JPS58203106A - Melt extrusion of synthetic resin - Google Patents

Abstract

PURPOSE:When a synthetic resin is melt extruded using a screw extruder, a small amount of a different kind of resin is fed from the opening, as extrusion is effected, to give heterogeneous monofilaments of firm adhesion with good color and touch. CONSTITUTION:A synthetic resin is fed from hopper 2 to the screw extruder 1 where the resin is plasticized and sent to the die 6. In the meantime, a small amount of a different kind of synthetic resin is fed from the opening 4 on the latter half of the cylinder using another extruder equipped with a nozzle 5 and the two polymer-containing melt is extruded through many nozzles on the die 6 into strings. The extruded strings 7 are cooled in the cooling bath 8, drawn between the first rolls 9, the drawing tank 10 and the second rolls 11, heat treated with the device 12, taken up with the third roller 13 and wound up with the winder 15.

Description

[Detailed description of the invention] The present invention relates to a melt extrusion method for a developed synthetic resin.

Monofilaments of synthetic resins such as nylon and polypropylene are used in robes, fishing nets, and industrial textiles.

Manufactured in large quantities as industrial materials such as furniture textiles.

It's on sale. In this melt extrusion method, the monofilament is generally produced by a melt extrusion method using a screw extruder.

A molten raw synthetic resin plasticized by an extruder is melt-extruded from a nozzle of a die, and a single synthetic resin is usually used as the raw synthetic resin.

For this reason, monofilaments produced by conventional melt extrusion methods (although they were satisfactory for applications requiring physical properties such as tensile strength), on the other hand, they lacked the color and texture of natural materials. However, when olefin synthetic resins such as polypropylene and polyethylene are used as raw material synthetic resins, they have the disadvantage of poor adhesion to other types of substrates unless a suitable adhesive is available. .

Therefore, in order to improve the above-mentioned melt extrusion method.

Two types of synthetic resins with different chemical properties or colors are
A method of uniformly blending using a shaft extruder and melt-extruding the molten bullet, and a method of supplying two types of synthetic resin separately and combining them at the tip of a die nozzle and melt-extruding were proposed. .

However, in the first method, two types of synthetic resins are mixed uniformly and then melt-extruded, resulting in a monofilan/1.
The color and texture are the same as those obtained by conventional methods. Unfortunately, in the second method, the bonding between the two types of synthetic resins is not sufficient, and filaments of each synthetic resin tend to separate during the drawing process when forming monofilaments using the usual method.

Moreover, it is difficult to use the nozzle continuously for a long period of time, and it is difficult to melt extrude using a commonly used die equipped with a large number of nozzles (i.e., to take a large number of them), and the productivity of monofilament is extremely low. It has the following drawbacks.

Therefore, depending on conventionally known methods, different types of synthetic resins are melt-extruded to achieve excellent color and texture.

Alternatively, it has not been possible to produce monofilaments with good productivity that have both the physical properties of monofilaments of olefinic synthetic resins and the adhesive properties of polar synthetic resins.

The inventors completed this invention as a result of intensive research aimed at improving the drawbacks of the conventionally known melt extrusion method.

That is, in the present invention, when a synthetic resin (A) is melt-extruded using a screw extruder, a synthetic resin (B ) is continuously fed into an extruder in small quantities, and a melt consisting of synthetic resin (A) and synthetic resin (B) is extruded in the form of a string from multiple nozzles of a die. It is related to.

With the method of this invention, a flat and heterogeneous monofilament with a single color or texture can be produced with a simple operation.

Alternatively, a heterogeneous monofilament in which a non-polar synthetic resin such as an olefin synthetic resin and a polar synthetic resin such as nylon are firmly bonded can be continuously produced.

In the method of the present invention, a synthetic resin (A), which is a main component, and a small amount of a synthetic resin (B), which is different from the two synthetic resins, are used as raw material synthetic resins.

In the description of this specification, "synthetic resin (B) different from synthetic resin (A)" refers to the chemical properties of synthetic resin (B) (
It means that the color (i.e., the color tone of the pigment blended in the synthetic resin (B)) is different from that of the synthetic resin (A).

As the synthetic resin (A) or synthetic resin (B),

Polypropylene, polyethylene, polystyrene.

Examples include polyvinyl chloride, vinylidene chloride-vinyl chloride copolymer, nylon, polyester, etc. 4. The polypropylene mentioned above has an isotactic structure of 11 parts, and has a high melt flow rate (MFR). The size is about 0.5 to 0.7ft'710 minutes.
Preferably, it contains a stabilizer against heat and light. Polyethylene manufactured by medium-low pressure method is mainly used.

It is preferable that the melt intex is about 0.4 to 0.9, and it is preferable that a stabilizer against heat and light is added to the raw material pellets. The polystyrene preferably has a high degree of polymerization. Polyvinyl chloride has a polymerization degree of 1000 to 200
A value of about 00 is preferable.

A heat stabilizer is used. Vinylidene chloride-vinyl chloride copolymer is vinylitine chloride 80-9
It is preferable that a copolymer of 0 weight percent and 20 to 10 weight percent of vinyl chloride is used, and additives such as a plasticizer and a heat stabilizer are blended therein. Nylon is nylon 6, nylon 6
6. Nylon 610, Nylon 11. Nylon 12. Any nylon 612 may be used. The synthetic resin may contain pigments, blowing agents, flame retardants, antistatic agents, and the like.

If the chemical properties of the synthetic resin (A) and the synthetic resin (B) are the same or similar, the synthetic resin (A) and the synthetic resin (B) should each have different colors (
In other words, it is necessary to use pigments with different tones), and when the chemical properties of the two synthetic resins (A) and the synthetic resins (B) are completely different, the two synthetic resins (A) and synthetic resins (B) are
) may be different colors or may be the same color.

The blending ratio of synthetic resin (A) and synthetic resin 3 (B) is 5. Synthetic resin (B) is 0.1 to 10 parts by weight per 100 parts by weight of the total amount of synthetic resin (A) and synthetic resin (B). parts by weight, especially 1
A ratio of ˜2 parts by weight is preferred.

In the method of the present invention, a synthetic resin (A) arbitrarily selected from the various synthetic resins described above, preferably an olefinic synthetic resin such as polypropylene, is added to the synthetic resin (A) by a method known per se. The pellets in A) are fed to the screw extruder by the method of feeding them into the hopper, plasticized by the screw, and sent to the die installed at the head of the extruder.The set temperature of each part of the screw extruder is used. 2, preferably at least about 5°C higher than the melting point of the synthetic resin (A);
) is below the decomposition temperature of

In the method of this invention, the synthetic resin (A) is plasticized as described above and sent to the die, and at the same time, the second half of the cylinder of the extruder (that is, the second half of the cylinder containing the extruder screw/the second half of the cylinder) .

Synthesis is carried out preferably through an opening provided at the tip of the extruder cylinder (i.e., the tip of the cylinder containing the extruder scree), preferably by an extruder with a nozzle connected to the opening. A small amount of the synthetic resin CB), which is different from the resin (A), is continuously fed into the extruder, and the melt consisting of the synthetic resin (A) and the synthetic resin (B) is passed through a large number of dies, preferably 1 to 200 dies. It is extruded in the form of a string from a nozzle.

In the method of this invention, an opening [
]It is necessary to continuously feed a small amount of synthetic resin (B) into the extruder from the section 2, and extrude the molten material consisting of synthetic resin (A) and synthetic resin (B) in the form of a string from multiple nozzles of the die. Thus, it is possible to obtain a heterogeneous monofilament in which the synthetic resin (A) and the synthetic resin (B) are firmly bonded. Synthetic resin (A) in the hopper of the extruder
At the same time, synthetic resin (B) is supplied and these are screened.
Even if a molten mixture of synthetic resin (A) and synthetic resin (B) that has been plasticized and uniformly kneaded is extruded into a string shape from multiple nozzles of a die, there will be no difference between the synthetic resin (A) and synthetic resin (B). It is not possible to produce homogeneous monofilaments.

The shape of the nozzle of the die used in the method of this invention may be circular, irregular, or shaped. There are many in the die,
Preferably 20 to 200 nozzles are provided.

The ratio of nozzle hole to land: L/D is preferably 1 to 20. The diameter of the nozzle hole is selected depending on the intended fineness of the monofilament, and is usually 0.1 to 5. The set temperature of the die is at least the melting point of the synthetic resin (B) to be used and at least 1 degree higher than the melting point of the synthetic resin (B), preferably at least 5"'c +" degrees higher than these melting points.

By the method of this invention, synthetic resin (A) and synthetic resin (1
3) Heterogeneous monofilament firmly bonded with /1.
The reason for this is not clear, but the molten synthetic resin (A) sent to the die by the screw and the molten resin (A) supplied from the opening in the rear half of the extruder cylinder. The synthetic resin (B) in the state is scratched...
By being partially kneaded by °.

Synthetic resin (B) with synthetic resin (B) diffused on the surface of the molten synthetic resin (A) and synthetic resin (B)
When the general melt consisting of is subdivided through multiple nozzles of the die and pressed into strings (71), a part of the synthetic resin (B) is incorporated into the string-like extrudate of the synthetic resin (A), Next, the string-like extrudate made of synthetic resin (A) and synthetic resin (B) is cooled by a method known per se, and the synthetic resin (A) and synthetic resin (B) are firmly bonded by a kind of anchoring effect. It is presumed that this is because the

The monofilament obtained by the method of this invention is
The synthetic resin (B) is non-uniformly bonded to the synthetic resin (A) string-like material, which is the main part, so that there is no chance of the synthetic resin filaments separating into filaments during the drawing process using a normal method.

Hereinafter, the present invention will be further explained using FIG. 1, which shows an example of manufacturing a monofilament by the method of the present invention.

In FIG. 1, a synthetic resin (A) is supplied from a screw extruder 10 and a hopper 2, and this synthetic resin (A) is plasticized by the screw and sent to a die 6 provided at the head of the extruder. . On the other hand, the extruder's 7 cylinders - Ω
From the opening 1-1 part 4 provided in the rear ten part.

An extruder 5 with a nozzle connected to the opening continuously supplies a small amount of a synthetic resin (13) different from the synthetic resin (A) into the extruder from the nozzle, and the 2 synthetic resins (A) and the synthetic resin are The molten material consisting of (B) is extruded in the form of a string from multiple nozzles of die B. This string-like extrudate 7 is cooled in a cooling tank 8 to preferably a temperature of 100°C or less.

No. 10 - Rule 9 and stretching tank 10 (usually filled with boiling water)
and the 20th roll 11, preferably about 2 to 6 times, and if necessary, subjected to heat treatment in the heat treatment device 12 (usually a hot air heating type), and then stretched to the sixth roll 13.
The monofilament is taken off at a take-up speed of about 10-2 D Om/min. ).

The monofilaments 14 that have passed through the 60th loop 13 are separated by a guide bar and wound one by one onto separate bobbins by a nine winding device 15.

The monofilament obtained by the method of this invention is
Ropes, fishing nets, industrial textiles, furniture textiles.

It can be used as a material for slippers, sheath fabrics, hats, bags, etc.

Examples and comparative examples are shown below.

On each side of the following, the heat treatment equipment 12 of FIG.
Monofilament was produced using the apparatus except for No. 60 and No. 60.

In the hopper of an extruder with a cylinder inner diameter of 50TIrmρ and an L/D of 24 (cylinder tip temperature set at 230°C),
Polypropylene pellets (manufactured by Ube Industries, Ltd.) containing a phenolic stabilizer were supplied. on the other hand.

An extruder with a nozzle connected to the opening provided at the tip of the cylinder (cylinder inner diameter 25 mm l, L/D
24. Nylon 6 pellets (manufactured by Ube Industries, Ltd.) containing a brown pigment were supplied from a nozzle with a temperature set at the tip of the linder (temperature set at 260°C). The ratio of polypropylene and nylon 6 sent to the die is 2 parts by weight of nylon 6 to 98 parts by weight of polypropylene. The molten material consisting of polypropylene and nylon 6 sent to the die was passed through 020 nozzles of the die (the hole shape was circular, the inner diameter was 1 m/L/
D was extruded from 4) into a string shape. This string-like extrudate was cooled with cooling water, stretched five times with a roll, a boiling water tank, and a roll at a take-up speed of 70 m/min, and wound up on a bobbin.

In the obtained monofilament, ocher-colored nylon 6 was unevenly bonded to one side of the polypropylene string. This monofilament, which was composed of two layers, a polypropylene layer and a nylon 60 layer, had a good color and texture, and had a good color and texture. Furthermore, the tensile strength of this monofilament was comparable to or higher than that of monofilament made of polypropylene.

Example 2 The procedure was the same as in Example 1 except that polypropylene pellets containing a stabilizer and a blowing agent were fed from the hopper of the extruder.9 Ocher color was formed on one side of a polypropylene string with an expansion ratio of about 6 times. A monofilament consisting of two layers of nylon 6 was obtained.

This monofilament has a smooth surface.9
It has a good color and texture.

The tensile strength was also at a level suitable for practical use.

Comparative Example 1 Polypropylene pellets mixed with a stabilizer and nylon 6 pellets were simultaneously fed into a hopper at a weight ratio of 98:2, the polypropylene and nylon 6 were plasticized, and the molten mixture was transferred to a die. A monofilament was produced in the same manner as in Example 1 except that it was extruded from a nozzle.

The obtained monofilament did not form two layers of polypropylene and nylon 6, was pale yellow, had two colors, and did not have a good texture.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of manufacturing a monofilament by the method of the present invention. 1 extruder, 2: Hozuno-no-25 Niji cylinder-24: Open [1 part, 5: Extruder with nozzle. 6: Die, 7: String extrudate, 8: Cooling tank, 9: 10th-
Rule, 10; Stretching tank, 11: Rule 20. 12: Heat treatment equipment, 13: Roller, 14: Monofilament, 15: Winding device Patent applicant: Ube Industries, Ltd. Patent applicant: Fukushima Kogyo Co., Ltd.

Claims (1)

[Claims] For melt extruding synthetic resin (A) using a screw extruder. Push a small amount of synthetic resin (A) and a different type of synthetic resin (B) from the opening [ ] provided in the rear part of the extruder / ring.
Two synthetic resins (A) and two synthetic resins (B) are continuously supplied into the machine.
) is extruded in the form of a string from multiple nozzles of a die.