JPS60110776A - Production of pressure-sensitive adhesive tape - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive adhesive tape which can be cut in its traverse direction by the hand and has a sufficient tensile strength in the longitudinal direction, by weaving a warp and a weft composed of flat yarn made of a thermoplastic resin into a base close with a difference in the thread count of the warp and the weft and processing the cloth in a specified manner. CONSTITUTION:A base cloth 1 for a tape is woven out of a warp 2 and a weft 3 composed of flat yarn made of a thermoplastic resin by using the warp 2 having lower denier than that of the weft 3 and using the warp 2 with a thread count higher than that of the weft 3. One side of the base cloth 1 is subjected to a corona discharge treatment and a thermoplastic resin is laminated onto the treated surface of the cloth by extrusion to deposit a first laminate layer 4 thereon. The surface of the laminate layer 4 is subjected to a corona discharge treatment and the thermoplastic resin of the same quality is laminated onto the treated surface by extrusion to deposit a second laminate layer 5 thereon. The back of the base cloth is then subjected to a corona discharge treatment and then coated with a pressure-sensitive adhesive to form an adhesive layer 6, thus obtaining a pressure-sensitive adhesive tape. In this way, a tape can be obtd. which can be easily cut in the traverse direction by hand without using scissors and has a sufficient tensile strength in the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an adhesive tape in which a pressure-sensitive adhesive is attached to a base fabric woven from flat yarns made of thermoplastic resin. This invention relates to a method of manufacturing adhesive tape used as packaging material that can be cut.

Conventionally, as an example of this type of tape,
The one disclosed in Publication No. 362 is known. The adhesive tape described in the publication has a base fabric woven with flat yarns made of thermoplastic resin, particularly polyalkylene, a laminate layer of the same material as the above-mentioned material is attached to one side of the base fabric, and a pressure-sensitive adhesive is applied to the other side. In addition, the structure of the base fabric is formed so that the tear strength in the weft direction is lower than that in the warp direction. A method of mixing and heating the laminate to degrade the warp threads.

A method in which the draw ratio of warp yarns is smaller than that of weft yarns. Alternatively, the folding density of the warp yarns is made smaller than the density of the weft yarns. Alternatively, a method has been proposed in which the Denny μ numbers for each prefecture are entered with considerable differences. It is true that the adhesive tape formed by the above-mentioned method has a lower tear strength in the weft direction and can be cut with one hand, but at the same time, the tear strength in the warp direction also decreases, making it difficult to cut 1 strength. The packaging material was insufficient.

An object of the present invention is to form the tape to a tear strength that can be easily cut by hand without using scissors or cutters in the weft direction.

It is an object of the present invention to provide a method for producing an adhesive tape that can be finished into a product that can sufficiently ensure tensile strength in the warp direction of the tape.

The method for producing an adhesive tape according to the present invention is based on Polyglopi V
7 or by weaving flat yarns molded from thermoplastic resin such as polyethylene resin to obtain the base fabric of the tape: Comparing the warp and weft, the thickness of the warp is made thinner, the implantation density is increased, and the weft is made thicker. The weave is thick and the weaving density is low. The above-mentioned base fabric is processed in three steps to produce a product, and the first step is

One side of the base fabric is activated by corona discharge treatment, and extrusion lamination is applied to the treated side with a resin of the same quality as the flat yarn of the base fabric to adhere a single layer of lamiki. A second step is added after cooling the laminate layer. Second
As in the first step, the attached laminate layer is subjected to a corona discharge treatment and then extrusion laminated to form a double laminate layer. The third step is to apply a pressure sensitive adhesive to one side of the base fabric opposite to the above.

By the way, when the extrusion lamination process of the first step is performed, the flat yarn is deteriorated by the heat, but since the warp yarn is thin, the deterioration rate is synergistically greater than that of the weft yarn. If this continues, the tear strength of the tape in the weft direction will decrease, and the tensile strength in the warp direction will also decrease at the same time. Therefore, research has been conducted to increase the tensile strength in the warp direction by changing the structure of the base fabric in various ways. However, strengthening the warp direction also increases the strength in the weft direction, making it difficult to resolve contradictory techniques. However, as a result of repeated research, the inventor conducted an experiment in which the warp threads were made thinner but the stitching density was increased, and the second step was performed in addition to the first step as described above. As a result, by performing extrusion lamination processing in the second step, the laminate layer provided in the first step is softened by the heat of the molten metal, and the resin of the laminate layer is applied to the gaps between the warp and warp threads of the base fabric. It moves in and exerts an anchoring effect, strengthening the binding force of the warp and warp threads and further strengthening the immobilization of each prefecture. Furthermore, when extrusion lamination is performed in the second step, the yarn will naturally deteriorate due to the heat, but the tensile strength in the warp direction will depend on the total thickness of the laminated layer obtained in the first and second steps. This is to support the Therefore, the tensile strength in the warp direction of the tape was maintained at a level sufficient for practical use due to the warp threads being thin but with a high implant density and the overall thickness of the laminate layer. However, even if the laminate layer is formed all at once to the above-mentioned total thickness, the desired product cannot be obtained, so by performing the lamination process in two parts as described above, the weft and warp yarns of 1#4J are Immobilization is further promoted than in the case of one-time immobilization.

When the tape is manually torn in the weft direction, the tearing force prevents the warp threads from escaping in the tearing direction.

All of the tearing force is now applied to the warp threads, and experiments have shown that it is possible to tear easily by hand.

This invention will be explained below with reference to Examples.

As shown in FIG. 1, a tape-shaped base fabric (1) is formed.

The warp (2) and weft (3) are polypropylene flat yarns, which are woven in a plain weave structure with the values shown in Table 1 below.

Table-1 Denier Embossing Density Warp Thread 115 46 wood/inch Weft Thread 320 16/inch
Range of 60 threads/inch, wefts from 2'OO to 400 denier.

A range of 12 to 25 lines/inch was able to achieve the object of the present invention.

A base fabric (1) having the structure shown in Table I is subjected to a first step, a second step, and a third step to form the base fabric.

After corona discharge treatment is applied to one side of the base fabric (1), that side is coated with molten polypropylene heated to 300 to 310°C to a thickness of about 50μ by extrusion lamination, and then cooled to form a fabric as shown in Figure 2. A 1N laminate layer (4) is deposited as shown.

Second step: The surface of the first laminate layer (4) is subjected to corona discharge treatment, and the second M laminate layer (5) is formed by extrusion lamination to form a layer with a thickness of about 20 mm as shown in Figure 3.
Laminate with a thickness of μ 〇 Third step: On the side where the warp yarns (2) (3) are exposed, on the side opposite to the side on which the laminated layers (4) (5) of the base fabric (1) are provided, corona After the discharge treatment, an adhesive layer (6) coated with a pressure-sensitive adhesive as shown in FIG. 4 is attached.

As a result of strength testing of the product obtained in the above process, the values shown in Table H below were obtained.

Table - ■ Tensile strength (KQ15cIR) Longitudinal direction 33.8 39.0 39.4 Latitude direction 47,
655.2 54,9 Tensile elongation (%) Longitudinal direction 10.8 10.2 10.0 Latitude direction 10.
6 10.5 10.2 Tear strength (K9) Latitude direction 2,33 1,62 1.58 In the above table - ■, the tear strength at the time the first laminate layer was attached was as high as 2.33 Kg. It is difficult to tear it with 5 hands. However, by adding two laminated layers, the layer thickness increases, but the fixation between each yarn is high, and 1.58 to 9
The tearing force was halved and it could be easily cut by hand. Incidentally, even if you try to tear the tape in the warp direction, you cannot do it by hand; tests have shown that the tearing force required is three to four times that in the weft direction.

Therefore, it has been demonstrated that the tensile strength in the warp direction can be sufficiently increased.

As described above, according to the method for manufacturing an adhesive tape according to the present invention, the warp of the base fabric woven with flat yarns of thermoplastic resin is formed with a lower denier and higher implant density than the weft, and the base fabric is One side of the base fabric is activated and extrusion lamination is applied to that side twice, and then the other side of the base fabric is activated and then a pressure-sensitive adhesive is applied. Combined with the fabric structure and double extrusion lamination process, we have succeeded in increasing the tape's tensile strength in the warp direction while reducing its tear strength in the weft direction.

It can be fully used as a packaging material for heavy items, and can be easily cut to the required length by hand. Furthermore, since the process of the present invention is simple and can be manufactured using dovetails, conventional weaving machines, and extrusion laminating machines, tapes of various widths can be provided at low cost.

[Brief explanation of the drawing]

The drawings show the process order of the method for manufacturing an adhesive tape according to the present invention, and FIG. 1 is a perspective view showing a woven base fabric, and FIG.
The figure is an enlarged sectional view showing the state in which the first laminate layer is attached to the base fabric, Figure 3 is an enlarged sectional view showing the state in which the 2N laminate layer is attached, and Figure 4 is the commercialized adhesive tape. FIG. (1) Base fabric, (2) Warp, (3) Weft, (
4) (5)...Laminate layer, (6)...Adhesive layer

Claims (1)

[Claims] The base fabric of the tape is woven with warp and warp yarns made of flat yarns made of thermoplastic resin, and the warp yarns have a lower density p than the weft yarns and have a higher folding density than the weft yarns. After applying corona discharge treatment to one side of the base fabric, heat is applied to that side! The first laminate layer is attached by extrusion lamination using a plastic resin, the surface of the first laminate layer is then subjected to corona discharge treatment, and then the second laminate layer is formed by extrusion lamination using the same resin. A method for producing an adhesive tape, in which a pressure-sensitive adhesive is applied after applying a corona discharge treatment to the opposite side of the base fabric to the one side.