 to 4, wherein the first extruder is a single screw extruder.

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