JP2006188713A - Pressure-sensitive adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive tape that is produced by using an orthogonal nonwoven fabric and has good weft tearing property. <P>SOLUTION: Filament nonwoven fabric produced by melt-spinning a thermoplastic resin is monoaxially drawn to form a monoaxially oriented, at least one layer nonwoven fabric comprising fibers arranged almost in one direction as the warp and filament nonwoven fabric produced by melt-spinning a thermoplastic resin is monoaxially drawn to form a monoaxially oriented, at least one layer nonwoven fabric comprising fibers arranged almost in one direction as the weft. These base materials are laminated by embossing to prepare the orthogonal nonwoven fabric. In this case, the thickness of the fiber constituting the monoaxially oriented nonwoven fabric for the warp base material is less than 1 denier and the strength of the whole nonwoven fabric for the warp base material is more than 1 g/denier and a pressure-sensitive adhesive layer is formed on one face of the base fabric. The weft tear strength of the adhesive tape is less than 290 grams. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a horizontal tearable adhesive tape used for packaging and the like, and more specifically, a vertically stretched nonwoven fabric spun from a thermoplastic resin is used as a vertical base material, and the horizontal base material and the adhesive tape are used. The present invention relates to a pressure-sensitive adhesive tape having a horizontal tear property formed by laminating a layer and a release layer.
The vertical base material and the horizontal base material refer to base materials in which the fiber orientation direction is parallel and perpendicular to the tape length direction, respectively.

  Conventionally, in the field of pressure-sensitive adhesive tapes, fabrics made of spun yarn mainly made of rayon sufu or cotton have been used as the base fabric. However, these spun yarns are low in strength, have a problem that the strength decreases or swells when wet, and it has been difficult to produce a thin adhesive tape that has been particularly demanded in recent years. In terms of economics, rayon sufu and cotton are not suitable as raw materials for industrial materials that require a stable supply, such as adhesive tape, due to the significant fluctuations in prices due to the market price. Therefore, fabric adhesive base fabrics using long fiber filaments of vinylon and polyester have been studied. However, these synthetic fiber fabrics are inferior in lateral tearability, and in order to improve them, it is necessary to closely weave thin yarns. (Japanese Unexamined Patent Publication Nos. 58-91845, 60-71735, 63-306037, 5-44135, etc.), the cost for the weaving is high, and the quality and economy are inferior. , Not yet completely replaced with Rayon Sukh. Similarly, there are polyolefin flat yarns as raw materials (No. 2-3821, etc.), but they have low horizontal tearing properties, and it is necessary to weave fine yarns closely, resulting in high costs and high quality and economy. Similarly, it is inferior, and since polyolefin is used as a raw material, the lack of heat resistance is also a drawback.

In addition, with the development of automated machines such as automatic packing machines in recent years, the processing speed of the machines has increased, and the frequency of replacement of the used adhesive tape is several times an hour, so the adhesive tape is made thinner. Thus, it has been demanded to increase the winding length of a tape even for a roll having the same diameter. However, since the yarn is bent in the woven fabric, it has been difficult to make it thin.
The present applicants have developed and commercialized various types of orthogonal nonwoven fabrics in which a vertical array nonwoven fabric having high strength in the vertical direction and a horizontal array nonwoven fabric having high strength in the horizontal direction are laminated (Japanese Patent Publication No. 49- 48580, JP-B-50-40185, JP-B 53-38783, JP-B 55-51058, JP-B 57-30368, JP-B 57-54581, JP-B 62-28226, JP-B 1-60408 No., Japanese Patent Publication No. 3-36948, etc.). These orthogonal nonwoven fabrics have also been applied to pressure-sensitive adhesive tapes (Japanese Patent Laid-Open Nos. 58-106737 and 1-204983). The present invention is a further improvement and development of these.
JP 58-91845 A JP-A-60-71735 JP 63-306037 A Japanese Patent Laid-Open No. 5-44135 Japanese Patent Publication No.49-48580 Japanese Patent Publication No. 50-40185 Japanese Patent Publication No.53-38883 Japanese Patent Publication No.55-51058 Japanese Patent Publication No.57-30368 Japanese Patent Publication No.57-54581 Japanese Patent Publication No.62-28226 Japanese Patent Publication No. 1-60408 Japanese Patent Publication No. 3-36948 JP 58-106737 A JP-A-1-204983 Japanese Utility Model Publication 2-3821

The orthogonal nonwoven fabric is manufactured by a method in which a vertical array nonwoven fabric and a horizontal array nonwoven fabric are laminated, and has a productivity of 40 m / min to 100 m / min. On the other hand, in the fabric of the adhesive tape base fabric, it is necessary to make a dense fabric using a thin yarn in order to improve the horizontal tearability. Therefore, even if a recent innovative loom is used, a productivity of 1 m / min or more is achieved. Have difficulty. That is, the orthogonal nonwoven fabric has a productivity about 100 times that of the fabric for fabric adhesive tape.
In addition, since the horizontal tearing property is obtained by a tearing mechanism in which tearing stress is effectively propagated to the horizontal, in the case of a woven fabric, it is necessary to weave so tightly that the flexibility of the structure is lost. Since the yarn is bent, the strength of the filament cannot be exhibited effectively, and only about 70 to 80% of the strength of the original yarn is used. On the other hand, in the orthogonal nonwoven fabric, since the filament is not bent, the strength of the constituting filament is sufficiently exhibited. Furthermore, in the orthogonal nonwoven fabric, the amount of filaments can be reduced by effectively using the strength of the filaments, and since the filaments are not bent, the thickness of the filament layer is reduced, and as a result, a thin adhesive tape can be obtained. it can.
Although it is an orthogonal nonwoven fabric having such characteristics, when it is used as a base fabric for an adhesive tape, the vertical array nonwoven fabric and the horizontal array nonwoven fabric are independent. Inhibits propagation. Thus, it was necessary to solve the problem of horizontal tearability based on the structure unique to the stretched nonwoven fabric.

Next, the same applies to both woven fabrics and stretched nonwoven fabrics.For example, when rayon sufu or polyester is used as a base fabric material, in order to increase the adhesiveness with extruded lamination polyethylene that is often used as a release layer, It is necessary to treat with an adhesive dissolved in an organic solvent, which is called anchor treatment. As the anchor treatment agent, a toluene solution of alkyl titanate is usually used, and other primers such as epoxy, acrylic, polyethyleneimine, and isocyanate are used.
However, this treatment not only costs the adhesive, but also requires a device and a place for effectively removing the exhaust gas of the organic solvent as an environmental measure. There are many problems with safety and environmental friendliness. Another object of the present invention is to provide an adhesive tape that can be produced without using such an anchor treatment agent.

As a result of intensive studies to solve the above problems, the present inventors have found that an excellent pressure-sensitive adhesive tape can be obtained by using a stretched unidirectionally aligned non-woven fabric made of a thermoplastic resin as a vertical base material, thereby completing the present invention. did.
That is, the first aspect of the present invention is a longitudinal unidirectionally aligned non-woven fabric formed by stretching a long-fiber non-woven fabric spun from a thermoplastic resin in one direction and comprising at least one layer in which fibers are arranged in almost one direction. A stretched unidirectional array of non-woven fabrics made from a thermoplastic resin spun from a thermoplastic resin and stretched in one direction. The thickness of fibers constituting the stretched unidirectionally aligned nonwoven fabric of the warp base material is 1 denier or less, and the strength of the entire nonwoven fabric of the warp base material is 1 g / denier or more The present invention relates to an adhesive tape characterized in that an adhesive layer is provided on one side surface of a certain base fabric, and the tear strength in the horizontal direction is 290 g or less. The stretched unidirectionally aligned nonwoven fabric is very suitable as a vertical base material for tape.
A second aspect of the present invention relates to the pressure-sensitive adhesive tape according to the first aspect of the invention, wherein the vertical base material and the horizontal base material are embossed with an embossing pattern including a linear component in the horizontal direction. With this configuration, it is possible to obtain a pressure-sensitive adhesive tape having good transverse tearability.
According to a third aspect of the present invention, there is provided the pressure-sensitive adhesive tape according to the first or second aspect, wherein a synthetic resin layer is provided on at least the other side surface of the base fabric.

According to the present invention, an adhesive tape having good transverse tearability is provided by using an array of filaments of 1 denier or less obtained by stretching the nonwoven fabric, taking advantage of the characteristics of an orthogonal nonwoven fabric that provides high productivity and a thin product. It became possible to do.
Moreover, the adhesive tape by the polyester base fabric requested | required for having the characteristics, such as wet strength and heat resistance, was realizable at low cost.
In addition, it is possible to combine with a horizontal stretched film, to make a reactive acrylic adhesive layer also serve as a release layer, and to eliminate the need for an anchor treatment of an organic solvent by using a hot melt adhesive. In addition, cost reduction and product thickness reduction could be realized.

Further, the present invention will be described in detail.
In the present invention, in order to improve the horizontal tearing property, as a warp base material of a stretched nonwoven fabric, a long-fiber nonwoven fabric spun from a thermoplastic resin is stretched in one direction, and the fibers are arranged substantially in the above-mentioned one direction. Use non-woven fabric. When thin filaments of 1 denier or less are juxtaposed, the horizontal tear stress breaks each filament into individual pieces, so that the tear propagates with a small tear stress.
In a normal woven fabric, tearing is difficult because the tear stress acts on the yarn which is a bundle of filaments. The prior invention (JP-A-60-71735, etc.) describes that weaving is substantially untwisted, but the woven fabric is composed of untwisted yarn, particularly filaments of 1 denier or less. Yarns are difficult to handle because of poor productivity, and are less effective because twisting occurs during the weaving process.

  In the present invention, in place of the unidirectionally stretched nonwoven fabric, it is also possible to use a warped non-twisted yarn as a vertical base material. However, it is difficult to warp a fine yarn composed of fine filaments of 1 denier or less, and the production speed is also reduced. Therefore, the present inventors previously invented an invention in which a nonwoven fabric obtained by stretching a continuous web of spun and accumulated webs in a vertical direction is used as a vertical base material (Japanese Patent Publication Nos. 3-36948 and 7-6126). Each publication). According to this method, a filament of 2 to 3 denier is spun at the spinning stage in the same manner as a normal non-woven fabric, but the filament is made to be 1 denier or less by stretching it 5 to 8 times in the vertical direction. In this case, in the spinning stage, the filaments are unoriented, and the accumulated webs are arranged in the vertical direction, so that the stretching in the vertical direction and the strength after the stretching can be improved. However, since the vertical alignment of the filaments of the integrated web at the spinning stage is not complete, the drawn filaments are slightly mixed with unstretched filaments and unaligned filaments, and are mainly composed of a vertical group consisting of filaments of 1 denier or less. Become a material. These unstretched filaments have a low melting point, and are melted by subsequent stretching or heat treatment to perform the adhesive function of the filament in the vertical base material, and have the effect of reducing the flexibility of the filament and improving the horizontal tearability.

The warp-oriented nonwoven fabric obtained as described above has a strength of 1 g or more per denier (hereinafter referred to as “d”), preferably 1.5 g / d or more, and more preferably 2 g / d or more. It is desirable. If it is less than 1.5 g / d, the alignment and stretching are insufficient, so that the rubber elasticity remains in the filament, the tearability is lowered, and the strength is small, so that it is unsuitable as a vertical base material for the adhesive tape.
Most of the individual filaments of the vertical stretch nonwoven fabric in the present invention have a strength of 3 g / d to 5 g / d. However, since various filaments are mixed and complicated, the strength is indicated by the strength of the web of the vertical base material. It was decided to. In addition, although the method of displaying the strength of the web in kilograms per square millimeter is general, the vertical base material used in the present invention is an aggregate of filaments, and the cross-sectional shape changes depending on the pressure and is not constant. Displayed in g / d. That is, 10 test pieces having a width of 50 mm and a length of 300 mm were cut out from the vertical base material, and after measuring the thickness (d), measurement was performed at a chuck interval of 100 mm and a tensile rate of 100% / min, and the average value ( g / d).
As a method for producing a nonwoven fabric composed of filaments of 1d or less, the melt-blowing method is a well-known method. However, in the melt-blown nonwoven fabric, the filaments are not arranged vertically, and the strength in the longitudinal direction of the nonwoven fabric is extremely low. 3 g / d or less.

  As the spinning means of the vertical base material of the present invention, conjugate spinning and mixed spinning consisting of different polymers of an adhesive polymer and a normal polymer in the inventors' prior invention (PCT WO96 / 17121) are particularly suitable. Yes. This is because the filaments of the vertical base material are bonded and fixed by these adhesive polymer components, and the horizontal tearing property is increased by improving the adhesiveness to the horizontal base material.

  As the horizontal base material used in the present invention, the present invention of the present inventors (Japanese Patent Publication No. 3-36948, Japanese Patent Publication No. 7-6126, Japanese Patent Application Laid-Open No. Hei 2-269859) is spun and accumulated. A horizontal stretch nonwoven fabric made of filaments obtained by stretching a continuous web in the horizontal direction is used. This is because it is thin and flexible, has a cloth-like feel, and can impart a high-class feeling.

The polymer used for the vertical base material and the horizontal base material of the present invention is used as a flat yarn or an industrial material fiber such as high-density polyethylene, polyolefin such as polypropylene, nylon, polyester, polyvinyl alcohol, polyacrylonitrile or the like. A polymer is used. In particular, polypropylene and polyester are excellent in terms of cost and handling.
One feature of the present invention resides in the practical application of polyester that has been strongly demanded in the past in terms of wet strength, heat resistance and cost.

Another important problem to be solved by the present invention is to restrain the movement of the filament in the vertical base material and firmly fix it to the horizontal base material. If it is not firmly fixed, when the horizontal tear stress acts on the filament in the vertical substrate, the latter filament will escape, so cut the thin filament of the vertical substrate individually and cut with a small tear stress Therefore, a large tear stress is required. In the case of woven fabrics, the interlacing of closely woven yarns plays a role in restraining the yarn movement.
As a bonding method for the stretched nonwoven fabric of the present invention, heat embossing adhesion is used. The heat emboss bonding is a method in which a convex portion heated to a temperature equal to or higher than the softening point of the filament is pressed against the adherend and thermocompression bonded. The shape of the convex portion can be variously selected depending on the intended use and adhesive strength. The present inventors have found that an embossed pattern having a linear component in the horizontal direction increases the horizontal tearability.
An ultrasonic bonding method in which an ultrasonic horn is brought into contact with the embossed pattern on the basis of the same principle as that of hot embossing can also be used. These are collectively referred to as an embossing process.

The present inventors have also found that various adhesives are effective as a method for joining a vertical base material and a horizontal base material. The adhesive not only effectively bonds the vertical base material and the horizontal base material, but also is filled between the filaments of the vertical base material to reduce the flexibility of the filament and improve the horizontal tearability.
The release layer used in ordinary cloth adhesive tape is low-density polyethylene formed by extrusion lamination, and as an anchor treatment that provides adhesion between the polyethylene and the base cloth or polyester cloth, Although it is necessary to treat the surface of the fabric with a toluene solution of alkyl titanate, the adhesive in the present invention can serve as this anchor treatment. Furthermore, in the case of reactive adhesives, there are those that exhibit releasability after reaction, in which case the adhesive layer after reaction functions as a release layer, and there is no need to provide a new release layer. .
As described above, the use of the adhesive makes it possible to omit the anchoring process and the step of providing the release layer, so that there is a great merit from the viewpoint of simplifying the process and improving the economy.
As the adhesive, various types such as an emulsion type, a solvent type, a powder type, a fiber type, a hot melt type, and a UV curable type can be used.

As described above, in the present invention, the adhesiveness between the vertical base material and the horizontal base material is important, but in order to enhance the adhesiveness, the present inventors apply a corona discharge treatment to the vertical stretch nonwoven fabric. Has been found to be particularly effective. The effect is particularly remarkable when the vertically stretched nonwoven fabric is made of polyester filaments. This seems to be due to the fact that the filament base material has a small filament diameter and a large surface area.
The corona discharge treatment can be replaced by plasma treatment, flame treatment, or the like having the same effect, but these are collectively referred to as corona discharge treatment.

  As the pressure-sensitive adhesive layer used in the present invention, various pressure-sensitive adhesives such as natural rubber, synthetic rubber, acrylic and hot melt can be used. When a thin adhesive layer is required, an acrylic adhesive that is thin and has high adhesive strength is selected.

Hereinafter, specific examples of the present invention will be described in detail.
<Example 1>
Based on FIG. 1, the example of the manufacturing method of the vertical base material of this invention is demonstrated (Japanese Patent Publication Nos. 3-36948, 7-6126, etc.).
Polyester resin (manufactured by Unitika Co., Ltd .: IV value 0.65, melting point 255 ° C.) is melt kneaded by the extruder 2 and quantitatively extruded by the gear pump 3 as a raw material resin 1 and melt blow die together with hot air from the hot air generator 4 5 was spun into a filament shape.
The spun filament 6 is accumulated on an inclined conveyor 7 to form a laminated web 8 and is wound by a winder 9.
The wound laminated web 8 was stretched 5.8 times between rolls (not shown) to form a vertical base material. When the thickness of the filament constituting the vertical base material was calculated by a photograph and converted, it was a size centered on 0.3 denier. Further, the strength of the web obtained by stretching was 2.2 g / d.

Based on FIG. 2, an example of a method for producing a horizontal substrate according to the present invention will be described (Japanese Patent Publication No. 3-36948 and Japanese Patent Laid-Open No. Hei 2-242960).
A polyester resin (manufactured by Unitika Co., Ltd .: IV value 0.60) was melt-kneaded by an extruder 22 and quantitatively extruded by a gear pump 23 as a raw material resin 21 and led to spray nozzles 24-1 to 24-6. The spinning filaments 25 exiting from the nozzles are scattered in a horizontal direction with respect to the traveling direction by the action of hot air (not shown) to form a laminated web 27 of filaments arranged in a horizontal manner on a conveyor 26, and a winder 28. Rolled up.
The wound side-by-side laminated web 27 was stretched 5.6 times in the transverse direction by a transverse stretching apparatus shown in Japanese Patent Publication No. 3-36948 to obtain a transverse base material.

The vertical base material and the horizontal base material obtained above are heat-sealed by an embossing apparatus shown in FIG.
The warp base material 31 and the horizontal base material 32 were guided to nip rolls 33a and 33b, embossed between the embossing roll 34a and the receiving roll 34b heated to 220 ° C., and taken up by the nip rolls 35a and 35b to obtain an orthogonal nonwoven fabric 36.
4A to 4D are examples of embossed patterns. In Example 1, the pattern shown in FIG. That is, a line having a length of 1.25 mm and a width of 0.35 mm is arranged in a staggered pattern with a pitch of 1.25 mm.
The orthogonal nonwoven fabric 36 is anchored with a toluene solution of an alkyl titanate, subjected to extrusion lamination of low density polyethylene on the vertical base material side to form a release layer, and an adhesive layer is applied to the horizontal base material side to obtain an adhesive tape. .

Table 1 shows the physical properties of the pressure-sensitive adhesive tape produced by the above method.
In the table, PET is an abbreviation for polyester, PE is polyethylene, PP is polypropylene, and HDPE is high-density polyethylene.
Further, the strength of the adhesive tape was shown only in the vertical direction, and the measurement was performed at a chuck distance of 50 mm and a tensile speed of 100 mm / min. The tear strength is measured by an Elmendorf-type tear tester according to JIS L1096, and only the tear strength in the horizontal direction is shown.
In addition, when the emboss pattern which does not contain a linear component in a horizontal direction like FIG.4 (C) and FIG.4 (D) was used, it turned out that it is inferior to the linearity of tearing.

<Example 2-1>
A web 8 having a basis weight of 2/3 of Example 1 was produced by spinning in the same manner as in Example 1, and separately a polyester resin having a melting point of 225 ° C. (manufactured by Unitika Ltd .: IV value 0.65). To produce a web 8 ′ having a basis weight of 1/3 of that of Example 1, stretching the web 8 and the web 8 ′ in layers, and stretching the thickness after stretching. A vertical substrate of 0.7 denier was obtained.
Next, in the same manner as in Example 1, the web 8 ′ was laminated using a horizontal base material, and after embossing, a release layer and an adhesive layer were provided to obtain an adhesive tape. The results are shown in Table 1. In this case, the tearability is better than that of Example 1.

<Example 2-2>
Except for not using a horizontal base material, other than that, an adhesive tape was obtained in the same manner as in Example 2-1. The results are shown in Table 1. This example is an experimental example outside the scope of the claims of the present application.

<Example 3-1>
A vertical base material and a horizontal base material obtained in the same manner as in Example 1 were layered, and a water-soluble urethane (trade name: Super Frec E2000, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and an ethylene-vinyl acetate copolymer emulsion ( (Product name: Sumikaflex 471, manufactured by Sumitomo Chemical Co., Ltd.) and then squeezed so that the solid content of the adhesive is 28% by weight with respect to the total weight. Drying heat treatment was performed. Next, after corona treatment was applied to the vertical base material side, extrusion lamination of low density polyethylene was performed, and an adhesive was applied to the horizontal base material side to obtain an adhesive tape. The results are shown in Table 1.
The obtained adhesive tape had good transverse tearability. In addition, a present Example is the experiment example which performed the background lamination | stacking with the adhesive agent, and is outside a claim of this application.

<Example 3-2>
In Example 3-1, after drying the adhesive, an embossing process using the pattern of FIG. 4B was performed, and thereafter, the same process as in Example 3-1 was performed. The results are shown in Table 1.
By the embossing treatment, the horizontal tearing property of the adhesive tape was improved, and a cloth-like feel was imparted to give a high-class feeling.

<Example 4>
The warp base material and the horizontal base material obtained in the same manner as in Example 1 were each subjected to corona treatment and then overlapped and dipped in a reactive acrylic emulsion (trade name: Dicknal E8300K, manufactured by Dainippon Ink & Chemicals, Inc.). Thereafter, the adhesive was squeezed so that the solid content of the adhesive was 38% by weight with respect to the total weight, and dried on a hot cylinder. Drying is performed at a low temperature of around 100 ° C., and an adhesive layer is applied to the side of the horizontal base material in a state where the reaction of the acrylic adhesive has hardly progressed, and an acrylic polymerization reaction is performed by heating (155 ° C.) in the coating process. Made progress. In the pressure-sensitive adhesive tape thus obtained, the acrylic adhesive after the reaction on the side of the vertical substrate can serve as a release layer without providing a release layer. The results are shown in Table 1. In addition, a present Example is the experiment example which performed the background lamination | stacking with the adhesive agent, and is outside a claim of this application.

<Example 5>
A tape having a thickness of 52 μm and a width of 6 mm made of a polyester film (manufactured by Unitika Ltd .: IV value 0.72) was stretched and heat-treated to form a 340d flat yarn. A unidirectional array was produced from this flat yarn using hot melt (trade name: Byron 300, manufactured by Toyobo Co., Ltd.) according to the method described in JP-B-59-6943. A vertical base material obtained in the same manner as in Example 1 was laminated in the manner described in Japanese Patent Publication No. 53-38783. Since the above hot melt adhesive also adheres to the vertical base material on the cylinder in the process of laminating and bonding process, it was possible to perform a low density polyethylene release layer application treatment without using an anchor treatment agent. Next, an adhesive layer was provided on the side of the horizontal substrate to obtain an adhesive tape. The results are shown in Table 1. In addition, a present Example is a test example outside the scope of the claims of the present application, in which background lamination was performed using a hot melt adhesive.

<Example 6>
After the corona treatment was applied to the warp base material obtained in the same manner as in Example 1, an ethylene-vinyl acetate hot melt adhesive (trade name: Q2375J4, manufactured by Henkel Hakusui Co., Ltd.) was applied to the substrate. A horizontal stretched film made of density polyethylene (thickness 25 μm, trade name: Callarian, manufactured by Toyo Chemical Co., Ltd.) was laminated and adhered, and then an adhesive was applied to the vertical substrate side to obtain an adhesive tape. In this case, the horizontal stretched film serves as a release layer. The results are shown in Table 1. In addition, a present Example is a test example outside the scope of the claims of the present application, in which background lamination was performed using a hot melt adhesive.

<Example 7>
Polypropylene conjugated fine denier filaments using straight polypropylene (MFR 32g / 10min) as the core component and modified polypropylene (trade name: Nisseki N Polymer P4070, manufactured by Nippon Petrochemical Co., Ltd.) as the sheath component are spun and drawn. Thus, a yarn having a single yarn thickness of 0.8d and a yarn thickness of 120d was manufactured and warped to 50 pieces / 25 mm to obtain a warp base material.
Separately, a 150-μm-thick three-layer film in which modified polypropylene (same as above) is laminated on both sides of straight polypropylene (MFR 4 g / 10 min), rolled 1.8 times, and then staggered slits are inserted in the horizontal direction. Further, it was stretched 6.5 times in the horizontal direction to obtain a horizontal stretched web. After laminating the warp base material and the horizontal stretched web and bonding them at 147 ° C., extrusion lamination of the modified polypropylene was performed on the side of the vertical base material, and an adhesive was applied to the side of the horizontal stretch web to obtain an adhesive tape. The results are shown in Table 1. In addition, a present Example uses the horizontal extending | stretching web which put the slit in the polypropylene film and extended | stretched as a horizontal base material, and is an experiment example outside the claim of this application.

<Comparative Example 1>
Table 2 shows the measured values of the conventional rayon fabric cloth adhesive tape.

<Comparative example 2>
This was carried out in the same manner as in Example 1 except that a vertical base material having a filament thickness of 2 to 3d was used. The results are shown in Table 2. It can be seen from the table that the tearability is poor.

<Comparative Example 3>
It carried out like Example 1 except having used the length base material whose intensity is 1 g / d or less. The results are shown in Table 2. Also in this case, the tearability was poor.

  According to the present invention, it is possible to provide a pressure-sensitive adhesive tape having good transverse tearability. Moreover, the adhesive tape by the polyester base fabric requested | required for having the characteristics, such as wet strength and heat resistance, can be implement | achieved at low cost.

It is a schematic side view of an example of a vertical substrate manufacturing apparatus. It is a schematic side view of the example of the manufacturing apparatus of a horizontal base material. It is a schematic side view of an example of an embossing device. It is a top view which shows the example of an embossing pattern.

Explanation of symbols

1, 21 Raw material resin 2, 22 Extruder 3, 23 Gear pump 4 Hot air generator 5 Melt blow die 6, 25 Spinning filament 7, 26 Conveyor 8, 27 Laminated web 9, 28 Winder 24-1-6 Nozzle 31 Vertical base Material 32 Horizontal base material 33a, 33b, 35a, 35b Nip roll 34a Emboss roll 34b Receiving roll 36 Embossed orthogonal nonwoven fabric

Claims (3)

A long-fiber non-woven fabric spun from a thermoplastic resin is stretched in one direction, and a stretched unidirectional non-woven fabric consisting of at least one layer in which fibers are arranged in almost one direction is used as a warp base material, and is spun from a thermoplastic resin. It is an orthogonal nonwoven fabric obtained by stretching a unidirectionally stretched nonwoven fabric in which fibers are arranged in one direction and a stretched unidirectionally aligned nonwoven fabric in which fibers are arranged in almost one direction, and laminating these substrates by embossing, An adhesive layer on one side of the base fabric in which the thickness of the fibers constituting the stretched unidirectionally aligned nonwoven fabric of the warp base material is 1 denier or less and the strength of the entire nonwoven fabric of the warp base material is 1 g / denier or more A pressure-sensitive adhesive tape having a transverse tear strength of 290 g or less. The pressure-sensitive adhesive tape according to claim 1, wherein the vertical base material and the horizontal base material are embossed with an emboss pattern including a linear component in the horizontal direction. The pressure-sensitive adhesive tape according to claim 1 or 2, wherein a synthetic resin layer is provided on at least another side surface of the base fabric.

Images