JP2969885B2 - Base material for adhesive tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a base material for an adhesive tape which is excellent in hand-cutting property, water resistance and smoothness.

[Problems to be solved by conventional technology and invention]

Conventionally, as an adhesive tape obtained by attaching an adhesive to a base material, a cloth base material obtained by laminating polyethylene on a cotton cloth or rayon cloth, or polyethylene on a flat yarn or multifilament base cloth of a polyolefin or polyester resin is used. Laminated plastic-based substrates have been used. However, those using a cloth base material require the use of an adhesive when laminating polyethylene, which is not only complicated but also leads to an increase in cost. Further, despite the use of an adhesive, there is a problem in physical properties that water resistance is poor. Further, the tape has a drawback that it is bulky when wrapped in a long length because it is thick, and is difficult to handle because it is heavy.

On the other hand, the one using a plastic base material has a problem in that if it is forcibly cut, the thread at the cut end is frayed because the hand-cutting property is insufficient, so that it cannot be cut cleanly. In order to improve the hand-cutting property, there have been proposed ones in which the denier of the weft and the warp is changed or in which the number of yarns is changed, but these have problems such as lack of smoothness of the substrate surface. doing.

[Means for solving the problem]

The present inventors have conducted intensive studies in consideration of such points, and as a result, have found that by using a polyolefin-based multifilament cross-linked to a weft, it is possible to provide a pressure-sensitive adhesive tape base material that has solved the above problems. The present invention has been reached.

That is, the present invention relates to a pressure-sensitive adhesive tape substrate obtained by laminating a polyolefin-based resin by extrusion coating on at least one surface of a base fabric using a polyolefin-based multifilament as a warp and a cross-linked polyolefin-based multifilament as a weft. About.

 Hereinafter, the present invention will be described in detail.

The polyolefin constituting the polyolefin-based methyl filament used in the present invention is an olefin homopolymer such as polyethylene or polypropylene, or an ethylene-α-olefin copolymer, and has a density of 0.900 to 0.970 g / cm ^3. Are preferred. These polyolefins may be used alone or as a mixture. The thickness of the multifilament is preferably 1 to 10 denier monofilament having a total fineness of 30 to 500 denier.

It is preferable to use the same type of polyolefin-based methyl filament for each of the warp and the weft, but there is no particular limitation, and different types of filaments may be used.

The cross-linking method of the cross-linked polyolefin-based multifilament used as the weft is not particularly limited, and a generally used method may be used. That is,
After forming the multifilament, a method of cross-linking by irradiating radiation, electron beam or the like, or dispersing a cross-linking agent such as an organic peroxide in the polyolefin in advance, heating the multifilament, and then heating Crosslinking methods and the like can be mentioned. In this way, by using a polyolefin cross-linked to a weft, a material having better strength and heat resistance than a warp can be obtained. A substrate will be obtained. The degree of crosslinking of the crosslinked multifilament is expressed as an insoluble content (evaluated as a gel fraction) when extracted with hot xylene, and the gel fraction is preferably in the range of 10 to 90%. If the gel fraction is less than 10%, no improvement in strength is observed. Further, if it exceeds 90%, the strength is undesirably reduced.

The polyolefin-based multifilament is produced by a conventional method, and the number of the filaments is preferably in the range of 30 to 130 filaments / inch.

A polyolefin resin is extrusion-coated on at least one surface of the base fabric thus obtained by extrusion coating.
It is laminated with a thickness of μm. Here, the polyolefin resin to be laminated refers to a resin in the same range as the resin used for the multifilament.

The purpose of laminating the polyolefin resin is to make the surface of the base fabric smooth and improve the appearance, to facilitate the application of the pressure-sensitive adhesive, to prevent the escape of the multifilament, and to further impart hand-cutting properties. And the like.
Among these effects, multifilament escape prevention,
In order to develop the hand-cutting property, it is essential that the adhesiveness between the base fabric and the laminated material is good. Therefore, extrusion coating is optimal as a lamination method. That is, it is considered that since the extrusion coating allows lamination at a high temperature, the surface of the multifilament forming the laminated resin and the base fabric is melted and integrated, so that the above-described effect is exhibited. In addition, a method of corona-treating the base fabric in advance for the purpose of further improving the adhesiveness is generally employed.

The processing temperature at the time of extrusion coating is preferably from 270 to 330 ° C. If the temperature is lower than 270 ° C., the adhesion between the laminated polyolefin and the multifilament is insufficient, which is not preferable. On the other hand, when the temperature exceeds 330 ° C., the multifilament partially shrinks and the smoothness deteriorates, which is not preferable.

〔Example〕

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

Example 1 A multifilament having a total fineness of 70 denier was obtained using high density polyethylene monofilament having a thickness of 7 denier and a density of 0.950 g / cm ³ . This multifilament is
Irradiation with Megarad Cobalt 60 gave a crosslinked multifilament. Uncrosslinked multifilaments were used as warp yarns and crosslinked multifilaments were used as wefts to prepare high-density polyethylene woven fabrics each having a driving count of 40 yarns / inch.

Next, low-density polyethylene having a density of 0.924 g / cm ³ was laminated on one surface of the woven fabric by extrusion coating at a processing temperature of 310 ° C. to a thickness of 30 μm to obtain a tape base material. Table 1 shows the results of the evaluation as a tape.

Example 2 Density of 0.939 g / cm ³ as polyolefin resin to be laminated
A tape substrate was obtained in the same manner as in Example 1 except that high-density polyethylene was used. First evaluation result as tape
It is shown in the table.

Example 3 Density 0.928 g / cm ³ as polyolefin resin to be laminated
A tape base material was obtained in the same manner as in Example 1 except that the ethylene-α-olefin copolymer was used. Table 1 shows the results of the evaluation as a tape.

Comparative Example 1 A tape base was obtained in the same manner as in Example 1 except that the uncrosslinked multifilament of Example 1 was used for both warp yarns. Table 1 shows the results of the evaluation as a tape.

Comparative Example 2 A tape base was obtained in the same manner as in Example 1 except that the uncrosslinked multifilament of Example 1 was used, and the warp was set to a total fineness of 50 denier and the number of threads was 50 / inch. Table 1 shows the results of the evaluation as a tape.

[Effects of the Invention] According to the present invention, despite the use of the same denier filament for both the warp and the weft, the weft is crosslinked, so that it has excellent hand-cutting properties, and also has excellent smoothness. In addition, since the materials to be laminated with the filaments are also the same kind, they have excellent adhesiveness, and can be said to be excellent tape base materials which have solved the problems of the conventional adhesive tapes.

Claims (1)

(57) [Claims] 1. A substrate for an adhesive tape, wherein a polyolefin resin is laminated by extrusion coating on at least one surface of a base fabric comprising a polyolefin multifilament as a warp and a crosslinked polyolefin multifilament as a weft. .