JPS60224812A - Electrically conductive composite fiber - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive white composite fiber free from metal abrasion property and having excellent antistatic property, by compounding a specific electrically conductive core component with a non-conductive sheath component. CONSTITUTION:The objective composite fiber can be produced by compounding (A) an electrically conductive core component having a specific resistance of <10<7>OMEGA.cm and composed of electrically conductive particles such as tin oxide and a thermoplastic polymer such as polyethylene with (B) a non-conductive sheath component composed of a fiber-forming polymer such as nylon 6, nylon 66, etc. having a specific resistance of >=10<7>OMEGA.cm and containing 0.001-5wt% electrically conductive particles of metal oxide or metallic compound such as zinc oxide or coated with a film containing the above particles. The minimum thickness of the sheath component in the cross-section of the fiber is preferably <=3mu.

Description

[Detailed Description of the Invention] The present invention is free from metal abrasion and is free from wear! I! This invention relates to a white conductive composite HAIIIk with excellent performance.

Electrical disturbances such as electricity, discharge sickness when touching a door handle on a carpet, spark discharge due to charging of a JIk wire, or the appearance of dust in a pot are extremely troublesome.
This causes considerable discomfort. One of the effective means of imparting antistatic properties to synthetic fibers and natural fibers is conductive fibers, which are made by bonding a Hiden component made of a polymer mixed with conductive carphone black and a protective component made of a fiber-forming polymer. There is a method of mixing a small amount of composite fiber. However, since conductive composite fibers using carbon black are colored black or gray, their use is actually limited. In recent years, there has been active research into conductive fibers containing white or colorless tetragonal substances to improve the black appearance. Among them, conductive metal oxides and fine particles having a coating thereof are close to white in color and have been found to have relatively good conductivity and crosstalk properties, and are attracting attention. For example, JP-A-57-5919 and Machishima-Sho 57-11213 disclose conductive composite fibers using isoelectric metal oxides containing zinc oxide or tin oxide as raw materials. However, in order to obtain conductivity comparable to that of conductive composite fibers using conductive carbon black, it is necessary to knead 2 to 3 times as much conductive metal oxide as in the case of conductive carbon black. Some problems remain to be resolved, and practical implementation is delayed.

On the other hand, with the recent growth of the electronic equipment industry, the anti-static performance required of dust-free anti-static work clothes and carpets is becoming even more advanced than before.

Against this background, the inventors of the present invention have researched fibers that are white and exhibit high antistatic performance. Although the conductive composite fiber has excellent antistatic performance, it has remarkable metal abrasion resistance, and to improve this, a conductive core component containing particles of conductive metal oxide, etc. and a sheath component made of a fiber-forming polymer surrounding the sheath component, and the minimum thickness of the sheath component in the cross section of the m-structure is 3 μm or less! 1lJ
1[: was proposed as Japanese Patent Application No. 1t/158-214277.

As a result of further research, we found that if the sheath component also contains a small amount of conductive particles with a particle size similar to the minimum thickness of the sheath component, 1 m of gold can be produced.
The present inventors have discovered that it is possible to obtain a conductive composite fiber that is not abrasive and has control performance equivalent to that of a fiber in which the conductive component is exposed on the surface of the fiber, leading to the completion of the present invention.

That is, the present invention uses conductive particles and thermoplastic polyv-%6
&ZJt resistance is 1°・0. Less than -. From a fiber-forming polymer with a specific resistance of 1070 or higher, containing a conductive I component and 0.001 to 5 i% of particles of a conductive metal oxide or metal compound, or particles having a film thereof on the surface. It is a conductive composite fiber made by combining a non-conductive sheath component.

As the conductive particles contained in the core component, all kinds of particles can be used as long as they have a specific resistance of 100 F or less in powder form. Particles with white discolored metal oxides and metal oxide coatings, as well as metal powder (such as silver, nickel, copper, iron, or alloys thereof), copper sulfide, copper iodide, zinc sulfide, and cadmium sulfide. It is also possible to use colored materials such as metal compounds such as. Cross-sectional area of the core component i! This is because the coloring can be sufficiently hidden by reducing the ratio by l+8, for example, from 2 to 15%, or by dispersing a white pigment such as TiO2 in the sheath.

Metal oxide particles include tin oxide, zinc oxide, copper oxide,
Examples include particles such as cuprous oxide, indium oxide, zirconium oxide, and Kungesten oxide. Many metal oxides are semiconductors that are close to insulators and often do not exhibit sufficient electrical conductivity for the purpose of the present invention. However, for example, a small amount (50% of the second component) suitable for the metal oxide (impurity)
By adding 0% or more, especially 25% or more)), the conductivity can be enhanced and a material having sufficient conductivity for the purpose of the present invention can be obtained. Such conductivity reinforcement columns include:
Antimony oxide can be used for tin oxide, and metal oxides such as aluminum, potassium, indium, germanium, and tin can be used for zinc oxide.

Furthermore, titanium oxide, oxidation! lt! Particles in which a conductive film of the above-mentioned metal oxide, metal compound, or gold is formed on the surface of non-conductive inorganic particles such as lead, magnesium oxide, tin oxide, iron oxide, silicon oxide, or aluminum oxide may also be used.

The conductivity of the conductive particles is such that the specific resistance in powder form is 1040.
It is preferably about a sawtooth or less, particularly about 102 Ω·crn or less, and most preferably about 101 Ω·6nii degrees or less. actually 1
About 020·m to 10-20·ctn can be obtained,
Although they can be used in any way for the purpose of the present invention, those with excellent electrical conductivity are more preferred. The specific resistance (volume resistivity) of the powder is determined by filling an insulating cylinder with a diameter of 1crh with 5fr of 1ill of material, applying a cross-cutting force of 200kQ from the top with a piston, and applying a self-current voltage (e.g. 0001 to 1,000V).
) is applied (at a current of 1 mA or more) and measured.

The conductive V-element should preferably have a sufficiently small particle size, and the smaller the particle size, the lower the high conductivity when mixed with a polymer, often with a smaller mixing ratio. Although particles with an average particle size of 1 to 2 pm cannot be used, they are usually 1 μm or less, especially 0.5 μm.
Hereinafter, a thickness of 0.8 μm is most preferably used.

Particles with a particle size of 0.05 μm or less have excellent conductivity, but uniform dispersion tends to result in poor spinnability. After all, the particles e! ! 0.25μ
After ff1GU, i.e. 013μm~045μm
In particular, a thickness of about 0.15 μm to 0.85 μm is most practical.

Now, as mentioned above, the properties of the mixture of conductive particles and polymer vary greatly not only by the size of the particles and the mixing ratio, but also by the crystallinity of the positive polymer.

In other words, from the viewpoint of conductivity, it has high crystallinity (crystallinity 6).
0% or more, especially 70% or more) polymers such as polyethylene, polypropylene, polyolefins, polyoxymethylene, polyethers such as polyoxyethylene (polyethylene oxide), and their derivatives (e.g. block copolymers of polyethylene oxide/polyethylene terephthalate) ), phorinyl alcohol, polycaprolactone, etc. are preferred. In addition, polyamides such as nylon 6, nylon 66, and nylon 12, which are currently the most abundant, polyesters such as polyethylene terephthalate and polybutylene terephthalate, acrylic polymers, polyurethanes, and their paternal compounds (co-polymerized or Mixtures) are also suitable as polymers with which conductive particles are mixed.

Many of the above-mentioned bi-crystalline polymers have problems with heat resistance due to their low melting points, and the above-mentioned polyamides, polyesters, acrylic polymers, etc., which exhibit moderate crystallinity (crystallinity of about 20 to 50%) As the stretching ratio increases, the conductivity and antistatic properties tend to decrease, so it is necessary to select an appropriate polymer depending on the application.

The mixing ratio of conductive particles varies depending on the conductivity of the particles, particle size, chain-forming ability of the particles, and the properties and crystallinity of the binder polymer to be mixed, but is usually within a range of about 80 to 85% (Phoenix). Yes, and in most cases it is about 40-80%. 8
If it exceeds 0%, the fluidity will be insufficient, so it will be necessary to use a normal & kinetic improving agent.

As for the conductive particles contained in the sheath component of this dull light, conductive particles of metal oxides with high white discoloration or metal compounds with little coloring, or conductive particles with surface Particles with these coatings can be used. The particle size of the conductive particles is preferably comparable to the minimum thickness of the sheath component.

Although it is not impossible to use particles with an average particle diameter of more than four times the minimum thickness of the sheath component, particles with a diameter of 20 μm or more will cause many fisheye-shaped knots to occur and cause yarn breakage during spinning or twisting. Undesirable. On the other hand, if the average particle diameter is smaller than 0.2 times the minimum thickness of the sheath component, the antistatic performance improvement effect disappears. Therefore, the average particle diameter is most preferably within a range that satisfies (1) W below.

The fiber-forming polymer constituting the sheath component of the fiber of the present invention may be any IjAIL & type IA polymer, including polyamides such as nylon 6, nylon 66 and nylon 12, polyesters such as polyethylene terephthalate and polyethylene terephthalate, Acrylic polymers, polyolefins such as polyurethane and polypropylene, and modified products (copolymers or mixtures) thereof are suitable. In particular, the above-mentioned polyamides, polyesters, and acrylic polymers are currently most widely produced commercially, and are most suitable as polymers for the shaft component of conductive composite fibers, which are often used in combination with these synthetic fibers.

It is also possible to improve its dye receptivity by known methods (for example by copolymerizing to introduce basic or acidic dyeing sites) to facilitate blending or interdying with synthetic or natural fibers. Alternatively, matting agents, pigments, coloring agents, stabilizers, antistatic agents (polyalkylene oxides, surfactants, etc.), etc. can also be added.

The combination of polymers for the core and sheath components is preferably a combination of the same type or similar polymers from the viewpoint of preventing peeling due to stretching, etc. However, since the fiber of the present invention has a core-sheath structure, when it is made into a parallel type. Polymer combinations with exfoliation (
For example, even in the case of a combination of polyethylene and nylon 6), it is rare that the fibers are opened with such high electrical current.

Depending on the application, for example, when performing high-temperature treatment during Uonen steam jet bulking or false twisting, the conductive core component may be exposed. In such cases, it is necessary to select a polymer with a high melting point as the polymer for the sheath component.

The fiber of the present invention is a composite of a conductive core component made of the above conductive inorganic particles and a binder polymer, and a sheath component surrounding the conductive core component made of a fiber-forming polymer. The conductive core component must have sufficient conductivity, and generally needs to have a specific resistance of less than 10'Q·m, preferably 10'Q·m or less, and 102Ω·α The following are particularly preferred.

Although the sheath component contains 0.001 to 5% by weight of conductive particles, it is non-conductive and exhibits a specific resistance of about 10'Ω. Composite ratio of conductive core components (
Regarding cross-sectional area occupancy), conductive components containing a large amount of conductive inorganic particles tend to be inferior in spinnability, strength, and elongation.

Normally, it is preferably 80% or more, particularly 15% or less. On the other hand, as the composite ratio decreases, the conductivity becomes unstable and tends to decrease at shallow depths.
% or more is preferable, and 2% or more is particularly preferable.

Figures 1 to 8 are of the present invention! This is a specific example of a cross section of a bag, and FIGS. 4 and 5 are specific examples of a structure in which a conventionally known conductive component is formed into thin circles on the fiber surface.

The cross-section (contour) of the fibers of the invention may be circular or non-circular. Further, the conductive core component may be singular or plural, and may be circular or non-circular.

The fibers of the present invention are preferably partially thin in terms of the thickness of the sheath component, and can be produced by a conventional melt or dry composite spinning method. Preferably.

Such composite fibers are made possible by special consideration in the design of the cap. That is, (in the internal orifice of the A1 cap, the core component (2) and sheath component (1)
), the minimum thickness of the 1#1 component is 8 μm or more to form a poH@antibody. That,
ω) The flow velocity of the polymer before and after the conductive core component (2) and sheath component (1) merge at the internal orifice is approximately equal, and the flow velocity of the conductive core component (2) immediately before the merge is set to v.
2. When the flow velocity of the sheath component +11 is vl and the flow velocity of the composite flow immediately after merging is ■1+2, v2< v, < VI+1
(0) The isoelectric core component mixed with a large amount of conductive inorganic particles has high melt fluidity with an IJ4g breaking velocity of 103 sec-'pjA degrees or less, compared to ordinary m-thin-forming polymers. Since the shearing rate tends to become abrupt, it is necessary to set the shear rate at least immediately before merging to 10''5ec-16! degrees or higher to allow the merging to occur in a state that is the same as the melt fluidity of the sheath components.

Normally, it is not easy to maintain the minimum thickness of the sheath component below 8 μm. For example, in an eccentric core-sheath groove structure as shown in the figure, the conductive core component (2) and sheath component (1) are connected to P'
If the three orifices are simply converged eccentrically at one orifice 1, the minimum thickness of the sheath component will be approximately 4 μm or more, or the conductive core component will protrude to the surface.

Figure 7 shows a mixed band of conductive particles in the sheath component and a conductive composite fiber with a minimum thickness of 1.5 μm (the cross section is shown in Figure 1, 20 denier B filament). This is an example of a dragon breastplate. The antistatic property is Nylon 6 from Weitomi.
When knitting 100 tenier 24 filament false twisted yarn with 120 nine yarns, one out of every six yarns has a
The knitted fabric made of fibers was dyed, washed, dried, and then covered with a wool cloth of <151g JAlk on the upper right side of a wooden board in an atmosphere with a temperature and humidity of 25°C and 20%, and evaluated by the charge ratio of 1 minute. . According to this ifP price method? 1 voltage is IKV or higher.

Most of the damage caused by static electricity and wrinkles on carpets or work clothes in offices where the computer is used can be prevented. The mixing ratio is (1,001 to 5%), and 0.08 to 1% is the least practical.

At 0108 kyo mass %, there is a tendency for the charge and pressure to become worse and the dispersion to become larger, and for Q, 001 mu mass %, the improvement in antistatic performance is due to the lack of light. On the other hand, when 9% of lice is exceeded, the electrostatic potential reaches the same level as that of conductive pongee surface, and the improvement effect reaches saturation. And money consumption is the same.

The fibers of Honkabutsu are white or close to white, and @几 can produce white skin (reflectance) of 609b or higher, and conventional conductive multi-strand fibers of carbon black yarn were unsuitable. It can also be used for white or light colored textile products. It is in the form of a continuous filament or stable, and can be mixed with other chargeable natural fibers or man-made fibers in an uncrimped state or a crimped state to impart antistatic performance to textile products. The appropriate mixing rate is about 01 to 1 (l), but depending on the purpose, a mixing rate of 10 to 100% or less than 01% may be used adversely.
(In some cases, the mixing may be carried out by any known method such as blending, stand system, double twisting, blending, intersecting lines, interlacing knitting, etc.).

The above-mentioned example will explain the misfire. Figures indicate percentage by weight unless otherwise noted.

Example 1 A1 is a titanium oxide particle having a tin oxide (Sr:O2) film on its surface, mixed with 1.5% antemon oxide and fired to make the particle conductive. , A, has an average particle size of 0.
25 μm (the particle size variation range is 0.20 to 0.80 μm)
The content of oxidized fibers was 15%, the resistivity was 4.80, there were scratches, the appearance was pale gray-blue, almost white, and the light reflectance was 88%. In addition, the average particle size of conductive particles was 1.5 μm (the range of particle size variation was 1.0 μm) in the same way as A.
~2.0μm), specific resistance 1.60・particles, and 88% white skin A! shall be. 25% powder wound of nylon 6 (crystallinity 45%) with a molecular weight of 14,000 and 175% conductive first A
The conductive polymer obtained by mixing and melt-kneading the CP
, and so on. As a particle dispersant, polyethylene oxide/polybutylene 4th site block co-electrical metal material (combination ratio of 3 to 1) was used as a particle dispersant.
/1) Add 02% of a substance with a molecular weight of 4.000 to A1, and when mixing it with nylon 6 powder, add stearin butymagnesium salt to A1 as a fluidity improver.
% added.

Molecular method 16,000 nylon 6 with conductive particles A2 0
49b and 0.35% titanium oxide particles added as a matting agent as a sheath component (or protective component), and the conductive polymer CP as a conductive component, with a composite structure as shown in FIGS. 1 and 2. Melt spun.

The ratio (volume) of both components was 10:1, and the spinning temperature was 28.
It was spun from an orifice with a diameter of 0.25 m at 0°C and wound up at a speed of 800 m/min while cooling and oiling. Next, it was stretched at 90° C. and 24 times, and then brought into contact with a hot plate at 170° C., and then wound into a pirn while heating at 12 T/m to obtain a drawn yarn Y1 of 20-r′ 3-filament filament.
I got Y. In addition, comparative yarn drawing YL Y4 (composite structures are shown in FIGS. 4 and 1, respectively) was obtained. In addition, when drawing Y, nearly 90% of the threads were broken when the winding amount was 8001 or less, and incision scratches occurred in all the travelers. Table 1 shows the properties of these drawn yarns, such as conductivity, antistatic properties, and metal abrasion properties.

Conductivity was determined by bundling 80 single yarns of 10 lengths, connecting both ends with metal terminals and conductive adhesive, applying IKV DC voltage, measuring the resistance value, and calculating the conductive component from that. Evaluation was made by specific resistance.

Kinpeng's single wear resistance is 100% on a stainless steel wire with a diameter of 85μ.
When the thread is run at a speed of m/min (thread tension before contact 4
~5F, contact angle 45°) The cutting time of the stainless steel wire was evaluated.

Both Y and ~Y4 show excellent conductivity with a specific resistance of about 10"Ω・cIn, but Y4, which does not mix conductive particles in the sheath component, is significantly inferior in antistatic performance. In terms of properties, Y with a side-by-side structure is extremely poor. - It can be seen that Yl and Y, which are the fibers of the present invention, are excellent in both antistatic properties and gold 11I4N! abrasion resistance.

Next, each of Y and ~Y4 was combined with a 2600 denier 140 filament of nylon 6 thread and crimped, and used in one of the 8 courses, and for the other 2 courses, a 2600 denier 140 filament of nylon 6 thread was used. Tafkod carpet (loop, blending rate 0.26%) was produced using the same. Walking on the resulting carpet with leather shoes (25°C
2o%RH) L, human body belt [abdominal measurements] showed that the carpets mixed with fibers Y7 and Y of the present invention had excellent electrical training performance of -1, OKV and -0,9 KV, respectively. had.

-For carpets that use a mixture of 10,000, Y3, and Y4, that's the case.-
They were 0.9KV and -1.7KV. In addition, nylon 6
In a carpet made only of crimped yarn 2600 denier 140 filament, the human body voltage is -9.2 KV, and the electric discharge when touching the grounded handle is severe.
It caused a considerable sense of fear.

Table 1 Example 2 Molecule 1tso, ooo polyethylene (crystallinity 78%
) and about 25% of the conductive particles A17 used in the examples.
5% and further melt-kneaded to form conductive polymer CP2.
I got it. However, 0.2% of polyethylene oxide/polybutylene oxide block copolymer is added to A as a particle dispersant, and magnesium stearate salt is added as a fluidity improver when mixed with polyethylene powder.
It was added in an amount of 0.3% based on 1. conductive particles A, with polyethylene terephthalate of 15,000 molecules & 0.2
% and titanium oxide particles at 0.35% as a sheath component, and the above conductive polymer OF as a conductive core component,
The composite structure shown in FIGS. 1 and 8 was melt-spun (however, there was one conductive filament, and the remaining five were hybrid yarns consisting of non-conductive filaments without a conductive core component). That is, the composite ratio (volume) of both components in the conductive filament is 10:1, and the diameter is 0.25 at a spinning temperature of 295°C.
The material was spun from an orifice of 1,000 m/min and wound at a speed of 1,000 m/min while cooling and oiling. Then 90°C, 2.
After stretching 6 times and further contacting a hot plate at 170°C,
While heating at 2 T/m, the yarn was wound on a lahan (1) to obtain drawn yarns Y6 and Y6 of 20 denier 6 filaments. Further, as a comparative example, drawn yarn Y7 (composite structure is shown in FIG. 1) in which conductive particles M2 were not mixed in the sheath component was obtained. The structure and performance of these drawn yarns are shown in Table 2. The antistatic property was evaluated by the frictional charging voltage of a circular knitted fabric of false twisted yarn of polyethylene terephthalate 150 denier 48 funolament, in which one in six of the above conductive hybrid yarns was knitted.

Both Y and ~Y7 have excellent electrical conductivity with a specific resistance of about 1020 fibers, but in terms of antistatic properties, the knitted fabric mixed with the fibers Y and ~Y6 of the present invention has conductive particles in the sheath component. It can be seen that the antistatic performance is greatly improved compared to the knitted fabric in which Y7 is not mixed. The electrostatic voltage measured on a knitted fabric consisting only of false twisted yarn of polyethylene terephthalate 150 denier 48 filaments was -14.5 KV.

Next, the yarns Y and -Y were combined with ordinary polyethylene terephthalate 50 denier 24 filaments, respectively, and the iQ+ density taffeta (warp/warp density 800
The warp threads were woven at intervals of 5.1 W into the yarn (1/inch), and dyed and finished.

The amount of electrical charge of these dyed cloths (measured according to the static electricity safety guidelines issued by the Industrial Safety Research Institute of the Ministry of Labor) was 8.5.
2.6.7.2 x 10-' coulombs/d, and the fabric using the fibers Y5 and Y6 of the present invention complies with the standard value of 7 x 10-' coulombs/- or less of the static electricity safety guideline, and has excellent control. It can be seen that the fabric containing Y7, which is not mixed with conductive particles as a sheath component, is lacking in antistatic performance. In addition, the electrostatic charge nail measured with a highly durable tuff material made only of polyethylene terephthalate 70 denier 36 filament is 22X1.
It was 0-' coulomb/door.

Table 2

[Brief explanation of the drawing]

1 to 8 are specific examples of cross-sectional views of the present invention M. Figures 4 and 5 are examples of structures in which conductive components are exposed on the surface of 1ia pongee. Figure 6 shows that the minimum thickness of the sheath component is 1.5 μm.
Conductivity *@, 12 What is the mixing ratio of conductive particles in the sheath component and friction for Tsumugi? 4) This shows a specific example of voltage opening. 〃 Kanebo-EI, M Co., Ltd. - Law 11 I2j Appetizer 3rd Part 4 Sai 50 Material 6 Mixing Ratio ('/,) Procedure Amendment Book July 17, 1980 1, Display of Incident 1982 Patent Application No. 77781 2, Title of the invention: Conductive Injection Thread 8, Relationship with the person making the amendment: Tokusho Applicant address: 5-17-4 Hakuda, Zata-ku, Tokyo Contact address: Osaka City, 584 Kanebo Co., Ltd. Patent Department 6, 1-5-90 Tomobuchi-cho, Bejima-ku Contents of amendment (1) The description of the specification is amended as follows. (2) The elongation of Y2 in Table 1 on page 20 of the specification is ['l'
Correct the gold kI4 friction properties of lJ and Y to r8.1j, respectively. that's all

Claims (1)

[Scope of Claims] (1) A conductive core component having a specific resistance of less than 1070·α consisting of conductive particles and a thermoplastic polymer, and a conductive metal oxide or metal compound particle or a film thereof on the surface. Containing 0.001 to 5% of particles having a specific resistance of 1
A conductive composite fiber formed by combining a non-conductive sheath component made of a fiber-forming polymer of 070.0 or higher. (2) The fiber according to claim 1, wherein the sheath component has a minimum thickness of 8 μm or less in the cross section. (8) The fiber according to claim 1, wherein the particle size of the conductive particles contained in the sheath component is within a range that satisfies the following intermediate conditions. (4) The specific resistance of the conductive particles contained in the sheath component is 102Ω
- The fiber according to claim 1, which is less than or equal to B. (5) The conductive particles contained in the conductive core component are one type or a mixture of two or more types selected from the group of conductive metal oxides, metal compounds, metal acids, or particles having a film thereof on the surface. The fiber according to claim 1, which is