JPS5818396B2 - Seiden Seifu Yosareta Gouseijiyugoutaiseikeibutuno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a synthetic polymer molded article imparted with antistatic properties.

Synthetic polymers represented by polyamides and polyesters have excellent abrasion resistance, strength and elongation, and therefore have great industrial value as fibers, films, and other plastic materials.

However, synthetic polymers have the disadvantage that they have little antistatic property (and are easy to generate static electricity due to friction).

Conventionally, as a method of obtaining molded synthetic polymers with excellent antistatic properties, a method has been known in which a synthetic polymer is mixed with fine powder of a conductive substance (for example, fine metal powder) and then melt-molded. There is.

However, in order to obtain a melt molded product with sufficient antistatic properties, the above-mentioned mixing must be carried out so that the fine powder is contained in the synthetic polymer molded product in an amount of 10% by weight or more, preferably 20% by weight or more. However, in such a case, there is a drawback that it is difficult to perform melt molding in a good manner (for example, yarn breakage occurs frequently during melt spinning).

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for producing a molded synthetic polymer having excellent antistatic properties without the above-mentioned drawbacks during melt molding.

The present invention, which has achieved this object, uses a synthetic polymer;
Synthetic polymer (B) containing 10 to 90% by weight of conductive fine powder and incompatible with the synthetic polymer pores,
This is a method for producing a synthetic polymer molded product having antistatic properties, which is characterized by mixing at a ratio of 9:1 to 3:1 (weight ratio) and melt-molding.

In the present invention, a synthetic polymer refers to a synthetic polymer that can be melt-molded.

Examples of such synthetic polymers include polycaproamide, polyhexamethylene adipamide and copolyamides based on these, polyethylene terephthalate, polyethylene naphthalate and copolyesters based on these, polyethylene, polycarbonate, polystyrene, etc. There is.

The synthetic polymer may also contain small amounts of additives such as matting agents, heat stabilizers, etc.

In the present invention, "synthetic polymer (B) that is incompatible with synthetic polymer holes" refers to the synthetic polymer (B) that is mixed with synthetic polymer (5) and melt-molded. Means to be chemically inert to coalescent holes.

In addition, when synthetic polymer (5) and synthetic polymer (B) are not compatible with each other, when they are mixed and melt-molded,
Depending on the mixing ratio, a molded product can be obtained in which one synthetic polymer is dispersed in the form of fibers in the other synthetic polymer.

An example of a combination of synthetic polymers (A) and (B) that are incompatible with each other is a combination of two synthetic polymers selected from polyamide, polyester, polystyrene, polyvinyl chloride, polycarbonate, etc. .

Examples of conductive fine powders that can be used in the present invention include fine powders of metals such as silver, gold, platinum, copper, brass, nickel, and aluminum, and fine powders of oxidized steel and carbon black.

When using carbon black, it is preferable to use acetylene black, which has a well-developed graphite structure.

When mixing a synthetic polymer (A) with a synthetic polymer (B) that contains 10 to 90% by weight of conductive fine powder and is not compatible with the synthetic polymer (B), both are kept in a molten state. It is possible to adopt a method in which both are mixed together, or a method in which both are formed into pellets and mixed.

Even if both are mixed uniformly in a molten state, they tend to separate into two phases within a short time after mixing, and the state of dispersion of both components in the mixture is unstable.

On the other hand, when both are formed into pellets and mixed uniformly, the state of dispersion of both components in the mixture does not change over time.

On the other hand, in the present invention, both are mixed and then melt-molded, and in industrial implementation, it usually takes a considerable amount of time after mixing until melt-molding is carried out.

Therefore, it is preferable from an industrial standpoint to adopt a method of mixing the pellets in the form of pellets, since this method has the advantage that practical molded products can be obtained more stably.

Among the synthetic polymers (B) containing conductive fine powder and incompatible with synthetic polymers, the present invention particularly focuses on synthetic polymers in which the content of conductive fine powder is 10 to 90% by weight. (
It is necessary to use B), and unless the content thereof is satisfied, the object of the present invention cannot be achieved.

This point will be specifically explained as follows.

That is, if the content of the conductive fine powder is too low, the conductivity of the synthetic polymer (former B) containing the fine powder is insufficient, and such a synthetic polymer (B) is Polymer (
Even if it is mixed with 5) and melt-molded, a molded product with sufficient antistatic properties cannot be obtained.

On the other hand, if the content of the conductive fine powder is too high, the fiber forming property of the synthetic polymer (B) containing the fine powder will be significantly reduced, and in such a synthetic polymer (B), the synthetic polymer (
When mixed with B) and melt-molded, the synthetic polymer (B) containing conductive fine powder cannot exist dispersed in the synthetic polymer (4) in the form of fibers in the resulting molded product.
Because of this, it is not possible to obtain a molded product with good antistatic properties, and it is also difficult to perform melt molding in a good manner (for example, yarn breakage occurs frequently during melt spinning). .

In the present invention, the synthetic polymer and the synthetic polymer (B) containing conductive fine powder are mixed in a ratio of 19:1 to 3:
It is also necessary to mix them at a ratio of 1:1 (by weight) and melt-form them.

□ If the mixing ratio of the synthetic polymer (B) to the synthetic polymer is too small, the antistatic properties of the molded product obtained by melt molding the mixture will be poor.

On the other hand, if the mixing ratio of the synthetic polymer (B) is too large, the synthetic polymer (B) will form a fiber in the synthetic polymer (A) in the molded product obtained by melt-molding the mixture. Since it is not dispersed and exists partially in the form of lumps, it is not possible to obtain a molded product with good antistatic properties, and it is also impossible to perform melt molding in a good manner.

On the other hand, when the synthetic polymer is mixed in the ratio specified in the present invention and melt-molded, the synthetic polymer contains one conductive fine powder and is compatible with the synthetic polymer. A molded product is obtained in which the insoluble synthetic polymer is dispersed in the form of a single fiber, and this molded product has good antistatic properties.

According to the present invention, the molded product has a good molding condition (for example, the occurrence of yarn breakage is extremely small during melt spinning).
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Figure 1 shows the steps of one embodiment of the present invention.

In this figure, 1 is a mixing tank, which contains pellets of synthetic polymer (5) and 10 to 90% by weight of conductive fine powder, and is compatible with the synthetic polymer particles. Pellets (of synthetic polymers) are each weighed and fed to a predetermined weight.

Here, the predetermined weight is a weight that satisfies a relationship such that the mixture ratio of pellets (N and pellets) (B) is 19:1 to 3:1 in the mixture of both pellets.

The two PETs uniformly mixed in the mixing tank 1 are stored in a storage tank 2, and are sent from the bottom of the tank 2 through an extruder 3 equipped with a heating device to be melted, passed through a metering pump 4, and then passed through a thread-proof mouthpiece 5. It is discharged from □ and becomes fiber Y.

FIG. 2 shows a longitudinal cross section of a fiber obtained by melt spinning according to the present invention, and from this figure, it can be seen that the synthetic polymer (B) containing conductive fine powder is present in the synthetic polymer core.
It can be seen that the particles are dispersed in the form of fibers.

The synthetic polymer molded product with good antistatic properties obtained by the present invention can be advantageously used in various fields where conventional synthetic polymer molded products are used.

When a synthetic polymer fiber with good antistatic properties is obtained according to the present invention, it may be used alone or mixed with other synthetic fibers or natural fibers by appropriate means. .

Further, the fiber i obtained according to the present invention may be used as it is, or may be subjected to various treatments, such as sublime processing, before use.

Examples of the present invention will be described in detail below.

In the examples, the quality of melt spinnability is judged as if the composition breaks once or more per hour during melt spinning.
Those with less than one yarn breakage per 0 hours are evaluated as excellent, and those in the middle are evaluated as good.

The antistatic property was measured by leaving the knitted fabric in an atmosphere of 20°C and 65% pH for 48 hours after it was completely dry, and applying a voltage of 10,000 V using a static honest meter (manufactured by Anato Shokai). Voltage and half-life were measured.

The smaller these values are, the better the antistatic property is.

The antistatic property after washing was evaluated by washing the knitted fabric for 10 minutes under the conditions of commercially available synthetic detergent 21/l, general detergent 1; 30.40°C, and then washing with water, which was repeated 10 times.

Example Using the apparatus shown in FIG. 1, a spinning material of inoculated seeds was put into a mixing tank 1 and melt-spun from a spinneret 4 to form fibers.

The obtained fiber was drawn approximately three times in accordance with a conventional method to obtain a 70 denier/16 filament fiber.

Various spinning raw materials (synthetic polymerization material and synthetic polymer (B)) placed in the mixing tank 1 are shown in Table 1.

As shown in this table, in experiments A1 to A24, synthetic polymers (
A mixture of pellets of 5) and pellets of synthetic polymer (B) containing conductive fine powder in various proportions was used as the spinning raw material, and in Experiment A25, one type of synthetic polymer was used as the spinning raw material. Using.

In the table, PET means polyethylene terephthalate.

AC is acetylene black fine powder, Ag is silver fine powder, A1 is aluminum fine powder, Cu is copper fine powder, C
uO means copper oxide fine powder, AClAg, AI, C
Both u and CuO are conductive.

Experimenter 2 to 4.7.8.11.12.15.1 in Table 1
6.18 to 23 are according to the present invention, and the other experimental plates are not according to the present invention (comparative examples).

The results of investigating the spinnability in the above experiment and the antistatic properties of the fibers obtained in the experiment are shown in the right column of Table 1.

As is clear from Table 1, the experimental sheets according to the present invention had good spinnability and antistatic properties, while those not according to the present invention (comparative examples) had poor spinnability and/or antistatic properties. It is.

To further explain the case of comparative example, experimental boiling 1 and 1
0 is because the content of conductive fine powder contained in synthetic polymer 03) is too small, and experimental samples 9 and 17 are synthetic polymers containing conductive fine powder in the mixture of synthetic polymer pellets. Since the mixing ratio of the pellets (B) was too small, the antistatic properties were insufficient.

In Experiments A5 and 13, the content of the conductive fine powder contained in the synthetic polymer (B) was too high, and in Experiments Oboro 6 and 14, the synthetic polymer (B) was present in the mixture of synthetic polymer pellets. ) The mixing ratio of pellets is too large, resulting in poor spinnability.

Experimental flat plate 24 differs from the case of the present invention in that the compatibility between the synthetic polymer diagram and (B) is good, and spinnability,
Both antistatic properties are poor.

Experimental flat plate 25 is an example in which only ordinary nylon 6 (synthetic polymer figure) is spun into fibers, and its antistatic properties are poor.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the steps of one embodiment of the present invention, and FIG.
The figure is a longitudinal cross-sectional view of a fiber obtained by spinning according to the present invention. 1... Mixing tank, 3... Extruder, 5... Spinneret.

Claims (1)

[Claims] 1 Synthetic polymer pores and synthetic polymer (B) containing 10 to 90% by weight of conductive fine powder and which is incompatible with the synthetic polymer pores in a ratio of 19:1 to 3:1 (by weight). 1. A method for producing a synthetic polymer molded product imparted with antistatic properties, characterized by mixing the mixture at a ratio of 1.0% and melt-molding the product.