JP6788891B2 - Adhesive tape and manufacturing method of adhesive tape - Google Patents

Description

The present invention relates to an adhesive tape and a method for manufacturing an adhesive tape, and more specifically, an adhesive tape used for masking and curing in building interior / exterior, building painting, vehicle painting, etc., and an adhesive tape used for packaging, etc. As described above, in adhesive tapes that are required to have hand-cutting property, by preventing expansion and contraction of the base material layer and improving tensile strength while maintaining hand-cutting property, misalignment and peeling after sticking, The present invention relates to an adhesive tape capable of preventing deformation of a telescope-like (bamboo child-like) when wound into a roll, and a method for producing the same.

As the adhesive tape used for masking and curing in the above-mentioned interior / exterior of buildings, architectural painting, vehicle painting, etc., a single-sided tape in which an adhesive is applied to one side of a film to be a base material layer is generally used.

As shown in FIG. 5, such an adhesive tape 100 is provided in a state of being rolled into a winding core 140 or the like so that the adhesive layer 130 is on the inside and the base material layer 120 is on the outside. At the time of use, the user pulls out the adhesive tape 100 from the roll for a required length, attaches it to the adherend, and then cuts and attaches it at a desired portion.

When cutting such an adhesive tape 100, it is possible to cut by using a dedicated cutter having a sawtooth-shaped blade, or by using a blade such as scissors or a cutter knife, but such a blade or the like each time it is cut. In order to avoid the complexity of using the adhesive tape, there is a demand for an adhesive tape having "hand-cutting property" that can be easily cut by hand.

Adhesive tapes having such hand-cutting properties include Japanese paper, textile fabrics (hereinafter referred to as "split cloth"), and adhesive tapes using an embossed synthetic resin film as a base material. ..

In particular, when the adhesive tape is cut by hand, it is required that the adhesive tape can be cut linearly in a direction orthogonal to the longitudinal direction of the adhesive tape. As an adhesive tape satisfying such a requirement, the base material layer is divided as described above. The so-called "cloth tape" composed of cloth is the mainstream, and a polyolefin-based resin film having a concave groove formed in a direction orthogonal to the longitudinal direction of the adhesive tape to impart hand-cutting property is used as a base material layer. Things are provided.

In the above-mentioned cloth tape, a PE film having a thickness of about 10 to 40 μm is laminated on both sides or one side of a split cloth formed by weaving fibers such as suhu (rayon) or polyester with different thicknesses of warp and weft. Is used as a base layer.

With a cloth tape using a base material layer provided with a split cloth produced by weaving warp threads and weft threads in this way, even when cut by hand, the warp threads or weft threads of the split cloth are cut linearly in the length direction. can do.

However, with such a cloth tape, in order to obtain a base material layer from the above-mentioned structure, a step of laminating a pre-woven split cloth with a PE film is required, resulting in a multi-step manufacturing process. ， Cloth tape is expensive.

Therefore, an adhesive tape has been proposed in which a single-layer synthetic resin film is used as a base material and can be cut linearly in the width direction even when cut by hand.

As such an adhesive tape 100, as shown in FIG. 6, one surface is formed as a smooth surface 121, and a large number of concave grooves 123 are formed on the other surface in a direction orthogonal to the longitudinal direction of the adhesive tape at predetermined intervals. An adhesive tape has been proposed in which a polyolefin resin film having an uneven surface 122 is used as a base material layer 120, and an adhesive is applied to the uneven surface 122 of the base material layer 120 to form an adhesive layer 130 (Patent). Document 1).

Further, as described above, in the adhesive tape 100 using the polyolefin resin film having the uneven surface 122 as the base material layer 120, the structure for reducing the elongation of the adhesive tape 100 in the longitudinal direction while maintaining the hand-cutting property. The adhesive tape 100 provided with the above is also proposed.

As such an adhesive tape 100, as shown in FIG. 7, the adhesive layer 130 formed on the uneven surface 122 of the polyolefin resin film base material layer 120 is formed by the non-woven fabric or the split cloth 135 and the adhesive 131. There is one that has proposed this (Patent Document 2).

Further, as shown in FIG. 8, after applying a polyester resin 136 having a number average molecular weight of 10,000 or more and a glass transition temperature of 0 to 80 ° C. on the uneven surface 122 of the polyolefin resin film base material layer 120. , An adhesive tape in which an adhesive layer 130 is formed by applying an acrylic adhesive is also proposed (Patent Document 3).

Japanese Unexamined Patent Publication No. 3-47885 Japanese Unexamined Patent Publication No. 9-137133 Actual Opening 2001-172586

In the adhesive tape 100 (FIG. 6) introduced as Patent Document 1 described above, a concave groove 123 is formed on the uneven surface 122 of the polyolefin resin film used as the base material layer 120 in a direction orthogonal to the longitudinal direction of the adhesive tape 100. Therefore, even when the adhesive tape 100 is cut by hand, the base material layer 120 can be cut neatly in a straight line by tearing along the concave groove 123.

However, the polyolefin resin film adopted by the adhesive tape 100 described in Patent Document 1 as the base material layer 120 is not only non-stretched and is itself rich in elasticity as compared with paper or split cloth. Since the concave groove 123 is formed in the direction orthogonal to the longitudinal direction of the adhesive tape 100, the base material layer 120 is more easily stretched in the formed portion of the concave groove 123 which is thin.

As a result, in such an adhesive tape 100, when the tape of a required length is pulled out from the state of being wound in a roll shape as shown in FIG. 5, or when the tape is cut by hand, the adhesive tape 100 The base material layer 120 of the above is stretched in the longitudinal direction, and is attached to the adherend in the stretched state in this way.

Then, the adhesive tape 100 attached with the base material layer stretched shrinks in an attempt to return to the original shape of the base material layer 120, so that the attachment position on the adherend shifts with time, or , The end of the adhesive tape 100 is lifted and peeled off, and if such an adhesive tape is used for masking during painting, the coating position will shift.

Further, the polyolefin resin film used as the base material layer 120 in the adhesive tape 100 described in Patent Document 1 is easily stretched in the longitudinal direction as described above, and is heated to 90 to 110 ° C. when the pressure-sensitive adhesive is applied to the base material layer. Since it is heated and dried, it is wound around the winding core 140 in a state of being stretched by about 0.3 to 1% due to the tension when it is subsequently wound into a roll.

As a result, the adhesive tape 100 contracts in the longitudinal direction after being wound into a roll shape, so that the roll of the adhesive tape 100 tends to be deformed into a telescope shape (bamboo shoot shape) as shown in FIG. There is.

On the other hand, if the adhesive tape 100 is wound with low tension in order to prevent such deformation of the telescope shape (bamboo shoot shape), cavities (cavities) are likely to occur due to the entrainment of air, and both of them have a poor appearance. It cannot be shipped as a product, and the defective rate generated in this way reaches a maximum of about 1 to 7%, resulting in poor yield.

Furthermore, with adhesive tapes used for masking or curing, it is necessary to peel off and remove the adhesive tape from the adherend after the work such as painting is completed, but in order to impart hand-cutting property, it is necessary to remove it in the longitudinal direction. The adhesive tape 100 having the polyolefin resin film having the concave groove 123 formed in the direction orthogonal to the substrate layer 120 is easy to stretch and cut even during the work of peeling from the adherend. The peeling work becomes complicated.

As described above, the adhesive tape 100 described in Patent Document 1 in which the polyolefin resin film having the concave groove 123 formed on one side as the base material layer 120 easily stretches in the longitudinal direction, and as a result, the above-mentioned various problems occur. Therefore, it is required to suppress the elongation of the adhesive tape 100 in the longitudinal direction.

As a method of suppressing such elongation, it is conceivable to make the depth of the concave groove 123 shallow or to make the entire polyolefin resin film used as the base material layer 120 thick, but in this configuration, the adhesive tape 100 Although it is possible to suppress elongation in the longitudinal direction, the hand-cutting property of the adhesive tape 100 is reduced, and particularly in a configuration in which the thickness of the entire polyolefin resin film is increased, the followability to the surface of the adherend is reduced. Peeling or the like is likely to occur.

On the other hand, in the adhesive tape (FIG. 7) described in Patent Document 2 described above, the adhesive tape 100 is strengthened by embedding a non-woven fabric or a split cloth 135 in the adhesive layer 130 to strengthen the adhesive layer 130. The occurrence of elongation in the longitudinal direction is suppressed.

However, in this configuration, it is necessary to integrate the non-woven fabric or the split cloth 135 and the adhesive 131 to form the pressure-sensitive adhesive layer 130, and as shown in FIG. 10, the non-woven fabric or the split cloth 135 and the pressure-sensitive adhesive 131 are stepped. Since it is necessary to form the adhesive layer 130 by laminating it on the paper 150 and then laminating it on the polyolefin resin film to be the base material layer 120, it is manufactured in the same manner as in the case of the cloth tape described above. As a result of the increase in the number of steps and the increase in manufacturing cost, the adhesive tape 100 becomes expensive.

Moreover, in the structure in which the non-woven fabric or the split cloth 135 is embedded in the pressure-sensitive adhesive layer 130, the elongation can be suppressed, but the hand-cutting property is significantly reduced.

Moreover, since the deformability of the adhesive layer 130 is significantly reduced by burying the non-woven fabric or the split cloth 135, the followability of the adherend to the surface is lowered, peeling or floating is likely to occur, and the function as a masking tape is provided. It can also be compromised.

Further, as shown in FIG. 8, in the configuration described in Patent Document 3 described above, the polyester resin 136 is applied to the uneven surface 122 provided on the base material layer 120 made of the polyolefin resin film before the adhesive is applied. ， Elongation may be suppressed, but it is considered that the hand-cutting property is significantly reduced or almost lost.

Further, when the polyester resin 136 is applied as the base layer and then the solvent-type pressure-sensitive adhesive is applied to form the pressure-sensitive adhesive layer 130, the base polyester-based resin 136 invades the solvent in the pressure-sensitive adhesive 131. Therefore, the polyester-based resin layer 136 is softened by the so-called "solvent attack" that causes an abnormality, and the effect of suppressing elongation cannot be obtained. Therefore, it is considered that the manufacturing method or the material is also restricted.

Therefore, the present invention has been made to eliminate the above-mentioned drawbacks in the prior art, and as described above, a polyolefin resin film having one surface formed as a smooth surface and the other surface as an uneven surface is used as a base material layer. In an adhesive tape in which an adhesive layer is formed on the uneven surface of the base material layer, the elongation in the longitudinal direction is suppressed while maintaining the hand-cutting property in the width direction of the adhesive tape, specifically, the elongation is 70% or less. , Preferably suppressed to 50% or less, more preferably 30% or less, and the tensile strength was improved, specifically 100 (N / 50 mm width) or more, preferably 130 (N / 50 mm width) or more. By providing the adhesive tape, it is possible to prevent the adhesive tape from being displaced or peeled off after being attached, and to prevent the adhesive tape wound in a roll shape from being deformed into a telescope shape (bamboo child shape) as shown in FIG. Moreover, it is an object of the present invention to provide an adhesive tape and a method for producing an adhesive tape, which have good workability when peeled from an adherend after completion of painting work or the like.

The means for solving the problem are described below together with the reference numerals used in the embodiment of the invention. This reference numeral is described in order to clarify the correspondence between the description of the claims and the description of the form for carrying out the invention. Needless to say, this reference numeral is limited to the interpretation of the technical scope of the present invention. Not used.

In order to achieve the above object, the adhesive tape 10 of the present invention is used.
An unstretched polyolefin resin film base material layer 20 having a concavo-convex surface 22 in which a plurality of concave grooves 23 are formed at predetermined intervals on one surface in a direction orthogonal to the longitudinal direction, and the concavo-convex surface 22 of the base material layer 20. The pressure-sensitive adhesive layer 30 formed above is provided, and the fiber pieces 32 are dispersed in the pressure-sensitive adhesive of the base material layer and / or the pressure-sensitive adhesive layer 30 (claim 1, FIGS. 1 to 1). 3).

In the present invention, the "fiber piece" includes a monofilament composed of a simple substance of a short fiber, a fragment of a short fiber or a long fiber, and a fragment of a multifilament (thread) obtained by twisting a monofilament.

The pressure-sensitive adhesive layer 30 is characterized by containing 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, of the fiber piece 32 with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive 31 (claim). 2, Fig. 1 (A)).

The fiber piece 32 has a fiber diameter of 0.05 to 100 denier (0.01 to 200 μm diameter), preferably 1 to 10 denier (15 to 60 μm), more preferably 0.5 to 4 denier (3 to 40 μm). Can be used (claim 3).

The "denier" is the mass of a 9000 m thread expressed in grams, and the value of 1/9 of the above "denier" is the "tex" (mass of a 1000 m thread) used in JIS and ISO. Is expressed in grams).

Further, the length of the fiber piece 32 can be 1 to 10 mm, preferably 1 to 7 mm, and more preferably 2 to 5 mm (claim 4).

It should be noted that various fiber diameters and fiber lengths can be mixed and used.

Further, the base material layer is characterized by containing 0.2 to 10 parts by weight, preferably 0.5 to 3 parts by weight, of the fiber pieces with respect to 100 parts by weight of the solid content of the base material layer (claimed). Item 5, FIG. 1 (B)).

The adhesive tape 10 of the present invention has an elongation in the longitudinal direction of 30% or less, preferably 20% or less, and more preferably 16% or less (claim 6).

Further, it is preferable that the tensile strength in the longitudinal direction is 100 (N / 50 mm width) or more (claim 7).

The pressure-sensitive adhesive layer 30 of the pressure-sensitive adhesive tape 10 of the present invention may have fiber pieces 32 uniformly dispersed over the entire thickness direction (see FIG. 1A), but is preferably attached to an adherend. It is preferable that the amount of dispersion of the fiber pieces 32 is reduced on the landing side (lower side of the paper surface), or that the fiber pieces 32 are not included (see claims 8, FIGS. 2 and 3).

Further, it is preferable that the pressure-sensitive adhesive layer 30 has a structure in which the amount of dispersion of the fiber pieces 32 is reduced on the side of attachment (upper side of the paper surface) to the base material layer 20 or the fiber pieces 32 are not contained. Claim 9, see FIG. 3).

As the fiber piece 32 to be dispersed in the pressure-sensitive adhesive layer 30, one made of any material selected from the group of acrylic, PET, olefin resin, rayon, vinylon, and nylon can be used, and the fiber piece can be used. One of 32 types, or a mixture of two or more types, may be dispersed in the pressure-sensitive adhesive layer 30 (claim 10).

Further, the method for manufacturing the adhesive tape 10 of the present invention is as follows.
An adhesive is applied to the uneven surface 22 of the base material layer 20 made of an unstretched polyolefin resin film having uneven surfaces 22 having a plurality of concave grooves 23 formed at predetermined intervals on one side in a direction orthogonal to the longitudinal direction. It is characterized in that the pressure-sensitive adhesive layer 30 is formed by laminating, and the fiber pieces 32 are dispersed in the base material layer and / or the pressure-sensitive adhesive layer (claim 11).

In the formation of the pressure-sensitive adhesive layer 30, the dispersion amount of the fiber pieces 32 is reduced on the adhesive surface side with the adherend by laminating a plurality of types of pressure-sensitive adhesives in which the dispersion amount of the fiber pieces 32 is changed in multiple layers. Alternatively, the pressure-sensitive adhesive layer 30 that does not contain the fiber piece 32 may be formed on the adhesive surface side with the adherend (see claim 12, FIGS. 2 and 3).

Similarly, a plurality of types of pressure-sensitive adhesives in which the dispersion amount of the fiber pieces 32 is changed are laminated in multiple layers, and the dispersion amount of the fiber pieces 32 is increased on the adhesive surface side of the base material layer 20 with the uneven surface 22. The amount may be reduced, or the pressure-sensitive adhesive layer 30 containing no fiber pieces may be formed on the adhesive surface side of the base material layer 20 with the uneven surface 22 (see claims 13 and 3).

With the configuration of the present invention described above, the adhesive tape 10 of the present invention could obtain the following remarkable effects.

An unstretched polyolefin resin film having an uneven surface 22 having a concave groove 23 formed on one surface is used as the base material layer 20, and an adhesive 31 is laminated on the uneven surface 22 of the base material layer 20. By forming the pressure-sensitive adhesive layer 30 and dispersing the fiber pieces 32 in the base material layer and / or the pressure-sensitive adhesive layer, adhesiveness with reduced elongation in the longitudinal direction while maintaining hand-cutting property in the width direction. The tape 10 could be obtained.

The suppression of elongation by the dispersion of the fiber pieces behaves as if the base material layer and / or the pressure-sensitive adhesive layer is hypercrosslinked by the dispersion of the fibers (these behavior is exhibited in the present specification). By (the state is called a "pseudo-crosslinked state"), the elongation is physically suppressed, and compared to chemical cross-linking, the functional groups that contribute to the adhesive force are not blocked, and the adhesive force is developed. It is advantageous in that it does not reduce.

As described above, the adhesive tape 10 of the present invention can be stretched less in the longitudinal direction, so that it is difficult to stretch when it is pulled out from the rolled state, and the adhesive tape attached in the stretched state shrinks. It is possible to prevent the sticking position from shifting and the edge from rising due to peeling, and even when the tape is wound with tension to prevent the formation of cavities, it is unlikely to stretch. It is also possible to suitably prevent the deformation of the telescope shape (bamboo shoot shape) caused by the shrinkage of the adhesive tape 10 after being wound into a roll shape, thereby suppressing the occurrence of defective products and improving the yield. Was made.

Further, since the tensile strength of the adhesive tape 10 in the longitudinal direction could be improved, for example, when the adhesive tape 10 used as the masking tape is peeled off / removed from the adherend after the work such as painting is completed. In addition, the adhesive tape can be easily peeled off and removed without breaking.

In particular, the amount of the fiber piece 32 added is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, or the base material layer is the base material layer solid content with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive 31. It is a relatively small amount that only 0.2 to 10 parts by weight of the fiber piece needs to be contained with respect to 100 parts by weight, and the fiber piece 32 to be dispersed has a relatively small diameter of 0.05 to 100 denier. By using the adhesive tape 10, it was possible to suppress the elongation of the adhesive tape 10 and improve the tensile strength without sacrificing the hand-cutting property of the adhesive tape 10.

By using a relatively short fiber piece 32 to be added to the pressure-sensitive adhesive 31, which is 1 to 10 mm, preferably 1 to 7 mm, and more preferably 2 to 5 mm, the fiber piece 32 can be easily dispersed in the pressure-sensitive adhesive. On the other hand, even with the dispersion of fiber pieces of this length, it was possible to obtain the necessary suppression of elongation and improvement of tensile strength.

In the configuration in which a plurality of concave grooves (not shown) are formed on the uneven surface 22 of the base material layer 20 in a direction parallel to the longitudinal direction of the adhesive tape 10 at predetermined intervals, the hands in the width direction of the adhesive tape 10 are formed. Not only the cutability but also the hand cutability in the longitudinal direction could be imparted.

In the example in which the dispersion amount of the fiber pieces 32 in the pressure-sensitive adhesive layer 30 is reduced on the adhesive surface side with the adherend, or the structure does not include the fiber pieces 32, the fibers pieces 32 are also dispersed. It was possible to maintain good adhesiveness to the kimono.

Further, in the example in which the amount of the fiber pieces 32 dispersed in the pressure-sensitive adhesive layer 30 is also reduced on the adhesive surface side of the base material layer 20 with the uneven surface 22, or the fiber pieces 32 are not included, the base material layer is used. Strong adhesion between the uneven surface 22 of 20 and the pressure-sensitive adhesive layer 30 can be obtained, and when the pressure-sensitive adhesive tape 10 is peeled off from the adherend, delamination occurs and a part of the pressure-sensitive adhesive layer 30 is on the surface of the adherend. It was also possible to suitably prevent the occurrence of so-called "glue residue" that remains attached.

Furthermore, since there are many processes as a conventional base material layer, an adhesive tape that can replace the existing woven tape can be obtained without weaving expensive fibers vertically and horizontally (warp and weft), which brings about a high economic effect.

In the polypropylene and polyethylene mixed resin that has been tried in the past as a base material layer to solve the above problems, the deflection generated in the extruded film, the wrinkles in the winding, and the wrinkles in the line (Abara,) due to the difference in melting point. Although flare (also called flare) occurred frequently, the fiber pieces of the present application that replaced polypropylene were able to achieve the above effects and minimize the occurrence of such wrinkles.

In the schematic cross-sectional view of the adhesive tape of the present invention, FIG. 3A shows an embodiment in which the pressure-sensitive adhesive layer has fiber pieces, and FIG. 3B shows an embodiment in which the base material layer and the pressure-sensitive adhesive layer have fiber pieces. Shows the morphology. FIG. 6 is a schematic cross-sectional view of another adhesive tape of the present invention. FIG. 6 is a schematic cross-sectional view of still another adhesive tape of the present invention. The explanatory view of the manufacturing method of the polyolefin resin film which becomes a base material layer. A perspective view of the adhesive tape wound into a roll. Explanatory drawing of a conventional adhesive tape (corresponding to Patent Document 1). Explanatory drawing of a conventional adhesive tape (corresponding to Patent Document 2). Explanatory drawing of the conventional adhesive tape (corresponding to Patent Document 3). Explanatory drawing of the adhesive tape deformed into a telescope shape (bamboo shoot shape). Explanatory drawing of the conventional method of manufacturing an adhesive tape (corresponding to FIG. 3 of Patent Document 2).

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

[Overall structure]
As shown in FIGS. 1 to 3, the adhesive tape 10 of the present invention has a smooth surface 21 on one surface and a large number of concave grooves 23 formed on the other surface in a direction orthogonal to the longitudinal direction of the adhesive tape 10. The above-mentioned patent document is a self-cutting adhesive tape 10 in which a polyolefin resin film as a surface 22 is used as a base material layer 20 and an adhesive layer 30 is provided on the uneven surface 22 of the base material layer 20. It has the same configuration as the conventional adhesive tapes listed as 1 to 3.

In the adhesive tape 10 of the present invention, the fiber pieces 32 are dispersed in at least a part of the above-mentioned adhesive layer 30, so that the adhesive tape 10 can be stretched in the longitudinal direction while maintaining hand-cutting property, and the tensile strength can be suppressed. As an example, it is an adhesive tape having a total thickness of 120 to 300 μm.

[Base layer]
The film used as the base material layer 20 in the adhesive tape 10 of the present invention is an unstretched polyolefin resin film, which can be produced by using a known polyolefin resin.

Examples of such polyolefin resins include polyethylene resins, polypropylene resins, copolymer resins of ethylene and propylene, and copolymer resins of ethylene and / or propylene and one or more other α-olefins. It can be exemplified.

Examples of the α-olefin include butene-1, penten-1, hexene-1, heptene-1, octene-1, nonene-1, 4-methylpentene-1, and decene-1. ..

A polyethylene resin can be mentioned as an example of a preferable polyolefin resin.

The molecular weight of the polyolefin resin is not particularly limited as long as it can be molded into a film, but when expressed by the melt index, which is a measure of the flowability of the resin, it is generally in the range of 0.2 to 20 g / 10 minutes, preferably 1. The range is 10 g / 10 minutes (load 2.16 kg, temperature 190 ° C.).

The thickness of the above-mentioned polyolefin resin sheet serving as the base material layer 20 of the adhesive tape 10 of the present invention is, for example, in the range of 40 to 400 μm, but is not limited to this thickness, and is appropriately used depending on the application and the like. Can be set to thickness.

In this polyolefin resin sheet, one surface is a smooth surface 21 and the other surface is an uneven surface 22, and a large number of concave grooves 23 forming orthogonal to the longitudinal direction of the adhesive tape 10 are formed on the uneven surface 22. ing.

The concave groove 23 is a position where the base material layer 20 is broken when the adhesive tape 10 is cut by hand. If the groove 23 can be cut by hand, the cross-sectional shape thereof is In addition to the V-shape as shown in the figure, any shape such as a rectangular shape or a (semi-) circular shape may be used, and the depth thereof is not particularly limited, but the above-mentioned polyolefin having a sheet thickness of 40 to 400 μm. When the resin sheet is used as the base material layer 20, if the depth is less than 30 μm, the hand-cutting property is impaired. Therefore, a concave groove 23 of 30 to 300 μm, preferably 40 to 120 μm is formed, and the concave groove 23 is formed. The wall thickness at the formed portion is preferably 10 to 100 μm.

If the distance between the concave grooves 23 is less than 0.5 mm, the strength is insufficient in the longitudinal direction of the adhesive tape 10, and if it exceeds 5 mm, the original hand-cutting property may be insufficient. Therefore, as an example, 0. It can be set at intervals of 5 to 5 mm, preferably 0.6 to 1.4 mm. However, it may be formed wider or narrower than this.

FIG. 4 shows an example of a method for producing a polyolefin resin sheet using the above-mentioned polyolefin resin as a raw material, with one surface as a smooth surface 21 and the other surface as an uneven surface 22.

In the example shown in FIG. 4, after the molten polyolefin resin is extruded into a film from the extrusion die 51 of the extruder 50, the embossed roll 61 and the rubber roll 62 are in a state where the extruded film has not yet been completely cooled to room temperature. By passing through the space, a smooth surface 21 is formed on the contact side with the rubber roll 62, and a concave groove 23 having a shape corresponding to the ridge 61a provided on the surface of the emboss roll 61 is formed on the contact side with the emboss roll 61. ..

As shown in FIG. 4, the uneven surface 22 formed on the polyolefin resin film has a discharge electrode 64 and a smooth surface in order to improve the compatibility with the adhesive and prevent delamination from occurring. The corona discharge treatment may be performed when passing between the treatment rolls 65.

By performing the corona discharge treatment in this way, the affinity between the uneven surface 22 and the adhesive 31 described later (the anchoring property of the adhesive on the uneven surface and the wettability of the uneven surface) can be improved, and the adhesive tape 10 can be improved. It is possible to prevent the occurrence of so-called "glue residue" in which delamination occurs and the adhesive remains on the surface of the adherend when the adhesive is peeled off from the adherend.

As described above, the corona discharge treatment on the uneven surface 22 is preferable in order to improve the compatibility with the pressure-sensitive adhesive layer 30, but the corona discharge treatment is not essential for the adhesive tape 10 of the present invention, and if necessary. It suffices to process it.

The number of dyne (wetting index) of the base material layer 20 is preferably larger on the uneven surface 22 than on the smooth surface 21, and the preferable number of dyne (wetting index) is 30 Dyn / cm or less on the smooth surface 21 as an example. If the uneven surface 22 is 35 Dyn / cm or more and the wetting index of the smooth surface 21 is larger than 30 Dyn / cm, the smooth surface 21 and the adhesive layer 30 become more than necessary when the adhesive tape 10 is wound into a roll. The occurrence of the so-called "blocking phenomenon" in which the adhesive tape 10 is firmly adhered makes it difficult to deploy the adhesive tape 10.

On the other hand, if the wetting index of the uneven surface 22 is less than 35 Dyn / cm, the adhesive force of the adhesive 31 to the uneven surface 22 is insufficient, which causes the above-mentioned “glue residue” and the like.

In addition to the corona discharge treatment described above, there is also a method of applying a primer as a method for increasing the affinity of the pressure-sensitive adhesive layer 30 with respect to the uneven surface 22.

Improving the affinity by applying such a primer is also a well-known method, and it is possible to use various known primers such as rubber-based primers such as nitrile rubber and acrylic resin-based primers. it can.

As with the corona discharge treatment described above, the application of a primer is not essential in the present invention and can be appropriately performed as needed, and the primer can be used instead of the corona discharge treatment described above or in combination with the corona discharge treatment. You may apply it.

When fiber pieces are added to the substrate layer, the primary dispersion of the fiber pieces is kneaded with the polyolefin resin in a masterbatch and supplied to the extruder hopper. The fiber pieces used must exceed the thermal melting temperature of the polyolefin resin in the range of 200 ° C., and from these, polyester-based (Tg220 ° C.), nylon (Tg220 ° C.), and acrylic-based (thermosetting) are most preferable. Rayon, which is unrelated to thermosetting, is preferable, but polypropylene and polyester are preferable from the viewpoint of waterproofness.

The base material layer 20 in which the fiber pieces are dispersed is an unstretched polyolefin resin film, which can be produced by using a known polyolefin resin.

[Adhesive layer]
An adhesive layer 30 in which the fiber pieces 32 are dispersed is formed on the base material layer 20 made of the polyolefin resin film configured as described above and / or the uneven surface 22 of the base material layer 20.

Fiber pieces Examples of the above-mentioned fiber pieces 32 dispersed in the base material layer 20 or the pressure-sensitive adhesive layer 30 include acrylic, polyethylene, polypropylene, polyethylene terephthalate, 6-nylon, 6,6-nylon, polyparaphenylene terephthalamide, and poly. Fibers such as acrylic nitrile, vinylon, rayon, hemp, silk, and hair can be mentioned.

The fiber piece 32 may be a simple substance of short fibers such as cotton or hemp, wool, or a monofilament composed of fragments of these short fibers or long fibers such as silk or chemical fibers, or the monofilaments are twisted together. It may be a fragment of the obtained multifilament (thread).

Of these, the use of rayon, polyethylene, polypropylene, and polyethylene terephthalate is particularly preferable from the viewpoints of adhesiveness, heat resistance, solvent resistance, etc. to the polyolefin resin film used as the base material layer.

As the fiber piece 32 made of these raw materials, only the fiber piece 32 made of a single raw material may be used alone, but a plurality of types of fiber pieces 32 manufactured from different raw materials may be mixed and used. It may be a thing.

Further, as the fiber piece 32, a colored one can be used, or a fiber piece 32 manufactured by using a pre-colored raw material can be used.

The amount of the fiber piece 32 added is 0.5 with respect to 100 parts by weight of the adhesive solid content of the adhesive tape from the viewpoint of adhesive strength, toughness, hand cutting property, touch (softness), etc. of the obtained adhesive tape 10. The amount is preferably 10 parts by weight, more preferably 1 to 5 parts by weight.

The amount of the fiber pieces added to the base material layer is 0.2 to 10 parts by weight, here 0.5 to 3 parts by weight, with respect to 100 parts by weight of the solid content of the base material layer.

As the material used as the fiber piece 32 in the present invention, when an acrylic material described later is used as the adhesive, it is preferable to use an acrylic material, and the acrylic fiber piece is heat resistant. It is also preferable in terms of water resistance.

Further, polyester fiber is preferably used in terms of water resistance, and rayon fiber can also be preferably used in terms of heat resistance.

Adhesives As the adhesives constituting the adhesive layer 30, various known adhesives can be used, and examples thereof include acrylic adhesives, vinyl ether adhesives, silicone adhesives, and rubber adhesives. be able to.

The form of the pressure-sensitive adhesive to be used is not particularly limited, and any type of pressure-sensitive adhesive, emulsion-type pressure-sensitive adhesive, hot-melt-type pressure-sensitive adhesive, or the like may be used.

Method of Laminating the Adhesive Layer The above-mentioned adhesive layer 30 is formed by applying an adhesive in which fibers are dispersed in advance to the above-mentioned uneven surface 22 of the base material layer 20 or on process paper. After that, it is formed by transferring to the uneven surface 22 of the base material layer 20.

The pressure-sensitive adhesive layer 30 may be formed by, for example, a single-layer pressure-sensitive adhesive layer 30 formed by applying one layer of a pressure-sensitive adhesive in which fiber pieces 32 are dispersed, as shown in FIG. 1 (A). However, preferably, as shown in FIGS. 2 and 3, two or more layers of a plurality of types of pressure-sensitive adhesives (including a pressure-sensitive adhesive containing no fiber pieces) having different dispersion amounts of the fiber pieces 32 are applied to form a pressure-sensitive adhesive layer. The amount of dispersion of the fiber pieces 32 in the thickness direction of 30 may be provided with a gradient.

By dispersing the above-mentioned fiber piece 32 in the base material layer 20 and / or the pressure-sensitive adhesive layer 30, the base material layer 20 and / or the pressure-sensitive adhesive layer 30 is reinforced to reduce elongation and tensile strength. On the other hand, the pressure-sensitive adhesive layer 30 may cause the above-mentioned pseudo-crosslinking, which may cause a decrease in followability and adhesive strength to the surface of the adherend.

Therefore, as shown in FIG. 2, of the pressure-sensitive adhesive layer 30, the pressure-sensitive adhesive layer (shown) is formed by laminating a pressure-sensitive adhesive having a large content of relative fiber pieces 32 on the base material layer 20 side (upper side of the paper surface). In the example, the fiber piece-containing pressure-sensitive adhesive layer 301) is used, while the side that adheres to the adherend (lower side of the paper surface) is a pressure-sensitive adhesive with a small amount of the fiber piece 32 added, or a pressure-sensitive adhesive to which the fiber piece 32 is not added. A multi-layered pressure-sensitive adhesive layer may be formed as a pressure-sensitive adhesive layer (fiber piece-covered pressure-sensitive adhesive layer 302 in the illustrated example) formed by laminating.

Further, as shown in FIG. 3, in order to prevent delamination between the base material layer and the pressure-sensitive adhesive layer, a pressure-sensitive adhesive having a relatively large amount of dispersed fiber pieces 32 is laminated on the central portion of the pressure-sensitive adhesive layer 30 in the thickness direction. A pressure-sensitive adhesive layer (fiber piece-containing pressure-sensitive adhesive layer 301 in the illustrated example) is provided, while a pressure-sensitive adhesive having a small amount of fiber pieces dispersed or no fiber pieces dispersed around the adhesive layer is provided. A three-layered pressure-sensitive adhesive layer 30 on which a pressure-sensitive adhesive layer (first fiber piece-free pressure-sensitive adhesive layer 302a and second fiber-piece-free pressure-sensitive adhesive layer 302b in the illustrated example) formed by coating and laminating is formed. , Not only improving the adhesiveness with the adherend, but also improving the adhesiveness with the base material layer 20.

The adhesive tape 10 thus obtained is provided in the form of a roll formed by winding a predetermined length such as 25 m or 50 m as shown in FIG. 5, similarly to the known adhesive tape.

To improve the expandability of the adhesive tape 10 when the adhesive tape is provided in a rolled state, when a rubber-based adhesive is used as the adhesive, or when the amount of the adhesive applied is large. A known release agent may be applied to the smooth surface 21 of the base material layer 20.

The results of performance evaluation tests of the adhesive tape of the present invention (Examples 1 to 3) and the conventional adhesive tape (Comparative Example 1) are described below as examples, and the present invention is within the scope of these examples. Is not limited.

Test method An adhesive tape of the present invention (Examples 1 to 3) and a conventional adhesive tape (Comparative Example 1: corresponding to those described in Patent Document 1) are prepared, and the peeling adhesive strength (N /) of each adhesive tape is prepared. 25 mm), longitudinal tensile strength (N / 50 mm width), and elongation (%) were measured, and hand-cutting property was evaluated.

In the above test, the peeling adhesive strength (N / 25 mm), tensile strength (N / 50 mm width) and elongation (%) of the adhesive tape were measured based on JIS Z 0237-1991.

The peeling adhesive strength (N / 25 mm), tensile strength (N / 50 mm width) and elongation (%) are roughly as follows.

Peeling adhesive strength SUS304 steel sheet [surface finish BA (bright annealed finish / brightly heat-treated after cold rolling), surface roughness Ra50 ± 2.5 nm] adhesive tape (width 25 mm) attached to SUS304 steel sheet The average value of the force required when the length of 50 mm was peeled off at an angle of 180 ° was measured as the peeling adhesive force.

Tensile strength and elongation The chuck that grips the adhesive tape (width 50 mm) with an interval of 100 mm is separated at a speed of 5 ± 0.2 mm / s to pull the adhesive tape, and the load and elongation until the adhesive tape is cut are applied. The maximum load P (N) until cutting was taken as the tensile strength (N / 50 mm width).

In addition, the length of the adhesive tape used as the test piece, which is the length of the adhesive tape at the start of the test (the length at the time of cutting minus the length at the start of the test), is expressed as a percentage. did.

In addition, the evaluation of hand-cutting property is to evaluate the "straightness of the cutting point" and "easiness of cutting" when the adhesive tape is cut in the width direction only with the hand (fingertip), and it is easy to cut. In addition, those with straight cuts were evaluated as "○", and those with other cut points were evaluated as "×".

Example and Comparative Example [Example 1]
Base material layer As a polyolefin resin, 1 part by weight of polyethylene resin with a density of 0.96 g / cm ³ and a melt index of 7.0 g / 10 minutes (190 ° C, 2.16 kg / cm ² ) and a density of 0.92 g / cm ^3, a melt index was used a mixture of polyethylene resin 3 parts by weight of 4.0 g / 10 min ^{(190 ℃, 2.16kg / cm 2} ).

A molten sheet obtained by extruding the above resin at 160 to 190 ° C. is passed between a rubber roll having a smooth surface and an embossed roll, and one surface is a flat surface and the other surface is a recess of 0.08 mm in depth. A film having a thickness of 0.11 mm was obtained in which uneven surfaces having grooves formed at intervals of 1.2 mm were formed.

The uneven surface of the film was subjected to corona discharge treatment so that the wetting index was 45 Dyn to obtain a base film.

Adhesive layer The uneven surface 22 of the base material layer 20 is coated with an adhesive in which 1 part by weight of fiber pieces is dispersed with respect to 100 parts by weight of the adhesive solid content, and a drying furnace set at 80 to 120 ° C. is applied to 5 parts. After passing for a minute, as shown in FIG. 1 (A), the single-layer pressure-sensitive adhesive layer 30 was formed so that the finished thickness was 25 μm.

The pressure-sensitive adhesive used was an acrylic pressure-sensitive adhesive [“# AT-40D” manufactured by Saiden Chemical Co., Ltd. (a solution-type pressure-sensitive adhesive, and the solvent was a mixture of toluene and ethyl acetate in a weight ratio of 9: 1). Is a pressure-sensitive adhesive composed of 100 parts by weight [45% by weight] and 0.5 parts by weight of a polyisocyanate-based cross-linking agent [“Coronate L75” manufactured by Nippon Polyurethane Co., Ltd.].

A polyester fiber having a thickness of 1.2 denier and a length of 5 mm was dispersed as a fiber piece with respect to the above-mentioned pressure-sensitive adhesive solid content ratio of 100 parts by weight.

[Example 2]
Base material layer Same as in Example 1.
Adhesive layer A pressure-sensitive adhesive in which fiber pieces are dispersed is applied to the uneven surface 22 of the base material layer 20, and a pressure-sensitive adhesive containing no fiber pieces is further applied on the pressure-sensitive adhesive layer in which the fiber pieces are dispersed. , Dryed in the same manner as in Example 1, and as shown in FIG. 2, has a finished thickness (total thickness) of 25 μm having a two-layer structure of a fiber piece-containing adhesive layer 301 and a fiber piece-free adhesive layer 302. The pressure-sensitive adhesive layer 30 was formed.

The fiber piece-containing pressure-sensitive adhesive layer 301 is formed by applying the pressure-sensitive adhesive (dispersed fiber pieces) used in Example 1, and has a finished thickness of 15 μm.

The fiber piece-free pressure-sensitive adhesive layer 302 is formed by applying a pressure-sensitive adhesive having the same composition as the pressure-sensitive adhesive of Example 1 except that it does not contain fiber pieces, and has a finished thickness of 10 μm.

The fiber piece-containing pressure-sensitive adhesive layer 301 and the fiber piece-free pressure-sensitive adhesive layer 302 were formed on the uneven surface 22 of the base material layer 20 by coextrusion using a multilayer die (two layers).

[Example 3]
Base material layer Same as in Example 1.
Adhesive layer A pressure-sensitive adhesive containing no fiber pieces is applied to the uneven surface 22 of the base material layer 20, and a pressure-sensitive adhesive in which the fiber pieces 32 are dispersed is applied onto the pressure-sensitive adhesive containing no fiber pieces. A pressure-sensitive adhesive containing no fiber pieces is further applied onto the pressure-sensitive adhesive in which the fiber pieces 32 are dispersed, dried in the same manner as in Example 1, and applied to the uneven surface 22 of the base material layer 20 as shown in FIG. On the laminated first fiber piece-free pressure-sensitive adhesive layer 302a, the fiber piece-containing pressure-sensitive adhesive layer 301 laminated on the first fiber piece-free pressure-sensitive adhesive layer 302a, and the fiber-piece-containing pressure-sensitive adhesive layer 301. A pressure-sensitive adhesive layer 30 having a finished thickness (total thickness) of 30 μm having a three-layer structure of a second fiber piece-free pressure-sensitive adhesive layer 302b laminated on the surface was formed.

The first fiber piece-free pressure-sensitive adhesive layer 302a is formed by applying a pressure-sensitive adhesive having the same composition as the pressure-sensitive adhesive of Example 1 except that the fiber piece 32 is not contained, and has a finished thickness of 7 μm.

The fiber piece-containing pressure-sensitive adhesive layer 301 was formed by applying a pressure-sensitive adhesive in which 1.5 parts by weight of fiber pieces were dispersed to 100 parts by weight of the pressure-sensitive adhesive solid content to form a finished thickness of 15 μm. The pressure-sensitive adhesive used was , The same as that described in Example 1 except that the blending amount of the fiber pieces was increased by 0.5 parts by weight.

Further, the second fiber piece-free pressure-sensitive adhesive layer 302b is formed by applying a pressure-sensitive adhesive having the same composition as the pressure-sensitive adhesive of Example 1 except that the fiber piece 32 is not contained, and has a finished thickness of 8 μm. is there.

The first fiber piece-free pressure-sensitive adhesive layer 302a, the fiber piece-containing pressure-sensitive adhesive layer 301, and the second fiber-piece-free pressure-sensitive adhesive layer 302b are coextruded using a multilayer die (three layers) to form a base material layer. It was formed on the uneven surface 22 of 20.

[Comparative Example 1]
Base material layer Same as in Example 1.
Adhesive layer A pressure-sensitive adhesive containing no fiber fragments was applied to the uneven surface of the base material layer and dried in the same manner as described in Example 1 to form a pressure-sensitive adhesive layer having a finished thickness of 25 μm.

The pressure-sensitive adhesive used to form the pressure-sensitive adhesive layer is the same as the pressure-sensitive adhesive used in Example 1 except that it does not contain fiber fragments.

Test Results Using the adhesive tapes of Examples 1 to 3 and Comparative Example 1 described above, the peeling adhesive strength (N / 25 mm), tensile strength (N / 50 mm width) and elongation (%) were measured. The results of evaluating the hand-cutting property are shown in Table 1 below.

[Example 4]
Base material layer As shown in FIG. 1 (B), as a polyolefin resin, a polyethylene resin having a density of 0.96 g / cm ³ and a melt index of 7.0 g / 10 minutes (190 ° C., 2.16 kg / cm ² ) 1 For 3 parts by weight of polyethylene resin with a density of 0.92 g / cm ³ and a melt index of 4.0 g / 10 minutes (190 ° C, 2.16 kg / cm ² ) and 100 parts by weight of these polyolefin resins. One weight of a polyester fiber piece, a fiber thickness of 1.2 denier, and a length of 3 mm were kneaded.

A molten sheet obtained by extruding the above resin at 160 to 190 ° C. is passed between a rubber roll having a smooth surface and an embossed roll, and one surface is a flat surface and the other surface is 0.08 mm deep. A film having a thickness of 0.11 mm was obtained, in which uneven surfaces were formed in which the concave grooves were formed at intervals of 1.2 mm.

The uneven surface of the film was subjected to corona discharge treatment so that the wetting index was 45 Dyn to obtain a base film.

Adhesive layer Same as Example 1.

[Example 5] Example in which the pressure-sensitive adhesive layer does not contain fiber fragments Base material layer The same pressure-sensitive adhesive layer as in Example 4 The pressure-sensitive adhesive is applied to the uneven surface 22 of the base material layer 20 and set at 80 to 120 ° C. After passing through the drying oven for 5 minutes, a single-layer adhesive layer 30 was formed so as to have a finished thickness of 25 μm as shown in FIG.

The pressure-sensitive adhesive used was an acrylic pressure-sensitive adhesive [“# AT-40D” manufactured by Saiden Chemical Co., Ltd. (a solution-type pressure-sensitive adhesive, and the solvent was a mixture of toluene and ethyl acetate in a weight ratio of 9: 1). Is a pressure-sensitive adhesive composed of 100 parts by weight [45% by weight] and 0.5 parts by weight of a polyisocyanate-based cross-linking agent [“Coronate L75” manufactured by Nippon Polyurethane Co., Ltd.].

Consideration of Test Results From the above test results shown in Tables 1 and 2 above, the adhesive tape of the present invention has a tensile strength of 50 N as compared with the adhesive tape of Comparative Example 1 in both Examples 1 to 3. With the improvement (about 63%), the elongation decreased from 40% to 14 to 16% (decrease rate of about 60 to 65%), and in Examples 4 and 5, the tensile strength was 60 to 70 N (about 75). It was confirmed that the growth was improved from 40% to 11 to 12% or less (decrease rate of about 70 to 72.5%), and the growth was significantly reduced.

On the other hand, in spite of such an increase in tensile strength or a decrease in elongation, the adhesive tapes of Examples 1 to 5 all exhibit the same hand-cutting property as the adhesive tape of Comparative Example 1.

The adhesive tapes of Examples 1 to 3 have a peeling adhesive strength of 0.5 to 1 N lower than that of the adhesive tape of Comparative Example 1, but such a decrease in adhesive strength is practically possible. ， The decrease is not a problem.

From the above results, the structure in which the fiber pieces are dispersed in the adhesive layer adopted in the adhesive tape of the present invention is effective in increasing the tensile strength or reducing the elongation while maintaining the hand-cutting property of the adhesive tape. It was confirmed that.

As described above, as a result of the adhesive tape of the present invention being significantly reduced in elongation, it is difficult for elongation to occur when the adhesive tape is pulled out from the rolled state or when it is cut by hand, and as a result, it is attached to an adherend. It is considered that the attachment position does not shrink after being worn, and the attachment position can be prevented from shifting or peeling due to such shrinkage.

In addition, since the adhesive tape is unlikely to stretch even when it is wound in a roll shape by applying tension to prevent the formation of a cavity (cavity) due to the entrainment of air, the adhesive tape is wound in a roll shape. It is thought that the telescope-like (bamboo shoot-like) deformation caused by the adhesive tape shrinking in the longitudinal direction will be less likely to occur later, and the yield is expected to improve.

Further, since the tensile strength is increased, it is difficult to break or the like, so that the workability when peeling off the adhesive tape used for masking or the like from the adherend surface after the completion of the painting work is improved.

Moreover, since the tensile strength could be significantly improved to 130 (N / 50 mm width) by reinforcement with fiber pieces, the present invention weaves fibers with many steps and high cost in the vertical and horizontal directions (warp and weft). Adhesive tape that can be used as a substitute for the tape of the existing woven fabric base layer can be obtained without any problem, and it can be used not only as a masking tape or a curing tape used for painting, but also for bundling or packing materials, for example. It is sufficiently durable to be used as an adhesive tape used for such purposes.

10 Adhesive tape 20 Base material layer (polyolefin resin sheet)
21 Smooth surface 22 Concavo-convex surface 23 Concave groove 30 Adhesive layer 301 Fiber fragment-containing adhesive layer 302 Fiber fragment-free adhesive layer 302a First fiber fragment-free adhesive layer 302b Second fiber fragment-free adhesive layer 31 Adhesive 32 Fiber Piece 40 Winding Core 50 Extruder 51 Extruding Die 61 Embossing Roll 61a Convex 62 Rubber Roll 64 Discharge Electrode 65 Treatment Roll 100 Adhesive Tape 120 Base Material Layer 121 Smooth Surface 122 Concavo-convex Surface 123 Concave Groove 130 Adhesive Layer 131 Adhesive 135 Non-woven fabric or split cloth 136 Polyester resin 140 Roll core 150 Process paper

Claims (13)

A base material layer made of an unstretched polyolefin resin film having an uneven surface in which a plurality of concave grooves are formed at predetermined intervals on one side in a direction orthogonal to the longitudinal direction.
A pressure-sensitive adhesive layer formed on the uneven surface of the base material layer is provided.
An adhesive tape characterized in that fiber pieces are dispersed in the pressure-sensitive adhesive of the base material layer and / or the pressure-sensitive adhesive layer. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer contains 0.5 to 10 parts by weight of the fiber pieces with respect to 100 parts by weight of the solid content of the pressure-sensitive adhesive. The adhesive tape according to claim 1 or 2, wherein the fiber diameter of the fiber piece is 0.05 to 100 denier. The adhesive tape according to any one of claims 1 to 3, wherein the length of the fiber piece is 1 to 10 mm. The adhesive according to any one of claims 1, 3 or 4, wherein the base material layer contains 0.2 to 10 parts by weight of the fiber piece with respect to 100 parts by weight of the solid content of the base material layer. tape. The adhesive tape according to any one of claims 1 to 5, wherein the elongation in the longitudinal direction is 30% or less. The adhesive tape according to any one of claims 1 to 6, wherein the tensile strength in the longitudinal direction is 100 (N / 50 mm width) or more. Any of claims 1 to 4 or 6 to 7, wherein the pressure-sensitive adhesive layer has a structure in which the dispersion amount of the fiber pieces is reduced on the side to be attached to the adherend or does not contain the fiber pieces. The adhesive tape according to item 1. The adhesive tape according to claim 8, wherein the pressure-sensitive adhesive layer has a structure in which the dispersion amount of the fiber pieces is reduced on the side to be adhered to the base material layer or the pressure-sensitive adhesive layer does not contain the fiber pieces. The fiber piece is made of any material selected from the group of PET, olefin resin, rayon, vinylon, and nylon, and one type of the fiber piece or a mixture of two or more kinds is used as the pressure-sensitive adhesive layer. The adhesive tape according to any one of claims 1 to 9, wherein the adhesive tape is dispersed in. The adhesive is laminated on the uneven surface of the base material layer made of an unstretched polyolefin resin film having an uneven surface in which a plurality of concave grooves are formed at predetermined intervals in a direction orthogonal to the longitudinal direction of the adhesive tape on one side. When to form a pressure-sensitive adhesive layer together with the base layer and / or the pressure-sensitive adhesive layer, the production method of the adhesive tape, characterized in that to disperse the fiber pieces.
A plurality of types of adhesives having different dispersion amounts of the fiber pieces are laminated in multiple layers to reduce the dispersion amount of the fiber pieces on the adhesive surface side with the adherend, or the adhesive surface side with the adherend. The method for producing an adhesive tape according to claim 11, wherein the pressure-sensitive adhesive layer containing no fiber pieces is formed. A plurality of types of pressure-sensitive adhesives in which the dispersion amount of the fiber pieces is changed are laminated in multiple layers to reduce the dispersion amount of the fiber pieces on the adhesive surface side of the base material layer with the uneven surface, or the base material. The method for producing an adhesive tape according to claim 11 or 12, wherein the pressure-sensitive adhesive layer containing no fiber pieces is formed on the adhesive surface side of the layer with the uneven surface.

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