JPH0621395B2 - Carpet base cloth - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a carpet base cloth, and more particularly to a carpet base cloth having an antistatic property formed by weaving a stretched tape yarn of a conductive thermoplastic resin laminate.

With the advent of tufted carpets, carpets can be produced inexpensively and in large quantities. By laying a pile of synthetic fibers such as acrylic fibers and nylon fibers on the woven base fabric of drawn tape yarn of thermoplastic resin such as polypropylene. It is widely used not only for households but also for floors of transportation facilities such as buildings, offices, automobiles, and railroads, mainly for However, on the other hand,
There is an increasing problem that an electric shock is given to a human body due to the generation and accumulation of static electricity due to contact friction and the like, and that noise is generated and damage is caused to each model device such as a computer.

As a method for solving these problems, a method of weaving conductive fibers such as carbon fibers, metal fibers and metal plated fibers into a base cloth, a method of mixing a conductive substance into a backing material, a method of mixing an antistatic agent into a pile material or a pile It has been proposed to apply it to the. However, these methods have insufficient antistatic effects, and the former two methods have problems in terms of economic efficiency and the latter method in terms of durability, and therefore they do not sufficiently meet market needs. The current situation is that no solution has been obtained.

For example, JP-A-52-42975 discloses a slit-shaped fiber obtained by drawing a composition obtained by blending an organic polymer such as nylon or polypropylene with 0.01 to 9% by weight of carbon fiber having a diameter of 20 μm or less. A carpet base cloth in which (tape yarn) is plain-woven is disclosed. Since carbon fiber is used as a conductive substance in this method, only 9% by weight can be blended in at most from the aspect of stretchability, and it cannot be said that the conductive effect on the carpet base cloth is sufficient. Further, the thickness of the stretched tape yarn becomes too thick to allow stretching, which is economically disadvantageous.

In view of the above-mentioned present situation, the present invention has been made for the purpose of providing a carpet base cloth capable of producing a carpet having excellent antistatic performance even in a low humidity state, particularly a tufted carpet base cloth, More specifically, the carpet base fabric of the present invention has one or both surfaces of a base material layer (not containing carbon black) of a thermoplastic resin,
A layer having a thickness of at least 0.3 μ formed by a conductive thermoplastic resin composition containing 10 to 30% by weight of carbon black having a specific surface area of 500 m ² / g or more (thinner than the thickness of the base material layer. A carpet base fabric formed by weaving a stretched tape yarn of a thermoplastic resin laminate having a thickness of at least one of warp yarns and weft yarns.

The thermoplastic resin constituting the substrate layer and the layer of the conductive thermoplastic resin composition in the present invention, polyethylene,
Examples thereof include polyolefins such as polypropylene and ethylene-propylene copolymers, polyamides, polyesters, and the like.

Also, carbon black has a specific surface area of 500 m ² / g.
It is essential that the above is satisfied, and if the specific surface area is less than 500 m ² / g, a carpet having sufficient antistatic performance cannot be obtained. Specific examples of the carbon black having a specific surface area of 500 m ² / g or more can be selected from conductive furnace black, super conductive furnace black, extra conductive furnace black, and the like. Cheng Black EC "(trade name) is preferable.

In the present invention, the specific surface area is measured by the BET method using nitrogen gas, which is the most general, and the details of the measuring method are described in, for example, March 15, 1980.
Japan-Maruzen Co., Ltd. "Chemical Handbook Application Edition (Revised 3rd Edition)"
Pp. 688-689.

To prepare a conductive thermoplastic resin composition from the thermoplastic resin to be the surface layer and the carbon black, if necessary, a heat stabilizer, a light stabilizer, a pigment, a lubricant, a blocking agent, a flame retardant, etc. It may be further added and melt-kneaded by a known method such as Banbury, roll, Brabender, single-screw extruder, or twin-screw extruder.

At this time, it is necessary to prepare the composition so that the carbon black is contained in an amount of 10 to 30% by weight. If the carbon black content in the composition is less than 10% by weight, a carpet having sufficient antistatic performance cannot be obtained, and even if the content exceeds 30% by weight, the antistatic property accompanying the increase This is because the performance improvement effect is not recognized and only an economic disadvantage is brought about.

The stretched tape yarn of the thermoplastic resin laminate in the present invention comprises a laminate having a layer made of the conductive thermoplastic resin composition on one surface or both surfaces of a base material layer made of a thermoplastic resin, an oven, and a roll heat. It can be obtained by a known method using a plate or the like, usually by uniaxially stretching.

In that case, the layer of the conductive thermoplastic resin composition of the stretched yarn of the laminate must have a thickness of at least 0.3 μ. This is because if the thickness is less than 0.3 μm, a carpet having sufficient antistatic performance cannot be obtained. Further, the thickness of the layer is thinner than the thickness of the base material layer. The stretched tape yarn made of this laminate is a method of laminating both by a known method such as sequential extrusion lamination, coextrusion lamination, and dry lamination before stretching,
It can be obtained by any of the methods in which both are stretched and then laminated.

In the present invention, “at least 0.3 μ on one or both surfaces”
The thickness part of the drawn tape yarn of the thermoplastic resin laminate formed by the conductive thermoplastic resin composition containing 10 to 30% by weight of carbon black having a specific surface area of 500 m ² / g or more, It has the same meaning as described above.

The drawn tape yarn generally has a draw ratio of 3 to 9 and a fineness of about 250 to 1500 denier.

The carpet base fabric of the present invention is a through-sizer type in which the drawn tape yarn of the thermoplastic resin laminate is used for at least one of the warp and weft, and the number of threads per 2.54 cm width of each yarn is about 12 to 30. It is obtained by weaving using a loom, a water jet loom, a circular room and the like.
The carpet base fabric of the present invention is not limited to the case where the stretched tape yarn is used for at least one of the warp yarns and the weft yarns as described above, and depending on the required level of various applications, for example, three yarns of each yarn are used. It also includes a case where the drawn tape yarn is mixed with the conventional drawn tape yarn at a ratio of 1 to 5 to 1 to 5.

The carpet manufactured by using the carpet base fabric of the present invention described above has excellent antistatic performance that could not be achieved by the conventionally known technique, particularly antistatic performance that is not affected by environment such as humidity. It has the effect of excellent sustainability of anti-static performance.

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

Examples 1 to 5 and Comparative Examples 1 to 5 Carbon black “Ketjen Black EC” manufactured by Lion Akzo Co., Ltd. having a specific surface area of 1000 m ² / g and polypropylene (melt flow rate 6.5 g / 10 min) manufactured by Mitsubishi Petrochemical Co., Ltd. Was melt-kneaded with a Banbury mixer, and pelletized conductive thermoplastic resin compositions having carbon black contents of 9% by weight, 15% by weight and 30% by weight were obtained by a pelletizer. Also,
Similarly, using carbon black "Ketchen Black EC" manufactured by Lion Akzo Co., Ltd. having a specific surface area of 520 m ² / g,
A composition having a carbon black content of 15% by weight was obtained. Further, a furnace black (Vulcan XC-72) manufactured by US Cabot Co. having a specific surface area of 220 m ² / g was used to obtain a composition having a content of 30% by weight.

Next, the 40φ extruder was charged with the above composition, and the 90φ extruder was supplied with Mitsubishi Yuka Co., Ltd. polypropylene (melt flow rate 5.0 g / 10 g).
Min.) Was supplied and coextruded to obtain a sheet-like material having a total thickness of 40 μ having the above-mentioned composition layers of various thicknesses on one surface or both surfaces. This sheet material is uniaxially stretched 4 times with a roll stretching machine to give a thickness of 0.25 μ, 0.5 μ of the conductive resin composition of 1000 denier.
And 1 μ of drawn tape yarn was obtained. Also, 500 denier and 1000 denier drawn tape yarns without the above composition layer were prepared. The properties of the obtained thermoplastic resin stretched tape yarn are as shown in Table 1.

Using the drawn tape yarn, a carpet base cloth shown in Table 2 was woven with a through-saw type loom. Nylon semi-worsted yarn pile was planted on this base cloth with a tufter (5/64 gauge) manufactured by Hiraoka Industry Co., Ltd. to produce a carpet. Table 2 shows the antistatic performance of the carpet.

Comparative Example 6 In Example 1, instead of 15% by weight of carbon black, carbon fiber 15 having a fiber diameter of 8 μm and a fiber length of 3000 μm was used.
When a drawn tape yarn was produced in the same manner except that the weight% was used, it was difficult to draw, and the appearance of the drawn tape was poor (the carbon fiber was exposed from the conductive layer or partly dropped). .

A stretched flat yarn having this poor appearance and a stretched tape yarn obtained in Production No. 9 were woven and used as a carpet base fabric, and a tufted carpet obtained in the same manner as in Example 1 was used as a base fabric under a humidity of 40% RH. Volume resistivity is 3 × 10 ¹⁶ Ω ・
The surface resistance of the carpet was 9 × 10 ¹⁴ Ω.

Comparative Example 7 15% by weight of carbon fiber having a specific surface area of 0.26 m ² / g and a fiber length of 3000 μ and polypropylene (melt flow rate 6.5 g / 10 minutes) manufactured by Mitsubishi Yuka Co., Ltd. were melt-kneaded in a Banbury mixer, Pelletized with a pelletizer.

Next, the pellets were fed to a 40ψ extruder and extruded to 40
A sheet of μ was obtained. When this sheet material was uniaxially stretched 4 times with a roll stretching machine to obtain a 1000 denier stretched tape, stretch breakage occurred.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Ito 1 Toho-cho, Yokkaichi-shi, Mie Prefectural Resin Research Laboratory, Mitsubishi Petrochemical Co., Ltd. (56) References JP-A-52-42975 (JP, A)

Claims (1)

[Claims] 1. A specific surface area of 50 or more on one surface or both surfaces of a base material layer (not containing carbon black) of a thermoplastic resin.
At least formed by a conductive thermoplastic resin composition containing 10 to 30% by weight of carbon black of 0 m ² / g or more
Weaving using a stretched tape yarn of a thermoplastic resin laminate provided with a layer having a thickness of 0.3 μ (thickness smaller than that of the base material layer) on at least one of warp and weft. Carpet base cloth made by.