JPH06260296A - Static eliminating sheet body and carpet using same - Google Patents

Abstract

PURPOSE:To provide a carpet excellent in static eliminating performance by constituting a sheet body from two kinds of conductive, short fibers different in aspect ratio, and setting the fiber length of the low aspect ratio component shorter than that of the high aspect ratio component. CONSTITUTION:A sheet body is formed of two kinds of conductive short fibers different in aspect ratio. The fiber length of the low aspect ratio component is set shorter than that of the high aspect ratio component. The aspect ratio of the conductive fiber is about 2000-2500, and the mixing quantity is about 5%. In the sheet, the conductive short fibers are preferably arranged in such a manner that a part of the conductive short fibers can regularly make contact with the atmosphere. As the constituting fibers, any of natural fibers, pulp artificial fibers, synthetic fibers, and mixtures thereof may be used, but the synthetic fibers are preferred from the viewpoint of water resistance. For the sheet state, the sheet is preferably formed by dispersing a polymer having a melting point lower than the fiber constituting the sheet state in the sheet followed by thermal fusion. As the conductive short fibers, metal fibers, carbon fibers, metal plated fibers and others are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static electricity removing sheet for removing charged static electricity by discharging. To be more specific, use as a sheet for a rug's base cloth by removing static electricity by approaching or contacting a charged object, or by flocking a woven cloth into a base cloth such as a carpet, an automobile mat, an entrance mat, or a passenger compartment mat. The present invention relates to a sheet-like body for static electricity removal which can remove static electricity by being attached to a carpet after flocking or used at the time of molding.

[0002]

2. Description of the Related Art Conventionally, the following methods have been proposed as methods for reducing obstacles due to frictional electrification involving the human body.

(1) Measures against generation source This is a measure to reduce the amount of static electricity generated, and the selection of the material of the human body attachment such as clothes or the material of the object to be rubbed, and the addition of the surfactant to them. There is a method such as.

(2) Leakage and diffusion of generated static electricity This is to diffuse or leak the generated static electricity in a wider area to reduce obstacles. There is a method of using a relatively high material, or a method of reducing local electrification by setting the environment to have high humidity.

(3) Elimination of electrostatic discharge by charging A method of removing static electricity by bringing a charged object into contact with a discharge sheet, for example, a sheet containing highly conductive fibers, and discharging from the tips of the conductive fibers protruding into the air.

In the above methods (1) to (3), general electrostatic damage has reached a level where practically there is no problem due to individual measures or combined measures.

[0007]

Among the above-mentioned conventional techniques,
The method of removing static electricity by discharging, which is the method of (3), is a prize because even if the human body is charged to a level that causes damage, it is possible to instantaneously reduce the discharge voltage to an extremely low level. As a specific method for producing the sheet, there is a method proposed in JP-A-62-156395. Further, a proposal described in JP-A-2-14936 has been made as an automobile mat to which this is applied.

If the methods of these known examples are adopted, under normal circumstances, no discomfort due to static electricity will occur under the environment, but in recent years, clothes, shoes, or automobile seats,
The materials used for automobile mats are diversified, and the human body is exposed to an extremely dry environment in a closed room. In the case where a discharge is needed instantaneously, the selection conditions within the range of the above proposal are still insufficient.

Therefore, the inventors of the present invention have earnestly studied practical improvement measures for the method of removing static electricity by discharging, which is the method (3) in the above-mentioned prior art, and arrived at the present invention.

That is, the present invention relates to a sheet-like body having an excellent removing performance in a sheet-like body for removing static electricity for the purpose of removing static electricity charged in a machine, an object, a human body, etc. by discharging. The invention proposes a practical method capable of instantaneously lowering the human body voltage, which is once charged to a level at which it impairs the human body, to 3 KV or less, which does not cause any discomfort to humans.

[0011]

In order to achieve the above object, the present invention has the following constitution.

That is, in a sheet-like body composed of fibers containing conductive short fibers, the conductive short fibers are composed of at least two kinds of conductive short fibers having different aspect ratios, and fibers having a low aspect ratio component. A static electricity removing sheet comprising a fiber having a length shorter than the fiber length of the high aspect ratio component, and further including a part of the conductive short fibers arranged so as to be able to contact with the atmosphere. is there.

A carpet characterized in that the above sheet-like body is used as a base fabric, and fiber bundles containing a mixture of conductive fibers are flocked as pile yarns.

Furthermore, a carpet in which the sheet-like body is used as a backing cloth, and a fiber bundle containing a mixture of conductive fibers is piled as pile yarns, the backing cloth being in direct contact with the pile yarns, or It is a carpet stuck via a conductive adhesive.

The present invention will be described in detail below.

The sheet-like material of the present invention is characterized by containing conductive short fibers having two or more kinds of aspect ratios (fiber length / fiber diameter), which have different lengths and have a low aspect ratio. Short fibers (low aspect ratio component) contain conductive short fibers whose fiber length is shorter than fibers with high aspect ratio (high aspect ratio component), and a part of these conductive short fibers is constantly exposed to the atmosphere. Including those arranged to be accessible.

With such a structure, conventionally,
There is a leap in technology in mixing electrically conductive short fibers with a length within the range that cannot be used when mixed alone with other electrically conductive short fibers having a short fiber length. When used in combination with conductive short fibers, it has the effect of increasing the dispersibility of conductive short fibers with a long fiber length, and even when used alone, it is possible to use conductive short fibers of a length that was previously difficult to use due to non-uniform dispersion. None, or it became possible to mix conductive short fibers having a long fiber length up to a high mixing ratio, which was difficult to mix.

Therefore, the conductive short fibers used in the present invention are
Not only are there differences in aspect ratios, it is important that there are differences in length, and it is important that the low aspect ratio component is shorter than the fiber length of the high aspect ratio component.

Further, not only is the incorporation of a high aspect ratio component having a long fiber length to obtain a high static elimination ratio which cannot be achieved conventionally, and the improvement of dispersibility is not only achieved by the incorporation of a low aspect ratio component having a short fiber length, The electrostatic capacity of the static elimination sheet can be increased. Furthermore, since many conductive short fibers that have a part that can be constantly contacted with the atmosphere can be effectively arranged, a large amount of static electricity can be discharged instantly even on an object with a limited area such as a mat. It is possible to impart a performance capable of preventing a failure. Next, the static elimination performance of the present invention will be described in detail.

Carbon fibers as conductive short fibers are dispersed and mixed with polyester short fibers (hereinafter referred to as PET) in water to form a sheet of 20 g / m ² by a papermaking method, and nylon BCF (bulked BC with continuous filament) and conductive yarn partially mixed
The F yarn was tufted by the tuft method to form a carpet, which was made into an automobile mat of 0.4 m ² and rubbed under the following conditions and then stood on the mat to measure the peeling electrification voltage of the human body. On the other hand, the static elimination rate was calculated from the difference by using the human body voltage measured on the mat after rubbing in the same manner as above, with the blank being the same as the above, except that the base cloth made of PET alone was flocked with the same standard.

Measurement conditions for peeling electrification voltage of human body: In a temperature control room of 20 ° C. and 20% RH, an insulating material is laid on a conductive material (aluminum), a seat is set on the insulating material, and a mat to be evaluated is attached. Rub the back and hips 10 times to focus and measure the electrification voltage of the human body. As the friction material, JIS wool clothes and rubber sole sports shoes were worn. The measurement of the electrification voltage is a potential meter SV-73A manufactured by Japan Static Co.
Used mold.

FIG. 1 shows the relationship between the aspect ratio of mixed fibers (fiber length L / fiber diameter D) and the static elimination rate obtained by the above method. As is clear from FIG. 1, the static elimination rate increases as the aspect ratio increases, but it is not necessarily proportional, and it gradually becomes a peak.

FIG. 2 shows the carbon fiber mixture ratio (% by weight).
And the static elimination rate. As is clear from FIG. 2, it can be seen that the same tendency as the aspect ratio can be seen in the amount of conductive short fibers mixed.

Generally, a human body voltage generated by friction caused by a non-conductive object such as walking or a backrest of a chair and a human body motion becomes 10 KV or more after an activity. Therefore, in order to reduce the obstacle to 3 KV or less, 70 after activity
A static elimination rate of at least% is required.

In order to obtain this level of static elimination rate, it is necessary for the specs and the amount of the conductive fibers to have an aspect ratio of about 2000 to 2500 and about 5% or more for the amount of mixing, as shown in FIGS. As can be seen, further increasing the aspect ratio or further increasing the mixing ratio is not a technically practical method because of non-uniform dispersion due to fiber entanglement.

Therefore, the inventors of the present invention examined the uniform dispersion, the increase of the mixing amount, and the improvement of the static elimination effect. As a result, as shown in FIG. 2, conductive short fibers having a specific aspect ratio difference and fiber length difference were mixed. As a result, it was found that the uniformity of dispersion of the fibers having a high aspect ratio can be increased as compared with the case where the fibers are mixed alone, and the static elimination rate can be improved as compared with the case where the fibers having a high aspect ratio are mixed alone. This is a surprising finding that cannot be inferred from conventional findings, and the adoption of this method makes it possible for the first time to increase the static elimination rate to a level that does not cause electrostatic damage even in a mat with a practically limited area. It is what

The sheet may be formed by any of a wet papermaking method, a needle punching method, a resin-bonded non-woven fabric method, a spunbond method, etc., but the conductive short fibers can be uniformly dispersed and the conductive short fibers can be dispersed. The wet papermaking method is the most preferable because it is easy to dispose the conductive short fibers so that a part of them can always contact the atmosphere.

It is not necessary for all of the conductive short fibers to be arranged so that a part thereof can always be in contact with the atmosphere, but a large number thereof is preferable because excellent static elimination performance is achieved. In addition, it is preferable that the portion that can be brought into contact with the atmosphere is near the tip of the short fiber because the surface area of the contact portion is large and contact is easy.

The constituent fibers are natural fibers,
Pulp artificial fiber, may be any synthetic fiber, etc., or may be a mixture thereof, but the strength of the sheet, those having a synthetic fiber as a main component from the viewpoint of water resistance, particularly strength, water absorption, rigidity, thickness, And the single yarn fineness of 0.
Polyester fiber having a denier of 1 to 1 and a fiber length of about 1 to 6 mm, preferably PET.

Further, in the sheet-like body, it is possible to disperse a polymer having a lower melting point than the fibers constituting the sheet-like body in the sheet and form the sheet by heat fusion, to obtain water resistance, adhesive strength and conductivity. It is preferable for forming and fixing a part of the short fibers so that they can always contact the atmosphere.

The polymer having a low melting point is not particularly limited as long as it has a lower melting point than the fibers constituting the sheet-like body, and conventionally known polymers / copolymers such as polyethylene, polypropylene, polyamide, polyester and the like can be used. Can be used.

The conductive short fibers have an intrinsic volume resistivity of 5.0.
As long as it is smaller than about 10 ⁻³ Ω · cm, and examples thereof include metal fibers, carbon fibers, metal-plated fibers, conductive agent adsorbing fibers, etc., carbon fibers are particularly easy to obtain fibers having a large aspect ratio. Is preferred.

As the high aspect ratio component of the conductive short fiber, the aspect ratio is 1500 or more, preferably 2500.
As described above, more preferably 3,000 or more, and having a fiber length of 13 mm or more, preferably 20 mm or more, more preferably 24 mm or more, 3% or more, preferably 5% or more, of the total weight of the fibers constituting the sheet, More preferably, it is contained at 7% or more. Aspect ratio is 15
When the fiber length is less than 00, and the fiber length is less than 13 mm, the static elimination effect is small and the static elimination ratio is not practically sufficient, and even when the content is less than 3%, the static elimination ratio is not practical, which is not preferable. On the other hand, if the aspect ratio exceeds 3500,
If the fiber length exceeds 27 mm, or if the content exceeds 7%, even if a low aspect ratio component fiber with a short fiber length is mixed, it is practically adopted due to unevenness due to entanglement of the high aspect ratio component fiber. Tends to be difficult.

As the low aspect ratio component, one having an aspect ratio of less than 1500 and a fiber length of 10 mm or less, preferably 7 mm or less, and more preferably 5 mm or less can be used as a high aspect ratio component and a combined sheet. 5% or more, preferably 7% or more, of the total weight of the constituent fibers,
More preferably, it is contained by 10% or more. If the aspect ratio is 1500 or more, the entanglement between the conductive short fibers tends to increase, and it is difficult to obtain the effect of improving the dispersion of the high aspect ratio component, which is not preferable. In the range where the fiber diameter is practical and can be manufactured and handled, the length is preferably in the range of 4 mm to 10 mm from the viewpoint of improving the dispersibility and the static elimination property. Regarding the content, if the total amount of conductive fibers is less than 5%, it tends to be difficult to practically obtain the effect of preventing electrostatic damage in the case of a limited area such as a mat formed by molding a carpet into a small size. On the other hand, even if the content exceeds 12%, the static elimination effect reaches the ceiling, the cost is high and the effect cannot be expected so much, and it is difficult to disperse uniformly, so that the practical mixing amount is 8 to 12 % Range is preferred.

The most preferable sheet forming method to which the present invention is applied is a wet papermaking method, one example of which is described below.

Single yarn fineness about 0.2 denier, length 2 mm
2% or more of carbon fibers having different aspect ratios within the scope of the present invention with respect to the PET short fibers of about 10% based on the PET weight, and the short melting point fibers obtained by the copolymerization of nylon 6 and 66. About 3% of the weight of PET is put into water, and while being uniformly dispersed, it is poured onto a mesh conveyor, dehydrated, transferred to a roller dryer and dried, and then thermocompression-bonded to melt the low melting point component. PET and carbon fiber are adhered to form a sheet-like body.

At this time, the sheet-like body is porous and is formed while maintaining a state in which a part (particularly the tip part) of the conductive short fibers is always in contact with the atmosphere. Therefore, PE
If an excessive amount of the low melting point component is used with respect to the amounts of T and carbon fiber, the surface of the sheet-like body will be completely covered,
It is preferable to adjust the amount of the low melting point component so as not to do so, or to partially carry out the melting point adhesion with a heat roller having an uneven surface.

Next, a practical use of the sheet-shaped body will be described.

The present sheet-shaped body is itself or another cloth,
It is needless to say that it can be laminated with paper, non-woven fabric or the like to form a static elimination sheet, but in the case of carpets, the following usage is effective.

(1) For carpet base cloth FIGS. 3 and 4 are schematic sectional views showing an example of the carpet according to the present invention.

FIG. 3 shows an example in which the sheet-like body of the present invention is used as it is as a carpet base cloth, and the ordinary pile yarn 2 and the conductive fiber 3 are mixed through the sheet-like body 1. The pile yarn 4 is flocked by a method such as tufting. The piled pile yarn is fixed to the sheet-like body 1 of the present invention as a base fabric with an adhesive or a backing material 5. At this time, one surface of the sheet-shaped body of the present invention is not in a closed state but is in the form of a porous non-woven fabric, and the conductive fibers 6, 7 mixed in the sheet-shaped body 1 of the present invention are partially (tips or the like) 6 ', 7 ′ Is always in contact with the atmosphere.

The adhesive or backing material 5 is
It is preferable to use conductive materials containing conductive powders or fibers. When used as a mat, it is cut and molded into mats.

FIG. 4 shows an example in which the sheet material of the present invention is used as a carpet base cloth by laminating it onto a normal carpet base cloth. The sheet body 8 of the present invention is a general carpet base cloth 9.
Is bonded to each other in a spot-bonding or lattice-like manner with an adhesive, and using the laminated sheet as a base fabric, a normal pile yarn 10 and a pile yarn 12 containing a mixture of conductive fibers 11 are formed by tufting or the like. Hair is pierced through the cloth.

After the piled yarns are fixed with an adhesive or a backing material 5, the backing cloth 1 for lining is fixed.
3 is pasted together. At this time, it is important not to completely seal both sides of the sheet-like body of the present invention with a resin or the like. In this example, the base cloth 9 and the sheet-like body 8 of the present invention are point-bonded,
Most of the upper surface of the sheet-shaped body 8 of the present invention is kept in the form of a porous non-woven fabric, and the conductive fibers 14, 15 mixed in the sheet-shaped body 8 of the present invention have a part (such as tips) 14 ', 15'. It is always in contact with the atmosphere.

Incidentally, the carpet base cloth 9 of FIG. 4 according to the present example.
In the adhesive base fabric of the sheet-like body 8 of the present invention, the contact between the conductive fibers 14 'and 15' and the atmosphere can be further increased by reversing the upper and lower (front and back) relations.

(2) Carpet for backing cloth FIG. 5 is a schematic view showing another example of the carpet according to the present invention.

FIG. 5 shows an example in which the sheet-like material of the present invention is used as a backing cloth for carpet.

A normal pile yarn 16 and a pile yarn 18 containing a mixture of the conductive fibers 17 are pierced through the ordinary base cloth 19 by a method such as tufting to be flocked. The piled yarns 16 and 18 that have been flocked are fixed to the base cloth 19 and the sheet-like body 22 of the present invention as a backing cloth through an adhesive or a backing material 21 containing a conductive substance 20. The present carpet can be adhered to the floor, laid or cut-molded into mats.

The same effect can be obtained by simply inserting the sheet-like body of the present invention as a carpet underlay without adhering it to the carpet.

Further, it is necessary for a charged object such as a human body to have a conductive substance mixed in a part of the pile yarn or a conductive substance at the time of adhesion or backing for fixing the piled pile yarn. When I got on the carpet,
By these, static electricity is diffused over the entire surface of the sheet-like body of the present invention, and it is possible to discharge instantly from a part of the conductive fibers in the sheet-like body of the present invention which is always in contact with the atmosphere scattered over the entire surface of the sheet. As a result, a great charge eliminating effect can be obtained.

Therefore, in any of the above cases (1) and (2), if the resinous material is hermetically applied to both surfaces of the sheet-shaped material of the present invention, a part of the conductive fibers cannot always come into contact with the atmosphere. It is not preferable because the effect of eliminating static electricity cannot be sufficiently obtained.

[0052]

EXAMPLES Next, the present invention will be described more specifically with reference to examples.

Polyethylene terephthalate (PET) short fibers having a single yarn fineness of about 0.2 d and a length of about 2 mm, and Tables 1 and 2
The carbon fiber having the diameter, fiber length, and mixing ratio (% by weight relative to the PET short fiber weight) shown in Fig. 3, and a core-sheath composite short fiber having a low melting point component as a sheath as a binder (PET as the core component and isophthalic acid at 40 mol% Copolymerized polyethylene terephthalate as a sheath component, core / sheath ratio = 50/50.
Melting point of sheath component 95-110 ° C. ) Is mixed with about 3% of the weight of PET short fibers, put into water, and while being uniformly dispersed, poured onto a mesh conveyor, dehydrated, transferred to a roller dryer, dried, and then thermocompression bonded. Then, the low melting point short fiber component was melted to bond the PET short fiber and the carbon fiber to form a sheet-like body.

The sheet-like material obtained by the above wet papermaking method is
A polyester non-woven fabric used as a normal car mat base fabric is laminated with a conductive adhesive to form a static-eliminating base fabric as shown in FIG.
Using a yarn (1600D-68F), a car mat was prepared with a basis weight of 1200 g / m ² .

Each evaluation sample (car mat area 0.4 m
^The results of evaluating the dispersibility of carbon fiber in water and the static elimination rate of the carmat during the papermaking of ² ) are also shown in Tables 1 and 2.

Level Nos. 1-1 to 1-15 are cases in which carbon fiber having one kind of specifications was mixed as the conductive short fiber. Level Nos. 1-1 to 1-6 have good dispersion uniformity of carbon fibers in water at the time of papermaking, but have low static elimination ratio, and the performance as a mat for removing static electricity is not satisfied.

On the other hand, the carbon fiber specification levels No. 1-8 to 1-11 and 1-14 to 1-15, which have a relatively high static elimination rate, are used when the aspect ratio of the carbon fiber is considerably increased or when the mixing ratio is changed. Although the values are considerably increased, the dispersibility of the carbon fibers becomes worse as the charge removal rate is improved, and the specifications or mixing ratio of the carbon fibers that can satisfy both the charge removal rate of the mat and the dispersibility of the carbon fibers are high. I know there isn't.

Next, the levels Nos. 2-1 to 2-10, 3-1 to 3-5, 4-1 and 4-2 according to the mixing specification according to the present invention can satisfy both characteristics. I understand. We were able to determine the optimum mixing specifications by taking into consideration the required static elimination ratio of the product, workability of papermaking, and sheet quality.

Even when two kinds of carbon fibers having different specifications are mixed, the level No. 5-1 shows that the smaller the aspect ratio, the longer the fiber length is. It is bad and cannot be put to practical use in terms of workability and sheet quality.

Level No. 6-1 is an example in which carbon fibers having three types of specifications are mixed. In this case, one type of high aspect ratio component and the other two types of low aspect ratio components have their dispersibility. It is possible to satisfy the dispersibility and the charge removal property by these interactions.

[0061]

[Table 1]

[Table 2]

[0062]

EFFECT OF THE INVENTION The sheet-like material of the present invention has a length within a range that cannot be conventionally used when electrically conductive short fibers are mixed alone, but is mixed with electrically conductive short fibers having a short fiber length. By using in combination, an effect of increasing the dispersibility of the conductive short fiber having a long fiber length is produced, and even a short length of the conductive short fiber which has been difficult to use due to the non-uniform dispersion can be used alone, or, It is possible to mix conductive short fibers with a long fiber length up to a high mixing ratio, which was difficult to mix, and moreover, a large number of conductive short fibers having a part that can always contact the atmosphere are effectively arranged, so that it is possible to use it like a mat. Even a large area of static electricity can be instantly discharged even on an object with a limited area,
It is possible to impart performance capable of preventing electrostatic damage.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between an aspect ratio of mixed fibers and a static elimination rate.

FIG. 2 is an explanatory diagram showing a relationship between a carbon fiber mixture ratio and a static elimination ratio.

FIG. 3 is a schematic sectional view showing an example of a carpet according to the present invention.

FIG. 4 is a schematic cross-sectional view showing another example of the carpet according to the present invention.

FIG. 5 is a schematic sectional view showing still another example of the carpet according to the present invention.

[Explanation of symbols]

1, 8, 22: Sheet-like body according to the present invention 2, 10, 16: Pile yarn 3, 11, 17: Conductive fiber 4, 12, 18: Pile yarn in which conductive fiber is mixed 5: Backing material 6,7,14,15: Conductive short fibers 6 ', 7', 14 ', 15': A part of the conductive short fibers that can always contact with the atmosphere 9,19: Carpet base fabric 13: Backing fabric 20: Conductive Substance 21: Conductive adhesive / backing material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoho Mashita 1-1-1, Sonoyama, Otsu City, Shiga Prefecture Toray Co., Ltd. Shiga Plant

Claims (5)

[Claims] 1. A sheet-like body formed of fibers containing conductive short fibers, wherein the conductive short fibers are composed of at least two kinds of conductive short fibers having different aspect ratios,
And a fiber length of the low aspect ratio component is shorter than a fiber length of the high aspect ratio component, and further, a part of the conductive short fibers is arranged so as to be able to come into contact with the atmosphere. Sheet-like body for removing static electricity. 2. A conductive short fiber is a carbon fiber and is composed of a high aspect ratio component having an aspect ratio of 1500 or more and a fiber length of 13 mm or more and a low aspect ratio component having an aspect ratio of less than 1500 and a fiber length of 10 mm or less. 2. The sheet material for static electricity removal according to claim 1, wherein the high aspect ratio component is contained in an amount of at least 3% by weight or more, and the conductive short fibers as a whole are contained in an amount of 5% by weight or more. 3. The sheet-like body is formed into a sheet by a wet papermaking method mainly using polyethylene terephthalate short fibers, and heat-bonded with a polymer having a lower melting point than the polyethylene terephthalate short fibers. The sheet-like body for static electricity removal according to 1 or 2. 4. A carpet obtained by using the sheet-like body according to claim 1 as a base cloth and flocking fiber bundles containing a mixture of conductive fibers as pile yarns. 5. A carpet in which the sheet-like body according to claim 1 is used as a backing cloth, and a fiber bundle containing a mixture of conductive fibers is piled as pile yarns, the backing cloth being in direct contact with the pile yarns. Carpet attached with a conductive adhesive.