JPH039811A - Manufacture of thermoplastic resin composition and its molding - Google Patents

Abstract

PURPOSE:To manufacture a thermoplastic resin composition within which particulates of submicron order are displaced in high density, by a method wherein gas is discharged while collecting the particulates into a moving layer by causing the gas containing the particulates having a specific particle diameter to come into contact with or collide with the moving layer of thermoplastic resin in a molten state and, thus, molten resin and the particulates are kneaded. CONSTITUTION:Gas is discharged while collecting particulates into a moving layer of molten resin by causing the gas containing the particulates having a particle diameter of not exceeding 10mum to come into contact with or collide with the moving layer of thermoplastic resin in a molten state, and thus, molten resin and particulates are kneaded. Then in succession to the kneading, a thermoplastic resin composition into which the particulates are dispersed is molded. The effect of the particulates compounded with thermoplastic resin is especially marked in such case that they are compounded with the thermoplastic resin in a large quantity fallen within a range of 5-40volume%. As the gas to used, air, nitrogen, carbon dioxide or a rare gas such as argon, preferably an inactive gas is suitable as working gas and a gas having the boiling point lower than the melting point of the thermoplastic resin is preferable. In such a case when a gas containing the particulates is collected by causing the same to collide with the molten resin, the spouting through a fine hole should be at a flow speed of at least 10m/sec., preferably 40-200m/sec.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a method for producing a functional composite material mixed with fine particles and molded into plastic products such as fibers, molded products, biaxially stretched films, etc. It provides:

(Conventional technology) Composite materials processed into molded products have traditionally been made of glass fiber,
Composites made by melting and kneading thermoplastic resins with fillers with a size of about 1 micron or more, such as carbon fibers and whiskers, are mainstream (for example, see Japanese Patent Application Laid-Open No. 61-277421). There is a problem with improving the impact resistance of products. On the other hand, when dispersing fine particles of titanium oxide, carbon black, magnetic materials, etc. with a size of about 1 micron or less, the mainstream method is to mix the fine particles during polymerization of thermoplastic resin and disperse them uniformly. Due to the high temperature of the system, the materials that are practically used are limited to fine particles with good heat resistance such as titanium oxide and carbon black, and in order to contaminate the polymerization equipment, special equipment is required and a large amount of cleaning is required. There are problems such as the need for labor and expense. A masterbatch method in which fine particles are kneaded at a high concentration is also well known, but it requires drying of the resin before kneading and drying of the masterbatch after kneading, which requires a large amount of energy and labor. Deterioration of the physical properties of molded products due to thermal history also poses a problem.

(Problems to be Solved by the Invention) Regarding the problem of molded products made from conventional composite materials, we have developed a composite material filled with submicron to micron-sized fine particles instead of the conventional filler of 10 to several tens of microns. There is a demand for technology to manufacture more advanced products, such as various molded products made from plastics, biaxially oriented films, sheets, and fibers made from composite materials that have never existed before. In other words, it is necessary to develop a new technology that integrates a powder process that handles submicron to micron-sized particles and a polymer process. Originally, powder processes and polymer processes are different technologies, and the creation of a technology that harmonizes them can be achieved by harmonizing pneumatic transport technology for submicron-sized particles and polymer processes. This requires a technology for collecting submicron particles that is compatible with polymer processes.

-II, in the powder process, dust collection using a bag filter is typical, for example, as an industrially implemented dust collection technique. However, it is not only difficult to achieve complete continuity as a powder process, but there are also problems such as moisture absorption and reaggregation of collected fine particles. For this reason, the problem to be solved by the present invention is to establish a new production technology that industrially and continuously collects submicron-sized particles and incorporates them into a polymer process.

(Means for solving the problem) As a dust collection technology for fine particles that can be incorporated into the polymer process, this problem can be solved by collecting dust using a moving layer of molten resin, which makes it possible to integrate the powder process and the polymer process. Became. That is, in the first aspect of the present invention, when melt-kneading a thermoplastic resin and fine particles, the particle size is 10 μm.
A gas containing the following fine particles is brought into contact with or collides with a moving layer of molten thermoplastic resin, and the gas is discharged while the moving layer of molten resin collects the fine particles, and the molten resin and the fine particles are kneaded. This is a method for producing a thermoplastic resin composition in which fine particles are dispersed. A second aspect of the present invention is a method for producing a molded article, which comprises molding a fine particle-dispersed thermoplastic resin composition following the kneading described above.

Thermoplastic resins used in the present invention include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6, nylon 66, and nylon 12, polyolefins such as polyethylene and polypropylene, vinyl chloride, polycarbonate, polyurethane, and BS resin. , and known thermoplastic resins such as copolymers and mixtures thereof.

The fine particles in the present invention are preferably 100° at room temperature.
C or less and the average particle size is 10 μm or less, preferably 0.01
Refers to solid particles of ~1 μm. For example, titanium oxide, calcium carbonate, silica, talc, lithopone, zinc oxide, mica, barium sulfate, alumina, kaolin, carbon black, tin oxide, glass beads, gold, silver, copper, iron, lead,
Metal powders such as aluminum, calcium silicate, zirconium oxide, zirconium carbide, ferrites such as γFe2O3 and chromium dioxide, antimony trioxide, antimony pentoxide, bromine compounds, facial cleansers, antibacterial agents, stabilizers, etc. "Practical Handbook of Additives"
, edited by Kunio Goto, and published by Kagaku Kogyosha in 1971.

The amount of fine particles blended into the thermoplastic resin is usually 50% by volume or less based on the resin granules, but in the present invention it is 1 to 50% by volume.
It is effective when incorporated in a large amount in the range of 5 to 40 volume %, especially in the range of 5 to 40 volume %.

The fine particles contained in the gas are transported by the gas to contact or collide with a moving layer of molten thermoplastic resin. A suction method, a low-pressure pumping method, and a high-pressure pumping method are used for gas transportation of fine particles. Properties of fine particles, mixing ratio of fine particles and gas (
Depending on factors such as weight concentration), air flow velocity, and transportation distance, gas source equipment such as Roots blowers and compressors, transportation pipes, solid
Select appropriate gas separation equipment, etc. Further, fine particles dispersed in a gas can be obtained by supplying the fine particles and gas to an ejector mechanism, for example, but airflow treatment using a jet mill or the like can yield airflow-dispersed fine particles with higher functionality. This is preferable because it can be pneumatically fed directly and continuously to the kneading process without being collected once. For example, there are methods in which drying and surface modification of a wet fine particle dispersion slurry are performed simultaneously using a jet mill, methods in which classification or surface modification and pulverization are performed simultaneously, and methods in which dry precision classification and pulverization are performed simultaneously in a jet mill. (Tokuko Sho 56-406
34, 55-39370, 58-898, 5
5-6433).

Gases used in the present invention include air, nitrogen, water vapor,
Examples include rare gases such as carbon dioxide and argon, preferably inert gases, and gases having a boiling point lower than the melting point of the thermoplastic resin are preferred. Also, when gas is heated and used,
This is preferable because the amount of gas used and the energy for heating the resin can be reduced.

The concentration of fine particles in the gas is usually 10 to 100,000 g/N
m3, in most cases 50 to 30,000 g/Nm". Also, the transport velocity (flow rate) of gas containing fine particles is usually 5 to 30,000 g/Nm".
100 m/sec, preferably 10-40 m/sec.

If the transport speed is low, it is unfavorable in terms of re-agglomeration of particles and clogging of pipes, while if it is high, it is unfavorable in terms of wear of equipment and pipes. The pressure of the transport gas is usually -1,0 to 10k.
g/cm" is used. When collecting gas containing fine particles by colliding with the molten resin, 10 m from the pore.
The injection is performed at a flow rate of at least 40 m/sec, preferably from 40 to 200 m/sec.

The moving layer of thermoplastic resin in the molten state is obtained by a mechanism whose function is to supply and discharge the melt of thermoplastic resin. For example, it can be easily obtained using a single-screw or two-wheel screw kneading extruder that feeds granular thermoplastic resin and melts and kneads it above its melting point, or it can be easily obtained using a piping or kneading tank equipped with a molten resin supply/discharge mechanism, or a stationary type. It can also be obtained by means of a tubular mixing device.

In the present invention, fine particles are collected by a method in which a gas containing fine particles is brought into contact with or collides with the moving layer of the molten resin, but the molten resin that has collected the fine particles is always moved in the direction of the subsequent process. Since it is updated, efficient and stable collection of fine particles is possible (the collection time is usually set to about 10 minutes or less, and in many cases to 3 minutes or less). In particular, it is preferable to inject a gas containing fine particles through the pores and collide with the gas at a flow rate of 10 m/sec or more, since the so-called inertial dust collection effect is effective.

Furthermore, for example, using a Laval tube or a Venturi tube, 4
The method of collecting by spraying at a flow rate of 0 m/sec or more is preferable because it can finely pulverize aggregated fine particles and requires less gas (easier). A method in which the particles are collected by being ejected along with an air flow containing particles of 2 seconds or more is preferable because the surface area of the molten resin is large and the particle collection efficiency and dispersibility are good.

The gas from which fine particles have been removed may be discharged from either the side of the part that supplies the melted thermoplastic resin (or granules) or the part that melts (or discharges) it, but is preferably done on the supply side. Do it with It is also possible to suction and discharge by applying negative pressure with a proa or the like.

In the present invention, the melt of the thermoplastic resin and the fine particles are kneaded using, for example, a mixing tank with stirring blades, a kneading extruder having a cylinder fitted with a screw or rotor (Revised Lithographic Chemical Engineering Handbook, pp. 916-919). (edited by the Chemical Engineering Society, Maruzen, published in 1986, reference). When the thermoplastic resin contains moisture or when it is desired to remove gas mixed in with melting and mixing, it is preferable to provide a vent hole and apply negative pressure or nitrogen flow for degassing. Furthermore,
In the case of polyester resin, nylon resin, polyethylene resin, etc., where the thermoplastic resin deteriorates or volatile substances are generated during melt-kneading, two or more screws with two or more vents rotating in the same or different directions are used. It is preferable to use a axial kneading extruder because it has a devolatilizing effect that can be operated under high vacuum.

The melt-kneaded fine particle-dispersed resin composition is extruded from an outlet provided at the tip of a cylinder and guided directly to a die for obtaining fibers, sheets or films, or a mold for obtaining molded products, or by other known methods. Shaped by or -
It is first made into chips or powder and then subjected to molding.

Next, the present invention will be explained with reference to device diagrams.

1 to 3 are schematic diagrams showing examples of arrangement of devices suitable for carrying out the present invention.

In FIG. 1, ■ is a cylinder of a twin-screw kneading extruder. Two screws 2 rotating in the same direction are fitted into this cylinder I. In the cylinder 1, a resin supply port A, a gas discharge port B, an inlet C1 for a gas containing fine particles, and two vent holes DI and D2 are arranged in order at intervals in the longitudinal direction of the cylinder 1. The resin supply port A is located at the upstream end of the cylinder 1, and the downstream end is the outlet 3. The screw 2 has a diameter of 65 mm, and the side toward the supply port has a 15 mm deep groove 2a, the melting start part is a kneading desk, and the deep groove becomes shallow 2d, the kneading part has a 4 mm shallow groove 2c, and the kneading part has a 4 mm shallow groove 2c. The outlet and inlet provided in the section and the vent hole are formed into a slightly deep groove 2d of 6+n+n. A heater (not shown) is attached to the cylinder. Also, the length of the deep groove portion 2a is 390 mm, ? 6 Melting start part 2b is 1
The shallow groove portions 2c and 2d including the exhaust port, inlet port, and vent portion are 1365 n'un.

A closed charging hopper for resin granules is attached to the resin supply port A via a chute. An intake blower is connected to the gas exhaust port B through a filter. Fine particles that have been pulverized by, for example, injecting heated nitrogen at a pressure of 5 kg/cm 2 and colliding with a reverse orbit are press-injected into the inlet C together with the heated nitrogen. A nitrogen flow device (not shown) is connected to the ventro D1, and a vacuum pump (not shown) is connected to the ventro D2.

Further, the cylinder outlet 3 is connected to a mouthpiece 6 having a slit hole through a gear pump 5, and when the resin composition is extruded from the slit hole onto a rotating cooling drum, it is cooled to obtain a sheet. Next, this sheet is biaxially stretched to form a film, which is then heat-set, cooled, and rolled up.

The film forming method is described in Japanese Patent Application Laid-Open No. 61-118746.
Well-known methods shown in No. 1, etc. can be applied. The resulting film is useful as a reflective photographic support.

The preparation of reflective photographic materials using the same film is also disclosed in JP-A-61-118746.

In Figure 2, ■ is the screw of a single screw extruder,
a supply port A for resin granules from the upstream side spaced apart in the longitudinal direction;
An inlet C for a gas containing fine particles, a gas exhaust port B, and a vent D are arranged in this order. Screw 2 has a diameter of 7
0mm, and the upstream side from the melting start point is 16+n+++
The melting start part gradually becomes a shallow groove 2b, the kneading part becomes a shallow groove 2c of 4 mm, and the inlet, exhaust port, and center part become a slightly deeper groove 2d of 6 mm. A heater (not shown) is attached to the cylinder.

A closed charging hopper for resin particles is attached to the resin supply port A via a chute (not shown), and a gas exhaust port B is connected to the resin supply port A.
An intake blower is connected through a filter to
A heated gas containing fine particles is pressurized into the inlet C, and a vacuum pump is connected to the Hentro D.

Further, the outlet 3 of the cylinder is connected to a spinneret 6' via a distribution pipe 4 and a gear pump 5, and the resin composition is extruded from the pores and wound up to obtain fibers.

In FIG. 3, a portion of the molten resin is first taken out from the transfer pipe 1 of the continuous polymerization apparatus (not shown), and is cooled by the cooler 2 and the refrigerant jacket of the transfer pipe, and then transferred to the kneader 3. Enter the kneading machine from entrance A. A gas containing fine particles is fed into the inlet C from a gas compressor, a fine particle feeding device, a crushing device, and a classifier, and the fine particles are collected and kneaded with the molten polyester. The kneading machine 3 is mainly composed of a biaxial kneading disk 4, and a refrigerant is passed through the outer jacket to suppress heat generation. The fine particle dispersed polyester resin extruded from the kneader 3 is
It is quantitatively sent to the polymerization reactor 6 side by a metering pump 5'. Therefore, the flow rate of the kneader 3 is controlled by the screw rotation speed so as to maintain the input pressure of the metering pump 5'. Inside the polymerization reactor 6, there is a two-shaft disc type stirrer 7,
The kneading action mainly involves securing a large surface area for reaction and exchanging positions. The paper tube 9 is connected to a vacuum device to maintain a high vacuum inside the reactor. In addition, in order to maintain the internal resin temperature appropriately, a heat medium jacket 8 is provided, and a temperature-controlled heat medium is passed through. Polycondensation is thus carried out under reduced pressure of 5 Torr or less and at a temperature range from the melting point of the thermoplastic resin to 300° C., thereby recovering the polymerization loss suffered in the kneading extruder.

Next, the fine particle dispersed polyester resin is pumped with a metering pump 5″
The liquid is sent to the molding device 10 by. 4 is a sectional view of the kneader 3, and FIG. 5 is a sectional view of the polymerization reactor 6.

FIG. 6 is a cross-sectional view of an example of the apparatus shown in FIG. 3 in which the molten resin is injected together with a gas containing fine particles, and the fine particles are collected by the injected molten resin and the molten resin on the screw.

(Example) The present invention will be explained below with reference to Examples.

Example 1 In the resin supply port A of the twin-screw kneading extruder shown in Fig. 1, Ivo, 74
83 kg of polyethylene terephthalate chips were supplied at 1 hour, and nitrogen containing anatase-type titanium oxide with an average particle size of 0.3 μm (concentration 0.5 kg/NII+3
, temperature 265°C, pressure 5kg/cm") and 34Nm'
/Introduced at the time. Cylinder temperature at deep groove part 210°C1
Melting start part 280°C, kneading part and vent part 280°C
After kneading with a nitrogen flow of 3.6 Nm" at 1 hour for the Ventro DI and 5 Torr for the Ventro D2, the mixture was extruded from a slit-type nozzle at 290°C onto a rotating cooling drum and rapidly cooled. 1.1 Amorphous sheet was obtained.

Next, this sheet was stretched 3.0 times in the machine direction at 100°C, stretched 3.0 times in the cross direction at 110°C, and then
After heat setting at 00°C, the film was cooled and rolled up. The resulting film was 125 μm thick, white and opaque, and had an IV of 0.64. Note that stretch forming could be performed continuously and stably.

The obtained film had a good white color with no coloration due to polymer decomposition by-products, and was extremely useful as a support for reflective photography.

Example 2 η to the resin supply port A of the uniaxial kneading extruder in FIG.

= 2.70 nylon 6 chips were supplied at 19.8 kg/hour, and the isoindolinone pigment C,1, Pigment Yellow 110 with an average particle size of 20 pm was supplied to the inlet C.
Nitrogen (50g/Nm',
A temperature of 250° C.) was introduced at a rate of 4 Nm′/h. Cylinder temperature: 180°C at deep groove part, 250° at melting start part
C, kneading section and vent section 260'
The undrawn yarn is extruded from a spinneret and oiled to produce 1
It was wound up at a speed of 000 m/min. Next, this undrawn yarn was
A 208 denier/96 filament spun-dyed nylon fiber was produced by double stretching. Note that the operations from kneading to stretching could be performed stably.

The obtained spun-dyed nylon fiber has a strength of 3.6 g/d and an elongation of 4.
It had a uniform coloration of 1%.

Example 3 The average molecular weight ff was added to the resin supply port A of the twin-screw kneading extruder in Figure 2.
180,000 polyethylene chips were supplied at a rate of 98 kg/hour, and air Y containing carbon black with an average particle size of 20 nm (concentration 50 g/Nl 113, temperature 150'
c) was introduced at 4ONm'/h. The cylinder temperature was set to 150°C in the deep groove part, 230°C in the melting start part, 240°C in the kneading part and vent part, and the vent holes Di and D2 were set to 1.
After kneading under reduced pressure to 0 Torr, the mixture was extruded, cooled, and formed into a sheet with a thickness of 0.6 nua. Next, the obtained sheet was hot-stretched 6.0 times in the machine direction and then 5.0 times in the transverse direction, and then wound up. The resulting film has a thickness of 20 μm
It was black, opaque, and uniformly colored.

Example 4 Polybutylene terephthalate chips (Mitsubishi Kasei 0,1 Tubadol 50
10) at 65 kgj, styrene-butadiene block copolymer chip (Denka Kagaku Kogyo ■Denka STI?160)
2) was supplied at 20 kg/hour and polystyrene bromide powder (Nissan Ferro Organic Chemical ■Pyrocheck 68PB) with an average particle size of about 0.2 mm was supplied at a rate of 15 kg/hour, and antigin trioxide with a particle size of 0.3 μm was supplied to the inlet C. Contains nitrogen (: a degree 5
00g/Nm', temperature 150°C) was introduced at a rate of 1ONm'/hour. The cylinder temperature was set at 150°C in the deep groove part, 240°C in the melting start part, and 260°C in the vent and kneading part.
Ventro D is kneaded under reduced pressure of 10 Torr and then extruded.3. OaaφX3. , it was made into a chip of OmmL.

Various test pieces were then injection molded under normal conditions.

Injection molding could be performed stably. In addition to a high degree of flame retardancy, the test piece also had excellent impact resistance.

Example 5 Using the apparatus shown in FIG. 3, IV O, 65, temperature 282
A portion of polyethylene terephthalate having a viscosity of about 3000° C. was taken out from the transfer tube of the continuous polymerization apparatus, and the temperature was heated to 270° C. using a cooler and fed to a kneader at a rate of 83 kg/hour.

Jet mill finely pulverized and classified average particle size 0.
Air containing 2 μm of anatase titanium oxide (concentration 10
0g/Nm', temperature 270°C5 pressure 4kg/cm2)
was introduced at a rate of 17 ONm'/hour. The cylinder temperature of the kneader was set at 270"C, and after kneading with a nitrogen flow in the Hentro, the liquid was sent to the polymerization reactor. The polymer temperature at the front and rear of the polymerization reactor was set at 280 °C and 285 °C. After reacting at a vacuum degree of 1.2 Torr and a residence time of 18 minutes,
A film was produced in the same manner as in Example 1.

The obtained film had a good whiteness of 0.66 and was excellent as a support for reflective photography.

(Effects of the Invention) As explained in detail above, the present invention provides a new technique for producing thermoplastic resin compositions and molded articles in which fine particles of 10 μm or less, particularly submicron-level particles, are dispersed at a high concentration. It is. In other words, according to the present invention, it is possible to carry out the melt-kneading process of fine particles directly connected to the polymerization process and the molding process, thereby significantly improving quality, cost, and productivity, which were difficult to solve with conventional methods. I can do it. The method of the present invention is also suitable for high-mix, low-volume production, and provides an industrially extremely useful polymer process.

[Brief explanation of the drawing]

Figures 1 to 3 are schematic diagrams showing examples of arrangement of equipment suitable for carrying out the method of the present invention, Figure 4 is a sectional view of a kneader, Figure 5 is a sectional view of a polymerization reactor, and Figure 6 is a sectional view of a polymerization reactor. , FIG. 3 shows an example in which molten resin is injected together with a gas containing fine particles. Figure 2 Figure 4 Figure 5 Figure 6 Procedure amendment document June 27, 1989

Claims (1)

[Claims] 1. When melt-kneading a thermoplastic resin and fine particles, a gas containing fine particles with a particle size of 10 μm or less is caused to contact or collide with a moving layer of molten thermoplastic resin to move the molten resin. A method for producing a fine particle-dispersed thermoplastic resin composition, which comprises discharging gas while collecting fine particles in a layer, and then kneading the molten resin and the fine particles. 2. A method for producing a molded article, which comprises molding the fine particle-dispersed thermoplastic resin composition subsequent to the kneading according to claim 1. 3. The method according to claim 1, characterized in that the gas containing fine particles is caused to collide with the moving bed of molten resin at a flow rate of 10 m/sec or more.