JP2007084778A - Continuous granulation apparatus for high-melt tension polyethylene terephthalate-based polyester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuous granulation apparatus for pelletizing a high-melt tension polyethylene terephthalate-based polyester under a specific condition stably for a long period. <P>SOLUTION: The dehumidification of a cylinder, and the improvement of a die shape and a screw shape are performed when a mixture constituted of (a) a PET-based polyester, (b) a mixture of a tri- or polyfunctional epoxy compound and a bifunctional epoxy compound as a binder, and (c) a metal salt of an organic acid as a catalyst is subjected to a reaction extrusion method to modify the polyester to provide a high-melt tension product. The granulated pellets of the high-melt tension polyethylene terephthalate-based polyester enable new molded products such as a foam, a tubular-method film, a direct blow-method bottle and a pipe the molding of which is difficult by a conventional PET resin. As a result, the pellets are useful in the fields of daily necessity, civil engineering and construction, electric and electronic goods, a trim material for an automobile or the like such as a packaging film and an industrial material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a continuous granulator for stably pelletizing a high melt tension polyethylene terephthalate polyester under specific conditions for a long period of time.

  So far, polyvinyl chloride (PVC, PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET or PET), etc., have been used as appropriate materials as the five large-scale general-purpose resins. I came. These materials have advantages and disadvantages with respect to molding processability, quality, price, environmental compatibility, and the like.

Polyethylene terephthalate is used in large quantities as stretch blow PET bottles due to its high quality properties, and A-PET sheets are also excellent in transparency, rigidity and environmental compatibility, so food packaging materials, food containers, and IT materials Applications of daily necessities such as blister packs are expanding rapidly. In particular, used bottles, films, sheets, etc. of used pets are being actively collected and reused in large quantities, and can be obtained in large quantities at a low price of half the price of general-purpose resins.
The present inventors are mainly composed of recovered PET bottles and flakes that can be obtained at half the price of general-purpose resins and recovered PET sheets or fiber pets obtained at low cost by the polycondensation method, with an epoxy binder and an organic acid metal catalyst. It was proposed to produce a high molecular weight, high melt tension resin by reactive extrusion.
Japanese Patent No. 3503952 In addition, the present inventors have disclosed that the gel and fish eye (FE) are easily produced as a by-product due to a heterogeneous reaction because the reactive extrusion method is a high-speed reaction. As a countermeasure, we proposed a solution by masterbatching epoxy binder and organic acid metal catalyst. WO 2001/94443

An object of this invention is to provide the continuous granulation apparatus which pelletizes high melt tension polyethylene terephthalate-type polyester stably for a long term on specific conditions.
However, if granulation operation is performed for a long time using a commercially available extrusion device, the melt flow rate (MFR) rises, the strands on both ends of the die destabilize and cut, the resin yellows, the screw browns and becomes dirty. Etc. have arisen. In any case, it has not reached the practical level.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in improving the above-mentioned problems and have completed the present invention.

That is, the present invention provides the following invention items.
(1) Component A: 100 parts by weight of polyethylene terephthalate polyester
Component B: Mixture in which the weight ratio of compound a containing 2 epoxy groups in the molecule to compound b containing 3 or more epoxy groups in the molecule as a binder is 95-40 to 5-60 0.1 ~ 2 parts by weight,
Component C: A raw material mixture D composed of 0.05 to 1 part by weight of a metal salt of an organic acid as a catalyst is melted at a temperature equal to or higher than its melting point and uniformly reacted by reactive extrusion while degassing and dehydrating under vacuum. By high-strength polyethylene terephthalate polyester having a melt flow rate of 20 g / min or less and a swell of 1 to 200% according to JIS method (280 ° C., load 2.16 Kg), pelletized stably for a long time under specific conditions. A continuous granulator characterized by.
(2) A high melt tension polyethylene terephthalate polyester is stably pelletized for a long period of time by installing a conduit for releasing water vapor into the atmosphere in a hopper that supplies the raw material mixture D to the screw of the reaction extruder. A continuous granulator.
(3) Continuously characterized in that a high melt tension polyethylene terephthalate polyester is stably pelletized for a long period of time by installing a nozzle having an inner diameter of 1 to 5 mm and a protruding length of 0.5 to 10 mm in a die of a reaction extruder. Granulator.
(4) A high melt tension polyethylene terephthalate polyester is stably pelletized for a long time by using a caliber / groove pitch ratio of 100 / 30-60 and a mixing zone of 2-4 as a single screw of a reaction extruder. The continuous granulation apparatus according to any one of claims 1 to 3, wherein:

  Polyethylene terephthalate (PET) polyester, which has high melt tension, is formed as a long-chain branched structure with a mixed binder and catalyst, using PET with a medium molecular weight as the main raw material. Grain was difficult. However, since the high melt tension pellets were produced by the new granulating apparatus according to the present invention, new applications, such as foam molding, tubular film molding, pipe molding, etc., which were difficult with conventional PET resins, became possible. .

BEST MODE FOR CARRYING OUT THE INVENTION

The raw material components and the reactive extrusion method in the present invention are described in detail in the prior invention of the present inventors.
Examples of the component A polyethylene terephthalate (PET) polyester include polyethylene terephthalate (PET or PET) or a copolymer thereof mass-produced worldwide as a PET aromatic polyester. Polyethylene terephthalate is particularly preferred, but has an intrinsic viscosity (IV value) of 0.50 dl / g or more (this corresponds to an MFR of about 210 g / 10 min or less at JIS method, temperature of 280 ° C. and load of 2.16 kg). Although it can be used, it is preferably 0.60 dl / g or more (MFR is about 130 g / 10 min or less). If the intrinsic viscosity is less than 0.50 dl / g, it is difficult to achieve a high molecular weight and a high melt viscosity even according to the present invention, or it may not always be possible to provide excellent moldability and physical properties. The upper limit of the intrinsic viscosity is not particularly limited, but is usually 0.90 dl / g (MFR of about 25 g / 10 min or less), preferably 0.80 dl / g (MFR of about 45 g / 10 min or more).

  In reality, PET-based polyester PET bottle flakes, parison fragments or pellets that are collected and collected in large quantities are often used as prepolymers. Usually, since the intrinsic viscosity of PET bottles is relatively high, the intrinsic viscosity of the recovered product is also high, generally 0.60 to 0.80 dl / g (MFR 130 to 45 g / 10 min), especially 0.65 to 0.75 dl / g (MFR 100 to 55 g / 10 min). Generally, the recovered PET bottle flakes are supplied in a 20 kg paper bag product and a 600 kg FIBC product, but the water content is usually about 3,000 to 6,000 ppm (0.3 to 0.6% by weight). . Of course, skeleton flakes of A-PET sheets recovered in large quantities from a vacuum / pressure forming factory are also suitable as the raw material polyester of the present invention.

  For food packaging materials, PET resin for fibers and fluff by polycondensation can be used. Usually, the intrinsic viscosity is 0.55 to 0.65 dl / g (MFR 200 to 130 g / 10 min), but 0.60 to 0.65 dl / g (MFR 130 to 100 g / 10 min) is preferable. .

The binder as B component of the present invention is a compound containing 2 (a) and optionally more than 3 (b) epoxy groups in the molecule.
Usually, examples of the compound a having an average of two epoxy groups in the molecule include aliphatic ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trilamethylene glycol di Glycidyl ether, tetramethylene glycol diglycidyl ether, 1,6-hexamethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin diglycidyl ether, and alicyclic hydrogenated bisphenol A diglycidyl Ether, hydrogenated isophthalic acid diglycidyl ester, aromatic bisphenol A diglycidyl ether, bisphenol A diglycidyl ether precondensate, diphenylmethane di It can be mentioned glycidyl ether, terephthalic acid diglycidyl ester, isophthalic acid diglycidyl ester and the like. Preferred are ethylene glycol diglycidyl ether, 1,6-hexamethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and glycerin diglycidyl ether.

Examples of the compound b having an average of 3 epoxy groups in the molecule include aliphatic trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, and heterocyclic triglycidyl isocyanurate and triglycidyl cyanate. Examples thereof include nurate, triglycidyl hydantoin, and aromatic triglycidyl para- or meta-aminophenol.
As the industrial article, a mixture of compounds having an average number of epoxy groups of 2.1 to several in the molecule can be used. For example, a phenol novolak epoxy resin, a cresol novolak epoxy resin, and a biphenyl dimethylene epoxy resin (for example, Nippon Kayaku Co., Ltd. heat-resistant epoxy resin NC-3000 series) can be used. As another example, an average of about 2.2, 3.6, 3.8, and 5.5 epoxy groups in the molecule are marketed by Dow Chemical Company, and these can be used. . Trimethylolpropane triglycidyl ether and glycerin triglycidyl ether are preferred.

One of the features of the present invention is the selection of the binder. A compound containing two epoxy groups in the molecule (bifunctional: D) a as a binder and a compound containing three or more epoxy groups in the molecule (trifunctional or more: T) b are used in combination. By introducing a “long-chain branched structure” and increasing the T / D ratio, for example, the crystallization speed in vacuum / pressure forming of a sheet can be increased. This is presumed that a compound containing a tri- or higher functional epoxy group acts as a “molecular size crystallization nucleating agent”.
Further, the long-chain branched structure of the present invention can increase the melt viscosity by about 10 to 100 times due to the “entanglement effect” of the molecular chain as compared with the conventional linear structure. Therefore, it is possible to form foam, tubular method film, vip and the like, which is difficult with the conventional linear structure PET.
The epoxy group-containing compound B of the present invention is a compound (D) a containing two epoxy groups in the molecule: 100 to 0% by weight and a compound (T) containing more than three epoxy groups in the molecule b: 0 to 100 wt% mixture. The increase in the latter (T) causes the resin swell and melt viscosity to rise rapidly. The weight ratio (T / D ratio) of the latter / the former is usually 5/95 to 70/30, preferably 10/90 to 60/40, more preferably 12.5 / 87.5 to 50/50. . When the T / D ratio is 5/95 or less, the effect is small. When the T / D ratio is 60/40 or more, it is difficult to produce a PET-based polyester resin.

In addition, another feature of the present invention is that the substrate c is used as a diluent in order to prevent the local heterogeneous reaction of the binder B, which is a by-product of gel and fish eyes of films and sheets. It is to be used as an agent master batch d. The binder B is composed of 10 to 50 parts by weight of the mixture B and 100 parts by weight of the substrate c. The mixture B is preferably 15 to 25 parts by weight. When the binder B is 10 parts by weight or less, the effect of the master batch d is small and the cost is increased. If the binder B is 50 parts by weight or more, the master batch d is difficult to produce, and a gel is easily produced as a by-product in the reactive extrusion method.
Examples of the substrate c include polyethylene terephthalate polyester having an intrinsic viscosity of 0.60 to 0.80 dl / g, a recycled product of a recovered polyethylene terephthalate polyester molded article, and a condensate such as ethylene glycol, cyclohexane / dimethanol and terephthalic acid ( Eastman's PETG), toluene, benzene, xylene and the like can be used.

  The compounding ratio of the binder master batch d is usually 1 to 10 parts by weight with respect to 100 parts by weight of the raw material polyester A, but is preferably about 2 to 8 parts by weight with good dispersibility and mixing properties. As the ratio increases, the MFR of the PET-based polyester can be reduced, and the melt viscosity and swell can be increased.

The coupling reaction catalyst C in the present invention is a complex of a metal salt of a carboxylic acid and a masterbatch thereof. It has been found in the present invention that metal salts of carboxylic acids are not necessarily suitable for the purpose of stable granulation of the polyester of the present invention when used alone. Accordingly, the binding reaction catalyst C is preferably a composite. For example, as a binary catalyst, lithium stearate / calcium stearate = 20 / 80-50 / 100, sodium stearate / calcium stearate = 20 / 80-50 / 100, potassium stearate / calcium stearate = 20 / 80-50 / 100 Manganese acetate / lithium stearate = 20-50 / 100 or manganese acetate / calcium stearate = 20-50 / 100.
On the other hand, for example, as a three-way catalyst, lithium stearate / sodium stearate / calcium stearate = 50/50/100, potassium stearate / sodium stearate / calcium stearate = 50/50/100, lithium stearate / sodium acetate / stear A composite catalyst C such as calcium phosphate = 50/50/100 or lithium stearate / manganese acetate / calcium stearate = 50/50/100 is more preferable.

Another feature of the present invention is that the catalyst masterbatch f is utilized by using the substrate e as a diluent in order to prevent local reaction around the catalyst C, which is a by-product of gel and fish eyes of films and sheets. Is to use. As the substrate e, a polyethylene terephthalate aromatic polyester having an intrinsic viscosity of 0.50 to 0.90 dl / g, a recycled product of recycled polyethylene terephthalate aromatic polyester molded product, ethylene glycol and cyclohexane, almost the same as the substrate c -Condensates such as dimethanol and terephthalic acid (Eastman's Petzie, etc.) can be used.
When the above-mentioned resin is not used as the substrate e, calcium stearate white powder having a mild catalytic activity and having a lubricant effect can be used. The component ratio of calcium stearate is 50 parts by weight or more with respect to the catalyst. This white powder composite catalyst has the problem of workability of powder scattering, but is inexpensive and suitable for small-scale production.

The composition ratio of the catalyst master batch f is usually composed of 5 to 15 parts by weight of catalyst C and 100 parts by weight of substrate e, preferably 7.5 to 12.5 parts by weight of catalyst C, more preferably Is composed of 10 parts by weight of catalyst C and 100 parts by weight of substrate e. When the catalyst C is 5 parts by weight or less, the effect of the catalyst master batch f is small and the cost is increased. If the catalyst C is 15 parts by weight or more, the master batch f is difficult to produce, a gel is easily produced as a by-product in the binding reaction, and it causes hydrolysis of the resin during the molding process, which is not preferable.
The amount of the catalyst masterbatch f used is usually 0.25 to 10 parts by weight with respect to 100 parts by weight of the raw material polyester A, but preferably around 0.5 to 5 parts by weight with good dispersibility / mixability. It is.

Examples of the reactive extrusion apparatus include a single-screw extruder, a twin-screw extruder, a combination two-stage extruder, or a self-cleaning twin-screw reactor used for the production of polycondensation of PET resin. Can be used. Since the reactive extrusion method for producing the high melt tension PET polyester of the present invention is performed in a short time of about 2 to 10 minutes, particularly in the extruder, the L / D of the extrusion reactor is about 30 to 50. Is preferable, and about 38 to 45 is particularly preferable.
According to the present invention, depending on the performance of the reactive extruder, the raw material polyester A generally has a residence time of a short time, for example, 1 to 20 minutes, preferably 2 to 10 minutes, particularly preferably 4 to 7 minutes. The molecular weight can be increased rapidly to produce the desired polyester.

The above-mentioned reaction extrusion apparatus generally has a recovered PET bottle flake or a new polyester resin dried in advance with hot air at 110 to 140 ° C. to a moisture content of 100 to 300 ppm, and dried with dehumidified air to a moisture content of 50 ppm or less. It is preferable to use the one lowered to. The polyester resin usually adsorbs humidity in the air and contains 3,000 to 6,000 ppm (0.30 to 0.60% by weight) of moisture according to the environmental humidity, and is thus dried as described above. To help achieve the object of the present invention stably.
The vacuum line of the single-screw or twin-screw extruder is oil-sealed or dry-type that is not non-water-sealed. For example, the vacuum degree of the first to third vents is 13.3 × 10 ³ Pa (100 mmHg) or less, preferably 2.6. X10 ³ Pa (20 mmHg) or less, more preferably 0.66 × 10 ³ Pa (5 mmHg) or less, and even more preferably 0.26 × 10 ³ Pa (2 mmHg). By removing residual moisture by vacuum degassing during mixing, the operation of continuous granulation is stabilized.

  However, when a granulation operation is performed for a long time using a commercially available extrusion apparatus, a phenomenon that the melt flow rate (MFR) increases to 2 to 3 times the set value has occurred. The raw material PET was dried with hot air to a moisture content of about 100 to 300 ppm, or dehumidified to 30 to 50 ppm, but sooner or later. The cause is that water vapor generated from the raw material PET heated in the cylinder between the bottom of the hopper and the first vent flows back to the hopper side and accumulates in the raw material PET, and this moisture is hydrolyzed in the reaction extruder. It was determined that this would cause a decrease in the molecular weight of the PET resin and an increase in MFR. This moisture cannot be completely removed by vacuum removal from the first vent hole. In particular, the phenomenon becomes remarkable when the supply rate of the raw material PET is increased. Therefore, it was found that a long-term stable granulation operation can be achieved by installing a conduit that can release water vapor into the hopper.

In the granulation operation of the high melt tension and high swell PET-based polyester of the present invention, the strands extruded from the nozzle holes arranged horizontally on the die are likely to be unstable and cut at both ends. In addition, since the swell is large, when the interval between the nozzle holes is normally arranged, the strands are easily attached to each other to form a single plate.
In the present invention, the nozzles are protruded from the die at an appropriate interval, for example, 5 to 20 mm to prevent the strands from sticking together. The direction of protrusion is horizontal, diagonally downward or vertically downward. The inner diameter of the nozzle is 1 to 5 mm, the wall thickness is 0.5 to 2 mm, and the length is 0.5 to 10 mm. The nozzle is screwed into the die.

In the reactive extrusion method, problems such as yellowing of the resin, blackish browning of the screw, and dirt have occurred. The yellowing of the resin is due to oxidative degradation of the resin due to air brought in from the raw material system. A single screw extruder can be compressed into a resin, and if used together with a vent, yellowing can be prevented by “squeezing and removing” air, which is superior to a twin screw extruder.
However, since the single screw extruder is inferior to the twin screw extruder in mixing performance, it is necessary to install 2 to 4 mixing bands, preferably 4 bands, on the screw.
Further, in order to prevent blackening of the screw and prevention of contamination, it is necessary to set the screw diameter to groove pitch ratio to 100 to 30 to 60 and fill the resin into the screw groove to “prevent burning”. Single screw extruders are much easier to clean and reassemble dirty screws than twin screw extruders.

Next, the present invention will be described in detail based on examples. First, the evaluation method is as follows.
(1) Intrinsic Viscosity: For PET and PET-based polyester, an equal weight mixed solvent of 1,1,2,2-tetrachloroethane and phenol was used and measured at 25 ° C. with a Canon Fünsch viscometer.
(2) MFR: According to the condition 20 of JIS K7210, PET and PET-based polyester were measured under the conditions of a temperature of 280 ° C. and a load of 2.16 kg.
(3) Swell: Using a melt indexer for MFR, swelled under conditions of a temperature of 280 ° C. and a load of 2.16 kg, cut the sample when it dropped 2.0 cm, and measured the diameter at 5.0 mm from the lower end. It was calculated by the following formula.
Swell (%) = [(average diameter−2.095) /2.095] × 100
(4) Molecular weight: The PET polyester was measured by the GPC method under the following conditions.
(Main body) Showa Denko System-21, (Column) Shodex KF-606M (2) Sample, both reference side (Solvent) Hexafluoroisopropyl alcohol, (Column temperature) 40 ° C, (Injection volume) 20 µl, Flow rate : 0.6 ml / min, (polymer concentration) 0.15% by weight, (detector) Shodex RI-74, (molecular weight conversion standard) PMMA: Shodex M-75
(5) Measurement of DSC: DSC220 manufactured by Seiko Denshi was used, and measurement was performed at a sample of 5-15 mg, nitrogen of 50 ml / min, a heating rate of 10 ° C./min, and 20-300 ° C.
(6) Measurement of mechanical properties: The film of the present invention was subjected to a tensile test according to JIS K7113 using Tensilon at a tensile speed of 50 to 500 mm / min.
(7) Melt viscosity: Measured by applying torsional vibration between hot plates at 280 ° C. in a nitrogen atmosphere using a DynAlyser DAR-100 manufactured by REOLOGICA, Sweden, under a nitrogen atmosphere at 280 ° C.

[Production Examples 1-2: binder master batches d1-d2]
Production Example 1: Berstorf twin screw extruder, caliber 43 mm, L / D = 43, 3-stage oil-sealed vacuum puller, clear bottle flakes from Yoshino PET Bottle Recycle Co., Ltd. 0.73 dl / g, MFR 40.4 g / 10 min, swell-10%) was dried with hot air at 120 ° C. for about 12 hours, 100 parts by weight were set at a temperature of 260 to 270 ° C., a screw speed of 150 rpm, and a first vent of about While extruding at -600 mmHg, a third vent of about -670 mmHg, and an automatic resin feed rate of 35 kg / h, a bifunctional epoxy compound (abbreviated as D) as a binder from the second vent hole is an ethylene glycol diglycidyl ether (Kyoeisha Chemical ( Epolite 40E, epoxy equivalent 135g / eq, light yellow liquid) 15 parts by weight was injected and mixed with a metering pump. . Five strands flowing out from a die hole diameter of 3.5 mm were cooled with water and cut into pellets by a rotary cutter. 100 kg of each of the obtained hot pellets was dried with hot air at 40 ° C. for about 0.5 hours and stored in a moisture-proof bag (paper / aluminum / polyethylene three layers) (binder master batch d1: bifunctional / 3 functional ratio) T / D = 0/100, effective binder 0.130 wt.%).

  Production Example 2: Similarly, trifunctional trimethylolpropane triglycidyl ether (abbreviated as T, Epolite 100MF of Kyoeisha Chemical Co., Ltd., epoxy equivalent 150 g / eq, 50 parts by weight of ethylene glycol diglycidyl ether (Yellow liquid) 50 parts by weight of a mixture of 15 parts by weight was injected with a metering pump. Five strands flowing out from a die hole diameter of 3.5 mm were cooled with water and cut into pellets by a rotary cutter. Similarly, it was dried with hot air and stored in a moisture-proof bag (paper / aluminum / polyethylene three layers) (binder master batch d2: T / D = 50/50, effective binder 0.130 wt.%).

[Production Example 3: Catalyst master batch f1]
50 parts by weight of calcium stearate as a base material for the lubricant and masterbatch was added to 25 parts by weight of lithium stearate as a powdered catalyst and 25 parts by weight of sodium stearate. These powdery composite catalysts were mixed with a tumbler until uniform (powdered composite catalyst master batch f1: Li / Na / Ca = 25/25/50).

[Granulation example of high molecular weight, high melt tension PET resin P1 by a twin screw extruder]
Clear Flakes from Yono PET Bottle Recycle Co., Ltd. (PET bottle recovered product, PET 99.9%, intrinsic viscosity 0.72 dl / g, MFR 57 g / 10 min, swell -10%, molecular weight Mn 11,500, Mw 27,800, 100 parts by weight of a hot-air dried product (water content 150 ppm) having a MW / Mn = 2.4, a zero share at 280 ° C. and a viscosity of 700 poise, a bifunctional (D) ethylene glycol diglycidyl ether master batch d1 (Production Example 1; T / D ratio = 0/100): masterbatch d2 containing 4 parts by weight (effective amount of binder: 0.52 parts by weight) and trifunctional (T) trimethylolpropane / triglycidylate (Production Example 2; T / D) Ratio = 50/50): 4 parts by weight (effective amount 0.52 parts by weight), white powdery composite catalyst master batch f1 (Production Example 3: Li / N) a / Ca = 25/25/50) 0.15 part by weight was mixed with a tumbler mixer for 5 minutes. Ikekai's twin screw extruder PCM-70, caliber 70 mm, L / D = 37, using a 3-vent oil-sealed vacuum line, set temperature 270-280 ° C., screw rotation speed 100 rpm, about 1st vent The reaction was carried out by dehydration, deaeration and mixing while extruding at 0.096 MPa, the second and third vents at about 0.098 MPa, and an automatic feed rate of 50 kg / h.
At first, when a die having a hole diameter of 6 mm × 5 nozzles was used, two strands at both ends became unstable, became unstable due to curling or surging, and sometimes cut and dropped. When sealed with a brass pin, the two ends of the three strands were similarly unstable again, curling again, and occasionally cut and dropped.
Next, when the die was replaced with a 2 mm × 10 nozzle die, the granulation operation was stabilized. The strand was extruded into water and cut into pellets with a rotary cutter. The obtained pellets were dried with hot air at 140 ° C. for about 3.5 hours and stored in a moisture-proof bag. The high molecular weight and high melt tension PET pellet P1 of the present invention using a recovered PET bottle as a raw material is yellowish white, MFR average 2.6 g / 10 min (IV value 0.99), swell 140%, zero share of 280 ° C.− The viscosity was 120,000 poise and the yield was about 300 kg.

Examples 2-3

[Granulation example of high molecular weight, high melt tension resins P2 to P3 by single screw extruder]
Example 2: Deodorized air-dried product (moisture 50 ppm) of clear flake from Yono PET Bottle Recycle Co., Ltd. (collected PET bottle, intrinsic viscosity 0.74 dl / g, MFR 40 g / 10 min, swell -10%) 100 Master batch d2 containing parts by weight, bifunctional (D) ethylene glycol diglycidyl ether and trifunctional (T) trimethylolpropane triglycidyl ether (Production Example 2; T / D ratio = 50/50): 5 0.5 part by weight (effective amount 0.715 part by weight), powdered composite catalyst master batch f1 (Production Example 3: Li / Na / Ca = 25/25/50) 0.20 part by weight, stabilizer Irganox B225: 0.1 parts by weight, liquid paraffin: 0.05 parts by weight were mixed with a super mixer for 2 minutes.
Using a single-screw extruder (star diameter: 100 mm, Bitch ratio 43 compression type screw, L / D18 = 32), Hoshi Plastics Co., Ltd., screw rotation speed 20 rpm, raw material mixture feed rate 40 kg / h, cylinder center 1 Reaction extrusion was started at a vent type and a cylinder set temperature of 240 to 320 ° C. The die was protruded obliquely downward at an inner diameter of 3.5 mm, a wall thickness of 0.5 mm, a protruding length of 7 mm, and a die at an interval of 10 mm to prevent strands from sticking together. The nozzle was screwed into the die.
The strand was cooled with water and cut with a rotary fan cutter to form cylindrical mini-pellets. The obtained colorless and transparent pellets were dried with hot air at 140 ° C. for about 3.5 hours and stored in a moisture-proof bag. The high melt tension pet P2 of the present invention using a recovered PET bottle as a raw material has an MFR change with time of 5.4 g / 10 minutes (after 1 hour), 8.4 g / 10 minutes (after 2 hours), 11.5 g / It was 10 minutes (after 3 hours), and clearly “an increase in MFR”.

  Example 2 Next, a 1-inch diameter copper conduit was installed from the screw under the hopper through the hopper to the top of the hopper, and the granulation operation was performed in the same manner as described above. The obtained high melt tension pet P3 has an MFR change with time of 5.5 g / 10 minutes (after 1 hour), 6.1 g / 10 minutes (after 2 hours), 5.3 g / 10 minutes (after 3 hours). Clearly stable over the long term. The pellets after 3 hours of the high molecular weight and high melt tension PET pellets P3 of the present invention were white after drying, had a swell of 55%, a zero share of 280 ° C. and a viscosity of 180,000 poise, and the yield was about 40 kg.

The high melt tension polyethylene terephthalate-based polyester granulated pellets of the present invention enable new molded products such as foams, tubular method films, direct blow method bottles and pipes, which are difficult to be molded by conventional PET resins. Therefore, it is useful in fields such as packaging materials, daily necessities such as industrial materials, civil engineering architecture, electronic electrical machinery, and automobile interior materials.
In addition, since a large amount of collected PET bottles generated in large quantities can be used effectively as a raw material, it is extremely beneficial to society. Furthermore, even if incineration is performed after use, the calorific value of combustion is low compared to polyethylene and polypropylene, and the incinerator is less likely to be damaged, and no toxic gas is generated.

Claims (4)

Component A: 100 parts by weight of polyethylene terephthalate polyester
Component B: Mixture in which the weight ratio of compound a containing 2 epoxy groups in the molecule to compound b containing 3 or more epoxy groups in the molecule as a binder is 95-40 to 5-60 0.1 ~ 2 parts by weight,
Component C: A raw material mixture D composed of 0.05 to 1 part by weight of a metal salt of an organic acid as a catalyst is melted at a temperature equal to or higher than its melting point and uniformly reacted by reactive extrusion while degassing and dehydrating under vacuum. By high-strength polyethylene terephthalate polyester having a melt flow rate of 20 g / min or less and a swell of 1 to 200% according to JIS method (280 ° C., load 2.16 Kg), pelletized stably for a long time under specific conditions. A continuous granulator characterized by.   A high melt tension polyethylene terephthalate polyester is stably pelletized for a long period of time by installing a conduit for releasing water vapor into the atmosphere in a hopper that supplies a raw material mixture D to a screw of a reaction extruder. Item 2. The continuous granulator according to Item 1.   The high melt tension polyethylene terephthalate-based polyester is pelletized stably for a long period of time by installing a nozzle having an inner diameter of 1 to 5 mm and a protrusion length of 0.5 to 10 mm in a die of a reaction extruder. 2. The continuous granulator according to 2.   A high-melting-strength polyethylene terephthalate-based polyester is stably pelletized over a long period of time by using a caliber / groove pitch ratio of 100 / 30-60 and a mixing zone of 2-4 as a single screw of a reaction extruder. The continuous granulation apparatus according to any one of claims 1 to 3.