JP3103042B2 - Antimicrobial PET resin master pellet and its composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial PET resin master pellet for producing an antibacterial PET product from a regular polyethylene terephthalate (PET) resin raw material.

[0002]

2. Description of the Related Art Conventionally, in order to mix an additive such as titanium oxide with PET, a master batch or a master pellet containing a high concentration of an additive is first manufactured in a first step, and a raw material is prepared in a second step. In general, a master pellet was added to PET so that the above additive had a predetermined concentration, followed by mixing and integration. However, when silver zeolite is used as an additive in order to produce an antimicrobial PET resin composition, when an attempt is made to produce master pellets using silver zeolite, the additive is used due to uneven dispersion of silver zeolite. It was impossible to achieve the original purpose of master pellets of uniform mixing. In order to solve this, a so-called "side injection method" has been proposed in which silver zeolite is dispersed in a polyol solvent in advance, and the molten slurry is mixed with a PET melt by an extruder and molded by an extruder. However, in this method, uniform mixing is more difficult than in the case of using general master pellets, resulting in uneven quality of the product, and a product having a high product value cannot be obtained. In addition, the extruder used in the manufacture of various products also requires a special structure to inject the molten slurry from the side of the equipment, resulting in expensive equipment and lack of versatility of the equipment. And it was hard to switch products.

[0003]

A master pellet of PET containing about 10 to 30% by weight of an additive is generally prepared by mixing an additive with a PET resin, melting it by heating, and then melting the PET into a udon shape from a discharge mouthpiece. And continuously cooling with water. This is because if water cooling is not performed after the melt-discharge, the melts of the PET resin discharged in a udon shape are fused to each other and uniform pellets cannot be obtained. When silver zeolite is used as an additive for the master pellets, the water used for water cooling causes the silver zeolites to bind tightly to the silver zeolite crystals like water of crystallization, and even if the obtained master pellet is dried, the water of crystallization remains Without being removed, the water of crystallization of silver zeolite is released for the first time until the master pellet is mixed with the Regillar PET pellet and melted and discharged at 290 to 300 ° C. by an extruder. Under the influence of the released water, depolymerization of PET occurs, resulting in a decrease in physical properties. For example, when spinning PET fibers, there is a disadvantage that the yarn is cut and spinning becomes difficult. In addition, when a PET resin film or molded product is formed, there is a problem that after extrusion, the film becomes cloudy and loses a sense of transparency, and the thickness also varies to make a non-defective product. In view of the above reasons, by completing PET resin master pellets of silver zeolite suitable for uniform mixing, it becomes possible to perform uniform mixing far more than the slurry method without using expensive equipment, and it is a versatile, simple and useful technology. The development of was craving.

[0004]

In the conventional PET pellets, the molten PET resin melted at 290 to 300.degree. C. is cut into pellets, though the temperature is lowered when discharged from a die of an extruder. At a certain point, the temperature for fusing with each other is still maintained, so that a water cooling step was absolutely necessary as described above. The present invention is a technique that does not require a water-cooling step during production in a silver zeolite-containing PET resin master pellet as described above, and the silver zeolite-containing PET resin master pellet obtained in the present invention is a silver-containing zeolite-containing PET resin master pellet. Since the zeolite does not generate water of crystallization at all, the production of the PET resin composition mixed with the PET resin master pellets does not cause any trouble as in the prior art, and the fibers and moldings produced from this composition do not occur. There is no abnormality in product quality. That is, in the present invention, in obtaining a PET resin master pellet containing 10 to 30% by weight of silver zeolite, a low melting point PET resin was used, and the contained water was adjusted, whereby the PET resin was mixed into the regular PET resin. At this time, it was found that a molded product in which fusion of the discharged products did not occur without a water cooling operation after the discharge was obtained.

[0005] In the present invention, a water content of 400 ppm could be obtained by producing PET resin pellets without cooling with water using a PET resin having a low melting point of 150 to 230 ° C. In the case of a PET resin having a melting point of 230 ° C. or higher, a candy-like mass is formed without water cooling after discharge, and pellets cannot be cut. In the case of pellets having a melting point of 150 ° C. or less, not only is the melting point too low, causing cut abnormalities, but also if mixed with regular PET, the melting point of the mixed PET decreases and loses the original moldability of regular PET resin. In the present invention, a low melting point PET resin having a temperature of 150 ° C. or lower is not suitable for use. PET resin usually has a melting point of 25.
The temperature is generally about 0 to 265 ° C, but in the present invention, a material having a melting point of about 150 to 230 ° C, which is much lower than a general melting point, is used. By setting the amount to 400 ppm or less, it becomes possible to obtain a PET product which is free from fusion of the ejected materials when it is mixed with regular PET without a water cooling operation after ejection.

By using the PET resin master pellet obtained in the present invention in combination with the chitosan salt of the reaction product of chitosan and adipic acid, the moldability of the PET resin composition can be further enhanced. The silver zeolite used in the present invention is not particularly limited, and a general-purpose silver zeolite can be used. However, it is preferable that the zeolite is calcined at a temperature of about 400 ° C. to make it anhydrous. In the present invention, the master batch is cut at the melt discharge port from the extruder, and is exposed to the atmosphere for a short time until the packaging of the pellets as master pellets.
The water content of the master pellet of the present invention is 400 ppm
Since it can be managed as follows, it is mixed with Regular PET resin to produce molded products such as fibers, films, containers, etc., and there is no abnormality, loss of transparency, irregular thickness, no deterioration in physical properties, etc. . In the present invention, the master pellets of silver zeolite can be similarly used for compounds conventionally used in the slurry method, such as, for example, a cationic antistatic agent, chitosan, and chitosan salt.

[0007]

Example 1 30 parts by weight of a low melting point PET resin having a melting point of 220 ° C. “RN-165” (trade name: manufactured by Nippon Unipet Co., Ltd.) were mixed with 30% by weight of “AK” as an anhydrous silver zeolite.
-80H "(trade name: Shinagawa Fuel Co., Ltd.), 10 parts by weight, and 0.5 part of zinc stearate as a dispersant were mixed and melted at 235 ° C., and extruded in an extruder into a 2 mmφ udon shape. The pellets were cut to 2 mm in length without water cooling to prepare PET resin master pellets for antibacterial use.93 parts by weight of regular PET resin were mixed with 7 parts of the above-mentioned master pellets for antimicrobial PET resin, and extruded.
At 40 denier after melt mixing at 90 ° C., 20 filament long fibers could be produced without any abnormality. A half dough was knitted by a tricot using the long fibers, and a refining finish was performed. About the above tricot dough,
As a result of inoculating Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and MRSA in accordance with the SEK count method, no bacteria were measured even after 12 hours. The obtained tricot dough has an excellent antibacterial effect, and can be sufficiently used for hospital use as a countermeasure for nosocomial infection.

[0008]

Example 2 45 parts by weight of a low melting point polyester resin having a melting point of 190 ° C., 15 parts by weight of anhydrous silver zeolite AK-80H (product name: Shinagawa Fuel Co., Ltd.), and a chitosan salt obtained by reacting chitosan with adipic acid Was melted at 190 ° C., discharged in a 2 mmφ udon shape by an extruder, and cut into 2 mm without water cooling to produce an antimicrobial PET resin master pellet. Regular P
Antibacterial PET used in Example 1 was added to 95 parts by weight of ET resin.
Five parts by weight of the resin master pellets were mixed, melted and mixed at 290 ° C. by an extruder, extruded from a T-die, and rapidly cooled to obtain a non-stretched sheet having a thickness of 200 μm.
The obtained sheet was transparent without devitrification and had a uniform thickness. Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were inoculated according to the SEK bacterial count test method, but no bacteria were detected even after 12 hours, and it was confirmed that a sheet with excellent antibacterial effect was obtained. did it.

[0009]

Example 3 40 parts by weight of a low-melting polyester resin having a melting point of 160 ° C. and 10 parts by weight of anhydrous silver zeolite AK-80H (trade name: product of Shinagawa Fuel Co., Ltd.) were mixed and mixed.
Melt at 0 ° C, discharge into a 2mmφ udon shape with an extruder, cut to 2mm without water cooling and PET for antibacterial
Manure master pellets were produced. 95 parts by weight of the regular PET resin was mixed with 5 parts by weight of the antibacterial PET resin master pellet used in Example 1 to prepare a preform by using an injection molding machine, and cooled to room temperature. The obtained preform was heated, and 0.5 mm with a biaxial stretch blow molding machine.
Was manufactured. The bottle after molding was transparent without devitrification. The obtained bottle was inoculated with Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa in accordance with the SEK bacteria count test method. As a result, no bacteria were measured after 12 hours, and the bottle was excellent in antibacterial effect. all right. The obtained bottle was excellent as an antibacterial effect, and thus was useful as a bottle for storing water.

[0010]

According to the present invention, a silver zeolite master pellet having a high uniform dispersibility can be obtained.
It can be easily mixed with ET, can be mixed far more uniformly than the slurry method without using expensive molding equipment, and the added value of the obtained PET product is high.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Koji Nakamura Inventor 6-41, Nishi-Awaji, Higashi-Yodogawa-ku, Osaka-shi, Osaka Inside the Awaji Plant of Nakamura Bussan Co., Ltd. (56) References JP-A-62-195037 (JP, A (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 3/22 C08L 67/00-67/02

Claims (3)

(57) [Claims] 1. A low melting point polyethylene terephthalate resin having a melting point of 150.degree. C. to 230.degree. C. containing 10 to 30% by weight of silver zeolite as a raw material.
An antibacterial polyethylene phthalate resin master pellet having a water content of 400 ppm or less, characterized by being formed into pellets without being used. 2. A polyethylene terephthalate resin composition having a melting point of 250 to 265 ° C., comprising the master pellet of claim 1. 3. A polyethylene having a low melting point of 150 ° C. to 230 ° C.
10-30 weight of silver zeolite in terephthalate resin
% After melting and discharging, without cooling with water.
The moisture content obtained by
Antibacterial polyethylene terephthalate resin master paper below
Lett is a regular polyethylene having a melting point of 250 to 265 ° C.
Characterized in that it is blended with lentephthalate resin.
A method for producing a polyethylene terephthalate resin molded product.