JPS60214919A - Molding of polymer - Google Patents

Abstract

PURPOSE:To take out quantitatively clean polymers directly from the main outlet for polymers by a method in which the discharge amount of a polymer from the polymer outlet of a degassing extruder is controlled to regulate the pressure of a resin in the extruder. CONSTITUTION:Crude polymer is deprived of its volatile and solvent components by a screw 3 through a vent port 4 by suction and sent to near a polymer outlet 5. The polymer near the outlet 5 is taken out of a polymer discharge amount regulator 11 through the main polymer outlet 8 and the polymer outlet 5 and immediately soon supplied to dies 12 and 12' for molding. By the regulator 11, the resin pressure P of the degassing extruder 1 and the revolving number of the driver for the regulator 11 are controlled in an interlocking manner, thereby making the resin pressure P constant. The treated clean polymer can thus be continuously supplied to the dies and the polymer of stable quality can be obtained.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is a method of continuously volatilizing a crude polymer obtained by bulk polymerization or solution polymerization using a devolatilizing extruder, and then continuously converting it into a certain stable shape. The present invention relates to a method for obtaining a molded article, and particularly relates to a method for continuously obtaining a molded article with a stable shape, even if new minute foreign matter increases in the polymer to be molded.

[Conventional technology]

Conventionally, the method for obtaining precise molded products in the form of fibers, films, and sheets from crude polymers was extrusion using a devolatilizing extruder. l (IJ Mama - The method of directly introducing it into the molding die is not carried out, and as shown in Fig. 1, the crude polymer is fed from the raw material 2 of the devolatilizing extruder 1, mixed and conveyed by the screw 3, After the contained volatile matter and solvent are removed by suction from the vent 4, the polymer is sent to the polymer outlet 5.The polymer sent to the polymer outlet 5 is continuously extracted in fixed amounts by a quantitative extraction device 10. , is immediately supplied to the molding die 11 and molded.At this time, the resin pressure in the devolatilizing extruder is controlled by the rotational speed of the drive part M1 of the screw 3 according to the instruction from the resin pressure gauge P attached to the polymer discharge port 5. Control is achieved by changing the

〔problem〕

In the above method, since the treated polymer is supplied to the molding die by the quantitative extraction device 10, fine dust (fine metal powder) generated by the abrasion of the shaft sliding surface and gears of the quantitative extraction device 10 is removed. There is a problem that the generated baked polymer is mixed into the treated polymer.

The present inventors have conducted various studies on polymer molding methods that do not have the above-mentioned problems. As a result, the present inventors used a conventional devolatilizing extruder equipped with a polymer discharge port and a polymer main outlet. By controlling the rotation speed of the drive unit of the discharge rate adjusting device to control the resin pressure in the extruder, the polymer without foreign matter is delivered to the polymer main outlet under a constant pressure and flow rate without passing through the discharge rate adjusting device. The present invention was completed by discovering that it is possible to extract 11 tangents from

Optical applications of contamination-free polymers concern resin raw materials that require a high degree of dust exclusion for optoelectronics, such as POF.

These products include optical discs and dustproof films for photomasks.

〔composition〕

That is, the present invention devolatilizes a crude polymer mainly composed of methyl methacrylate or styrene containing volatile impurities using a devolatilizing extruder, and then continuously extracts the polymer.
In a method for forming trash-free fibers, films, and plates for subsequent use in optical applications, the devolatilizing extruder is provided with a polymer outlet and at least one main polymer outlet; By adjusting the amount of polymer discharged from the polymer outlet of the devolatilizing extruder, the resin pressure inside the devolatilizing extruder is adjusted, and the uncontaminated polymer is quantitatively taken out from the main polymer outlet, and then transferred to the molding die. This is a method of molding a polymer by supplying it to a polymer and molding it.

The present invention will be explained in detail below.

The crude polymer used in the present invention is methyl methacrylate containing volatile impurities (e.g., unreacted monomer, solvent, etc.) produced by bulk polymerization or solution polymerization;
Examples include transparent polymers mainly composed of styrene.

The devolatilizing extruder used in the present invention is shown in FIGS.
), a conventionally used devolatilizing extruder is provided with a polymer outlet 5 and at least one polymer main outlet 8, and polymer free from contamination and foreign matter is taken out from the polymer main outlet 8. The polymer discharge port 5 is designed to discharge the polymer containing contaminants and foreign substances generated at the support part 6' of the screw 3, and to extract the polymer for controlling the resin pressure inside the devolatilizing extruder. be.

The discharge rate adjusting device used in the present invention can employ a conventionally used discharge rate pump, such as a normal gear pump or a gear pump for polymers. Because it is stable, it is convenient for obtaining high-precision molded products. Therefore, by utilizing this effect, the discharge amount can be changed over time by controlling fluctuations in the polymer pressure inside the devolatilizing extruder in conjunction with the rotation speed of the drive unit of the discharge amount adjustment device.When the resin pressure is high, the discharge amount can be adjusted. The amount of polymer discharged from the polymer outlet is adjusted by increasing the rotation speed of the device and lowering the rotation speed of the discharge amount adjustment device when the resin pressure is low, thereby maintaining the resin pressure inside the devolatilization extruder at a constant pressure with high precision. You can.

The molding die used in the present invention may be any of the commonly used molding dies for pelletizing, sheet (or embossed plate) molding dies, and fiber molding dies. In particular, a molding die for fibers is preferred as a molding die for obtaining a polymer free from contamination.

An embodiment of the polymer molding method of the present invention will be explained with reference to FIG.

In Fig. 6, 1 is a devolatilizing extruder, 2 is a raw material receiving port, and 3 is a devolatilizing extruder.
is screw, 4 is ventro, 5 is polymer outlet, 6
．． 6' is a support part for the screw 3, 7 is a cylinder, 8 is a polymer main outlet, 9 is a polymer waste port, 11 is a discharge amount/adjustment device, and 12.12' is a molding die. crude,)
(+77- is continuously supplied into the devolatilizing extruder from the raw material supply port 2 of the devolatilizing extruder 1, and the supplied crude polymer is mixed and stirred by the screw 3 and the volatile content is (e.g., 7-dose) and the narcotic are separated and removed by suction from the vent 4, and sent to the vicinity of the front reamer outlet 5.Then, the polymer sent to the vicinity of the polymer outlet 5 is transferred from the main polymer outlet 8. After being extracted from the polymer discharge amount adjusting device 11 via the polymer discharge port 5, the polymer is immediately supplied to the molding die 12, 12', and then molded.

The polymer discharge rate adjusting device 11 controls the resin pressure P of the devolatilizing extruder 1 and the rotation speed of the drive unit of the polymer discharge rate adjusting device 11 in an interlocked manner, thereby keeping the resin pressure P constant and discharging the polymer from the main polymer outlet 8. obtains a contamination-free polymer with good moldability at a constant flow rate. Further, contaminants generated in the support section 6 are disposed of together with the polymer through the polymer waste port 9 at atmospheric pressure or higher or lower, and contaminants in the support section 6' are taken out via the polymer discharge rate adjusting device 11.

〔Example〕

Example 1 5 k of crude polymethyl methacrylate containing about 46 parts of unreacted methyl methacrylate and 10 parts of ethylbenzene
g/Hr was continuously treated using a devolatilizing extruder supported by screws at both ends as shown in FIG.

Crude polymethyl methacrylate containing unreacted monomers and ethylbenzene was continuously fed into the extruder 1 through the inlet 2, and 10 g of the total polymer amount and 1 g of the polymer were discarded from the polymer waste port 9 and the vent 4 of the extruder 1. together with the discharge amount adjusting devices f11 to 6 via the polymer discharge port 5.
A 60% contaminant-free polymer was obtained from the polymer main outlet 8 and the polymer main outlet 8. In order to measure the degree of contamination of these polymers, we measured the scattering intensity of the molten polymer obtained from the discharge rate adjustment device and the main polymer outlet.
It was collected directly into a heated glass tube, annealed at 120°C% for 5 hours, cooled, the glass tube was removed, and a diameter of 2.
A sample rod of 5 ioa was manufactured, and the light scattering intensity of this rod was measured.

The scattering intensity was determined by irradiating the center of the rod with 633 nm He-Ne radar light and measuring the scattering intensity in a direction of 90° from the irradiated light. The results are shown in Table-1. The degree of contamination was compared by evaluating the specific scattering intensity with respect to a standard sample manufactured by the following method.

Manufacturing method for the standard sample: The standard sample was prepared by removing dust from benzene using a known method and then sealing it in a Pyrex glass tube with an inner diameter of 25 mm and a wall thickness of 2 mm. The scattering intensity was measured using a single beam, and the value at this time was set as 1.0.

Standard samples are shown as values of light scattering intensity of benzene and glass tube.

Table - 1633 nm (He-No radar light) Example 2 Using the discharge rate adjustment device at the tip of the devolatilizing extruder used in Example 1, the resin pressure and the rotation speed of the drive unit of the discharge rate adjustment device are linked and controlled. The quality of moldability under constant pressure was compared. The molded polymer has a diameter of 1. otxm fiber was used, and the polymer wire diameter was continuously recorded using a Rede one-type non-contact measuring device to compare the quality of moldability. The results are shown in Table-2. For comparison, the discharge rate adjusting device was removed and the variation in fiber wire diameter was examined under conditions where approximately the same wire diameter could be obtained depending on the pulp, and the results are also shown in Table 2. The wire diameter variation was within ±3.0 degrees when controlled by the discharge amount adjustment device, whereas it was +14 degrees when the discharge amount adjustment device was not used.

(Remaining color below) Table 2 (Tensile speed 1QM/m1n) [Effect] According to the method of the present invention, the treated polymer without contamination is continuously supplied to the molding die without passing through the polymer discharge rate adjusting device. By controlling the rotational speed of the drive unit of the polymer discharge amount adjusting device and the resin pressure of the devolatilizing extruder in conjunction with each other, it is possible to obtain a polymer with a stable shape and no contamination.

[Brief explanation of drawings]

Figure 1 is a schematic process diagram for explaining a conventional polymer molding method, Figure 2 is a schematic diagram of a devolatilizing extruder used in the method of the present invention, and Figure 2 (A) is a schematic diagram of its embodiment. Figure, 2nd
Figure fB) is a schematic diagram of another embodiment, and Figure 6 is a schematic process diagram of the method of molding the polymer of the present invention. In the figure: 1 is the devolatilizing extruder, 2 is the raw material intake, 3 is the screw, 4 is the vent, 5 is the polymer outlet, 6.6' is the screw support, 7 is the cylinder, 8 is the main polymer outlet, 9 is a polymer waste port, 10 is a quantitative extraction device, 11 is a discharge amount adjusting device, 12° 12' is a molding die, Ml is a screw drive unit, M. P indicates the drive unit of the quantitative extraction device and the discharge amount adjustment device, and P indicates the resin pressure gauge. Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] 1. After devolatilizing a crude polymer mainly composed of methyl methacrylate or styrene containing volatile impurities using a devolatilizing extruder, the polymer is continuously extracted to produce a dust-free fiber that is subsequently used for optical applications. In the method for forming films and plates, the devolatilizing extruder is provided with a polymer outlet and at least one polymer main outlet, and the amount of polymer discharged from the polymer outlet of the devolatilizing extruder is adjusted. By doing so, the resin pressure in the devolatilizing extruder is adjusted, and the polymer without contamination is quantitatively taken out from the main polymer outlet and supplied to the molding die for molding. i(+7mer molding method 2) A patent characterized in that a gear pump equipped with a motor that is linked to the resin pressure is used to adjust the resin pressure in the devolatilizing extruder to adjust the amount of polymer discharged from the polymer discharge port. A method for molding a polymer according to claim 1.