Adhesive tapes and adhesive products

Abstract

To provide an adhesive tape that has better followability to a curve or a curved surface shape than a conventional one, enhances adhesion working efficiency, reduces material waste loss, and enhances its appearance quality; and a bonded product.SOLUTION: The adhesive tape of the present invention includes at least an adhesion layer formed from a component A, and a release layer that is formed from a component B and covers one surface of the adhesion layer. A stress at the time when extensibility of the release layer is 50% is in a range of 1-25 MPa, a stress at the time when extensibility of the adhesion layer is 50% is in a range of 1-6 MPa, and a peel strength between the adhesion layer and the release layer is in a range of 0.05 N / cm to 0.5 N / cm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an adhesive tape that can conform to curves and curved surface shapes, improves the efficiency of bonding work, reduces material waste, and improves the appearance quality. [Background technology]

[0002] Conventionally, adhesive tapes disclosed include a tape having a hot-melt polyurethane adhesive layer on the surface of a polyurethane resin film (see, for example, Patent Document 1); a release film having shape-conforming properties obtained by laminating multiple thermoplastic resins with different softening points (see, for example, Patent Document 2); an adhesive sheet having a stretch-elastic and heat-resistant support sheet on at least one side of which a stretch-elastic hot-melt adhesive coating is provided (see, for example, Patent Document 3); an adhesive sheet containing cellulose fibers and an elastomer-based impregnating agent on the main surface of the support and having a breaking elongation of greater than 8% (see, for example, Patent Document 4); an adhesive tape using a foam substrate and a tackifying resin with a softening temperature lower than that of thermoplastic rubber (see, for example, Patent Document 5); and a laminated film using a layer containing polyarylene sulfide and a polyolefin-based resin layer (see, for example, Patent Document 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 11-172209 [Patent Document 2] Patent Publication No. 2005-205745 [Patent Document 3] Patent Publication No. 08-120231 [Patent Document 4] Special table flat 09-508933 [Patent Document 5] Patent Publication No. 2000-073025 [Patent Document 6] Patent Publication No. 2007-190689 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 has high peel strength and poor releasability due to the affinity between the urethane film and the urethane adhesive; the technology of Patent Document 2 uses multiple thermoplastic resins in the release film, which requires a lamination process and increases material costs; the technology of Patent Document 3 has high peel strength between components A and B and poor releasability; the technology of Patent Document 4 has poor conformability due to the suppression of elongation by the cellulosic fibers; the technology of Patent Document 5 makes it easy to bend and deform the adherend after adhesion, but the modulus of the tape itself is low, so the substrate tends to stretch more than necessary during adhesion, resulting in poor workability and releasability; and the technology of Patent Document 6 has poor heat resistance because it cannot withstand the ironing and pressing temperatures used in thermoplastic hot melt adhesion work due to its low glass transition temperature.

[0005] On the other hand, when adhesive tapes are applied to curved or curved surfaces, problems arise, such as wrinkles due to differences in inner and outer circumferences and time-consuming application procedures. To address these issues, many adhesive tapes have recently been developed, in which adhesive sheets are punched or mold-cut into the desired curved shape. However, adhesive tapes punched or mold-cut into the desired curved shape have waste because the portions other than the mold-cut or mold-cut portions are unnecessary, resulting in waste and environmental impact from plastic waste. In addition, mold-cutting or mold-cutting requires processing equipment and time, resulting in high production and material costs. Therefore, the object of the present invention is to provide an adhesive tape and adhesive-processed products that have heat resistance sufficient to withstand thermoplastic hot melt adhesive bonding, and that, despite being a linear tape, can conform to curved or curved shapes. This tape and adhesive-processed products can improve adhesion efficiency by eliminating the mold-cutting or mold-cutting process, reduce material waste, and improve appearance quality. [Means for solving the problem]

[0006] The adhesive tape and adhesive processed product of the present invention that can achieve the above object have the following configuration. (1) The adhesive tape of the present invention has at least an adhesive layer made of component A and a release layer made of component B covering one side of the adhesive layer, wherein the stress of the release layer at 50% elongation is in the range of 1 to 25 MPa or less, the stress of the adhesive layer at 50% elongation is in the range of 1 MPa to 6 MPa, and the peel strength between the adhesive layer and the release layer is in the range of 0.05 N / cm to 0.5 N / cm. (2) More preferably, component A is a thermoplastic hot melt. (3) More preferably, in the adhesive tape, the softening point T B1 is 100°C or higher, and the softening point T A1 is 100°C or less, and the softening point ratio (T B1 / T A1 ) is in the range of 2 to 5. (4) More preferably, in the adhesive tape, the melting point temperature T A2 The melting point temperature T of component B is B2 The melting point temperature ratio (T A2 / T B2 B) is in the range of 1.5 to 2.5. (5) More preferably, in the adhesive tape, the visible light transmittance VT of the component B B is 75% or less, and the visible light transmittance VT of the component A is A is 60% or more, and the visible light transmittance ratio (VT B / VT A ) is 80% or less.

[0007] (6) More preferably, in the adhesive tape, the breaking strength BS of the component B B is the breaking strength BS of component A A Higher, breaking strength ratio (BS B / BS A ) is 1 or greater. (7) More preferably, the adhesive tape has a yield point elongation of 25% to 27%, a yield point stress of 7 MPa to 16 MPa, and a lower yield point stress in the range of 7 MPa to 16 MPa. (8) Another preferred embodiment of the adhesive processed product of the present invention is an adhesive processed product using at least the adhesive tape, wherein the adhesive processed product has an adhesive part consisting of at least an adherend and an adhesive layer of the adhesive tape, the adhesive part at least partially having a curved shape with a radius of curvature in the range of 5 cm to 30 cm, the width of the adhesive tape is in the range of 5 mm to 30 mm, and the ratio of the maximum thickness to the minimum thickness (maximum thickness / minimum thickness) of the thickness at the outer edge and the thickness at the inner edge in the longitudinal direction of the curved shape of the adhesive part is in the range of 101 to 150%. [Effects of the Invention]

[0008] According to the present invention, an adhesive tape can be obtained which has the ability to conform to curves and curved surface shapes, improves the efficiency of the bonding work, reduces material waste, and improves the appearance quality. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of the adhesive tape of the present invention before single-sided bonding processing. [Figure 2] FIG. 2 is a cross-sectional view of the adhesive tape shown in FIG. 1 after one-sided bonding processing. [Figure 3] FIG. 3 is a cross-sectional view of the adhesive tape shown in FIG. 1 after double-sided adhesive processing. [Figure 4] FIG. 4 is an exploded perspective view of the adhesive tape of the present invention when used in a curved adhesive portion (before single-sided adhesive processing). [Figure 5] FIG. 5 is an exploded perspective view of the adhesive tape of the present invention when used in a curved adhesive portion (double-sided adhesive processing). [Figure 6] FIG. 6 is an enlarged cross-sectional view of a portion of the bonded product of FIG. [Figure 7] FIG. 7 is an image showing the distortion evaluation of the adhesive processed product of the present invention (after one-sided adhesive processing). [Figure 8] Figure 8 shows an image of a conventional adhesively processed product (after one-sided adhesive processing) for evaluating distortion. [Figure 9] FIG. 9 is a photograph showing the appearance of the adhesive processed product of the present invention shown in FIG. 7 (after one-sided adhesive processing). [Figure 10] FIG. 10 is a photograph of the appearance of the conventional adhesively processed product shown in FIG. 9 after one-sided adhesive processing. DETAILED DESCRIPTION OF THE INVENTION

[0010] The adhesive tape and adhesive processed product of the present invention will be described in detail below with reference to the drawings. (Configuration of the invention and explanation of drawings) Fig. 1 is a cross-sectional view of the adhesive tape of the present invention before one-sided adhesive processing. As shown in Fig. 1, the adhesive tape 1 of the present invention is composed of an adhesive layer 1a made of component A and a release layer 1b made of component B, and at least one surface of the adhesive layer 1a is covered with the release layer 1b. Component B functions as a release agent, and component A functions as an adhesive, fulfilling their respective roles in the adhesive tape. Before adhesive processing, the adhesive tape 1 has an adhesive layer 1a and a release layer 1b integrated together as shown in Figure 1. An adhesive processed product using the adhesive tape 1 of the present invention has an adhesive part consisting of the adhesive layer 1a and an adherend 2, and this adhesive part is formed by adhesive processing the adhesive tape 1 to the adherend 2.

[0011] Adhesion processing is mainly classified into single-sided adhesive processing and double-sided adhesive processing. Single-sided adhesive processing is a process in which one side of adhesive layer 1a of adhesive tape 1 is adhered to adherend 2 as shown in Figure 1, and then release layer 1b is removed to expose the other side of adhesive layer 1a as shown in Figure 2. The state of the adhesive part after the single-sided bonding process is such that one side of the adhesive layer 1a of the adhesive tape 1 is in contact with the adherend 2, the other side is exposed, and the release layer 1b has been removed. As shown in Figure 3, double-sided adhesive processing is a process in which the surface of adhesive layer 1a of adhesive tape 1 exposed in single-sided adhesive processing is adhered to another adherend 2', forming a state in which both surfaces of adhesive layer 1a are adhered to adherend 2 and adherend 2'. The state of the adhesive area after double-sided adhesive processing is such that both sides of adhesive layer 1a of adhesive tape 1 are in contact with adherend 2 and adherend 2', and release layer 1b has been removed. The adhesive area may be formed in any shape along the longitudinal direction of adhesive tape 1, such as a curved or arc-shaped, straight line, zigzag, or dotted line.

[0012] <Elongation stress> FIG. 4 is an exploded perspective view of the adhesive tape of the present invention when used in a curved adhesive joint (before single-sided bonding). When a linearly processed adhesive tape 1 of the present invention is applied to a curved or arcuate adhesive joint, a difference in arc length occurs between the outer edge 7 and the inner edge 6 of the adhesive tape 1. The adhesive tape 1 of the present invention has an appropriate stress for stretching when forming a curved or arcuate adhesive joint, thereby reducing wrinkles caused by distortion due to the difference in inner and outer circumference. By setting the stress at 50% elongation of component B constituting the release layer 1b to be 1 MPa or more and 25 MPa or less, the appearance quality of the adhesive processed product can be improved. The stress at 50% elongation represents the elongation stress under certain elongation conditions. If the stress at 50% elongation is less than 1 MPa, there is a problem of large deformation and poor shape stability, while if it is 25 MPa or more, there is poor conformability to curved or arcuate shapes. A more preferable range is 5 MPa or more and 20 MPa or less. By adjusting the stress at 50% elongation of component A constituting adhesive layer 1a to 0.5 MPa or more and 10 MPa or less, the appearance quality of the bonded product can be improved. If the stress at 50% elongation is less than 0.5 MPa, there is a problem of large deformation and poor shape stability, while if it is 10 MPa or more, it will be poor at following curves and arc shapes. A more preferable range is 1 MPa or more and 6 MPa. Note that the stress at 50% elongation is measured in accordance with JIS K 7127 at a tensile speed of 100 mm / min.

[0013] <Radius of curvature of adhesive joint> When forming the adhesive joint into a curved or arc-shaped shape, the difference in arc length between the outer edge 7 and inner edge 6 of the adhesive joint changes depending on the radius of curvature, and this difference in arc length also changes the distortion and wrinkles caused by the difference in inner and outer circumferences. Therefore, it is preferable that the radius of curvature of the adhesive joint be in a range that is less likely to cause such wrinkles. From the perspective of appearance quality, it is preferable that the radius of curvature of the adhesive joint of a bonded product be between 5 cm and 30 cm. This radius of curvature of the adhesive joint refers to the radius of curvature of the inner edge 6 of the adhesive layer 1a that forms the adhesive joint. If the radius of curvature of the adhesive joint is less than 5 cm, the difference in arc length between the outer edge and inner edge is large, which can lead to the problem of distortion and wrinkles caused by the difference in inner and outer circumferences. Conversely, if the radius of curvature is greater than 30 cm, the difference in appearance quality caused by the configuration of the tape body will be small.

[0014] <Adhesive tape width> When the adhesive layer 1a is formed into a curved or arc-shaped bond, wrinkles caused by the difference in arc length between the outer edge 7 and the inner edge 6 vary depending on the radius of curvature of the bonded portion as well as the width of the adhesive tape 1. The width of the adhesive tape 1 is preferably set within a range that makes wrinkles less likely to occur. From the perspective of appearance quality, the width of the adhesive tape 1 is preferably 5 mm or more and 50 mm or less. The width of the adhesive tape 1 refers to the length in the direction perpendicular to the longitudinal direction of the adhesive tape 1. If the width of the adhesive tape 1 is less than 5 mm, problems such as twisting and meandering due to its thinness are likely to occur. Conversely, if the width is 50 mm or more, bending when bonding into a curved or arc-shaped bond is difficult, and the difference in arc length between the outer and inner edges of the bonded portion becomes large, making it prone to wrinkles due to distortion caused by the difference in inner and outer circumferences. When the radius of curvature of the bonded portion of the bonded product is 5 cm or more and 30 cm or less, the width of the adhesive tape 1 is preferably 5 mm or more and 30 mm or less, more preferably 5 mm or more and 15 mm or less.

[0015] <Thickness ratio of inner and outer edges> In a bonded product 9 using the adhesive tape 1 of the present invention, when the adhesive portion is formed into a curved or arc-shaped adhesive layer 1a, the difference between the thickness at the longitudinal outer edge and the thickness at the inner edge is small, i.e., the ratio of the maximum thickness to the minimum thickness (maximum thickness / minimum thickness) between the two values ​​is small, which is preferable in terms of appearance quality because it makes unevenness, shadows, and wrinkles due to the thickness difference less visible. The ratio of the maximum thickness to the minimum thickness (maximum thickness / minimum thickness) between the thickness at the longitudinal outer edge and the thickness at the inner edge of the adhesive portion is preferably 101% or more and 150% or less. If the ratio of the maximum thickness to the minimum thickness (maximum thickness / minimum thickness) between the thickness at the longitudinal outer edge and the thickness at the inner edge of the curved or arc-shaped adhesive portion is less than 101% or more than 150%, unevenness, shadows, and wrinkles due to the thickness of the outer or inner edge are more easily visible. A range of 101% or more and 120% is more preferable. The thickness of the adhesive joint is measured based on JIS K 7130: 1999 Plastics - Films and Sheets - Thickness Measurement Method. The means for adjusting the thickness of the adhesive joint may vary depending on the production method, but may be any method, such as various molding methods such as T-die, injection, and inflation, or coating methods such as knife overcoating and gravure, although T-die molding is preferred in terms of applicable thickness, shape, etc.

[0016] <Ratio of inner and outer edge lengths> In an adhesive processed product 9 using the adhesive tape 1 of the present invention, when the adhesive portion is formed into a curved or arc-shaped shape, a small difference between the length of the longitudinal outer edge of the adhesive layer 1a and the length of the inner edge, i.e., a small ratio between the two (outer edge length / inner edge length), is preferable in terms of ease of bonding and appearance quality, as distortion and wrinkles due to the difference between the inner and outer circumferences are less visible. From the viewpoints of ease of bonding and appearance quality, it is preferable that the ratio of the longitudinal outer edge length of the adhesive portion to the length of the inner edge (outer edge length / inner edge length) is less than 140%. If the ratio of the longitudinal outer edge length of the adhesive portion to the length of the inner edge (outer edge length / inner edge length) is 140% or more, wrinkles and shadows due to distortion due to the difference between the inner and outer circumferences are easily visible, and adhesive processing is difficult. A more preferable range is 100% or more and 130% or less. The ratio of the length of the inner edge of the adhesive joint to the length of the outer edge is calculated by taking the center point of the arc with the largest radius of curvature among the arc-shaped portions of the adhesive joint, drawing two radius lines from this center point to the outer edge of the adhesive joint, measuring the arc length of the inner edge and the arc length of the outer edge between the two radius lines, and then calculating the ratio of the two, i.e., dividing the arc length of the outer edge by the arc length of the inner edge, using the following formula (arc length of the outer edge ÷ arc length of the inner edge).

[0017] <Peel strength> As shown in FIG. 2 , the adhesive tape 1 of the present invention includes the step of removing the release layer 1b after adhering one side of the adhesive layer 1a of the adhesive tape 1 to the adherend 2, i.e., peeling the adhesive layer 1a from the release layer 1b. In this peeling step, it is preferable to impart a suitable peel strength between the adhesive layer 1a and the release layer 1b so that the adhesive layer 1a and the release layer 1b can be easily peeled from each other and will not naturally peel apart outside of this step. From the viewpoint of ease of peeling when removing the release layer 1b after adhering one side of the adhesive layer 1a to the adherend 2 in the single-sided adhesive process described above, it is preferable that the peel strength between the adhesive layer 1a and the release layer 1b be 0.05 N / cm or more and 0.5 N / cm or less. If the peel strength between the adhesive layer 1a and the release layer 1b is less than 0.05 N / cm, there is a problem in that the adhesive layer 1a and the release layer 1b tend to peel spontaneously apart outside of the bonding process. Conversely, if the peel strength is 0.5 N / cm or more, the adhesive layer 1a and the release layer 1b are less likely to peel apart after the single-sided bonding process. A more preferable range is 0.05 to 0.2 N / cm. The peel strength between the adhesive layer 1a and the release layer 1b was measured according to JIS L 1093 (2011) 7.1.1A-1 method at a tensile speed of 300 mm / min. The means for adjusting the peel strength of the adhesive layer 1a and the release layer 1b may vary depending on the manufacturing method, but may include applying the adhesive layer 1a onto the release layer 1b using the T-die method or various coating methods, or conversely, applying the adhesive layer 1a onto the release layer 1b using various coating methods similar to those described above, or manufacturing the adhesive layer 1a and the release layer 1b separately and then laminating them by applying heat or the like.However, from the standpoint of cost and ease of production, a method of continuous processing, such as applying the adhesive layer 1a onto the release layer 1b or applying the release layer 1b onto the adhesive layer 1a, is preferred, and the T-die method is preferred as this method.

[0018] <Adhesive layer> The type of component A that constitutes the adhesive layer 1a is mainly an organic adhesive, and the types of organic adhesives are broadly classified into natural resin-based adhesives such as natural rubber casein, semi-synthetic adhesives such as cellulose acetate, and synthetic resin-based adhesives using polyurethane, acrylic, etc., but synthetic resin-based adhesives are preferred in terms of processability and cost. Synthetic resin types are subdivided into resin systems using polyurethane, polyester, PVA, PVC, acrylic resin, polyethylene, ethylene-vinyl acetate polymer, polyamide systems, etc., elastomer systems using silicone rubber, nitrile rubber, etc., and composite systems using nylon-epoxy, vinyl-phenolic, etc., but thermoplastic systems are more preferred as they have flexibility while providing excellent strength for Component A itself. Synthetic resin types include dry-solidifying types such as water-soluble, latex, and dispersion types; chemical reaction types that harden when a crosslinking reaction occurs by mixing the base resin with a curing agent; hot-melt types that are solid at room temperature but melt when heated and harden when cooled; and pressure-sensitive types that apply pressure to a highly viscous, fluid liquid to create an adhesive bond. Hot-melt types (thermoplastic hot melts) are more preferred as they have excellent adhesive strength at the interface between the adherend and component B. Suitable resin components for hot melt adhesives (thermoplastic hot melts) include ethylene-vinyl acetate polymers, polyamides, polyesters, polyurethanes, and polyolefins, with polyurethanes being more preferred as they are highly processable and undergo crosslinking reactions with moisture (humidity) in the air, resulting in excellent heat resistance, adhesive strength, and durability.

[0019] <Release layer> The type of component B constituting the release layer is not particularly limited as long as it is a resin having a stress of 1 to 6 MPa at 50% elongation. Examples include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polylactic acid, polycarbonate, polystyrene, polyphenylene sulfite, fluorine-based resins, and mixtures thereof. Among these, polyolefin-based resins are preferred from the viewpoint of excellent productivity, elongation, and flexibility. Furthermore, a mixture of polyolefin-based resins with up to about 40% by mass of synthetic rubber is also preferred as component B.

[0020] <Adhesion processing method> The adhesive processing method for bonding the adhesive tape 1 to the adherends 2, 2' is preferably mainly a heat press method, a high frequency heating method, or an ultrasonic processing method, but any of these may be used, and the heat press method is more preferred as it is superior in terms of cost and productivity.

[0021] <Softening> As described above, the adhesive tape 1 of the present invention is subjected to adhesive processing by heating, and therefore, it is preferable from the viewpoint of adhesion to the adherend and adhesive processing stability that the component A constituting the adhesive layer 1a is easily softened and the component B constituting the release layer 1b is not easily softened under the heat processing temperature conditions. B1 The softening point T of component B is preferably 100°C or higher from the viewpoints of adhesion to the adherend and stability in adhesive processing. B1 If the softening point T of component A is less than 100°C, the shape retention as a release agent will be poor. A more preferable softening point T is in the range of 130°C or more and 240°C or less. A1 The softening point T of component A is preferably 40°C or higher and 130°C or lower from the viewpoints of adhesion to the adherend and stability in adhesive processing. A1 If the temperature is less than 40°C, the adhesive resin will be close to room temperature and will not be able to maintain its shape, whereas if the temperature is 130°C or higher, the adhesive resin will be poor in processability and moldability. A more preferred range is 50°C or higher and 110°C or lower. In the present invention, component B plays the role of a release agent, so the softening point of component B is higher than that of component A, which plays the role of an adhesive. B1 is 100°C or higher, and the softening point T A1 It is preferable that the ratio of the two (T B1 / T A1 ) is in the range of 2 to 5. The softening point was measured using a TA Instruments DMAQ800 in temperature rise / control force mode at a temperature rise rate of 10°C / min, and was determined as the temperature at the first change point in the load value.

[0022] <Melting property> In a more preferred embodiment, under the heat processing temperature conditions, component A constituting the adhesive layer 1a is easily melted, and component B constituting the release layer 1b is hardly melted, which is preferable in terms of excellent adhesion to the adherend and adhesive processing stability. B2 is the melting point temperature T of component A A2 A higher melting point T of component A is preferable from the viewpoint of shape stability during adhesive processing. A2 is the melting point temperature T of component B B2 If the melting point T of component B is less than 100°C, the component B, which is the release agent, will melt before the component A, which is the adhesive resin, melts during the bonding process, which can cause problems during the bonding process. B2 and the melting point temperature T of component A A2 Ratio to (T B2 / T A2 ) is in the range of 1.5 to 2.5. The melting point temperature was measured using a TA Instruments DMAQ800 in a temperature rise / control force mode at a temperature rise rate of 10°C / min, and the point at which the strain displacement amount changes significantly was taken as the melting point.

[0023] <Breaking strength> In the adhesive tape of the present invention, it is necessary that the release layer 1b does not break during adhesive processing, and it is preferable from the viewpoint of workability that the component B constituting the release layer 1b has a predetermined breaking strength. Breaking strength BS of component B B is the breaking strength BS of component A A A higher breaking strength BS of component B is preferable from the viewpoint of shape retention. B is the breaking strength BS of component A A If the thickness is less than 1 / 2 mm, there is a problem that component B constituting release layer 1b cannot maintain the shape of component A during one-sided bonding processing. The breaking strength is measured in accordance with JIS K 7127 at a tensile speed of 100 mm / min.

[0024] <Visibility> From the viewpoint of workability, it is preferable that the adhesive tape 1 of the present invention suppresses visible light transmission, i.e., makes it difficult to see through, so that the position and outline of the adhesive tape 1 can be easily recognized during the adhesive processing. B From the viewpoint of visibility of the adhesive tape during adhesive processing, it is preferable that the visible light transmittance VT of the component A constituting the adhesive layer 1a is 0.75 or less. A It is preferable that the visible light transmittance VT of component A is 0.6 or more from the viewpoint of the appearance quality of the adhesive processed product 9. A If the visible light transmittance VT of the component B is less than 0.6, the component A causes a difference in the density of the adhesive portion of the adhesive processed product 9 after double-sided adhesive processing, resulting in a deterioration in the appearance quality. B If the ratio of the visible light transmittance of component B to that of component A is more preferably 0.75, component B is difficult to see during one-sided adhesive processing, resulting in poor workability. B / VT A ) is in the range of 80% or less. The visible light transmittance is measured in accordance with JIS A5759. The visible light transmittance can be adjusted by any method, such as mixing a pigment or dye with component A and component B, or by various printing methods such as gravure printing, inkjet printing, and screen printing, or vapor deposition. However, from the viewpoints of cost, simplicity, and coloring stability, the method of mixing an appropriate amount of pigment is preferred.

[0025] <Yield point elongation stress> In order to provide the adhesive tape 1 of the present invention with the ability to follow curves and other bent shapes during single-sided bonding processing, it is preferable from the standpoints of workability and appearance quality that it is easily plastically deformed in response to the elongation or load applied during processing. A preferred form of adhesive tape 1 that is susceptible to plastic deformation during single-sided adhesive processing is one in which the elongation and load at which adhesive tape 1 undergoes plastic deformation, i.e., yield point elongation, yield point stress, and lower yield point stress, are equivalent to the respective ranges of values ​​applied during processing. From the viewpoint of conformability to curves and other bending shapes during single-sided adhesive processing, it is preferable for the yield point elongation of adhesive tape 1 to be between 25% and 27%. The yield point elongation of such an adhesive tape represents the magnitude of elongation at which, when tension is applied to adhesive tape 1, the adhesive tape 1's deformation rapidly increases beyond its elastic limit and no longer returns to its original shape. If the yield point elongation of adhesive tape 1 is less than 25%, it will be difficult to plastically deform in response to the elongation or load applied during processing, resulting in problems with workability and poor appearance. Conversely, if it is greater than 27%, the adhesive tape will deform more than necessary, resulting in poor shape retention. More preferably, the yield point elongation of component B is in the range of 6% or more and 18% or less, and the yield point elongation of component A is in the range of 15% or more and 45% or less. The yield point elongation of such an adhesive tape is measured in accordance with JIS K 7127. Any method may be used to adjust the yield point elongation of the adhesive tape, such as increasing or decreasing the thickness of the adhesive layer 1a and / or the release layer 1b, stretching, or selecting the components A and B. However, from the viewpoint of the ability to follow a curve or other bending shape during single-sided bonding processing, adjustment by the stretching conditions of the adhesive layer 1a and / or the release layer 1b is preferred.

[0026] The yield stress and lower yield stress of the adhesive tape 1 of the present invention are preferably 7 MPa or more and 16 MPa or less, from the viewpoint of conformability to curves and other bending shapes during single-sided adhesive processing. The yield stress and lower yield stress of the adhesive tape 1 represent the magnitude of stress at which, when a load is applied to the adhesive tape 1, the adhesive tape's deformation increases rapidly beyond its elastic limit and no longer returns to its original shape. Of these, the lower yield stress represents the lowest stress when the tape is yielding. If the yield stress and lower yield stress of the adhesive tape 1 are less than 7 MPa, the adhesive tape 1 will undergo excessive elastic deformation, resulting in poor shape retention. Conversely, if the stress is 16 MPa or more, the adhesive tape 1 will be less susceptible to plastic deformation in response to the elongation or load applied during processing, resulting in poor workability and poor appearance. More preferably, the yield stress of component B is in the range of 17 MPa to 53 MPa and the yield stress of component A is in the range of 1 MPa to 5 MPa, and the lower yield stress of component B is in the range of 12 MPa to 39 MPa and the yield stress of component A is in the range of 1 to 5 MPa. The yield stress and lower yield stress of the adhesive tape 1 were measured in accordance with JIS K 7127, and the measured values ​​of the yield point and lower yield point were obtained from an elongation-stress curve. Any method may be used to adjust the yield stress and lower yield stress of the adhesive tape 1, such as increasing or decreasing the thickness of the adhesive layer 1a and / or the release layer 1b, stretching, or selecting the components A and B. However, adjustment by the stretching conditions of the adhesive layer 1a and / or the release layer 1b is preferred in terms of the ability to follow curves and other bending shapes during single-sided bonding processing.

[0027] <Adherend> The material for the adherends 2, 2' is mainly a woven or knitted fiber fabric or a nonwoven fabric. Woven or knitted fabrics are more preferable because they have excellent strength. When using woven fabrics, generally, plain weave, twill weave, satin weave, and their variations and multiaxial weaves are preferably used. When using knitted fabrics, plain knit, rib knit, purl knit, tricot, raschel, Milanese, etc. are preferably used. When using nonwoven fabrics, papermaking methods, chemical bonding methods, heat fusion methods, water jet punching methods, melt-blowing methods, flash spinning methods, etc. are preferably used.

[0028] <Application> The adhesive processed product 9 using the adhesive tape 1 of the present invention may be used for any of the following purposes: clothing, hats, gloves, futons, sheets, curtains, tents, sleeping bags, umbrellas, bags, etc. Furthermore, the adhesive processed product 9 of the present invention may be constructed by combining an adhesive section using the adhesive tape 1 of the present invention with a sewn section using a sewing machine. The sewn section can also be replaced with an adhesive section. In other words, the adhesive section can be used as a seam to join at least the adherends together. [Example]

[0029] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. The adhesive tapes and adhesive processed products used in the examples and comparative examples were evaluated by the following methods.

[0030] (Measurement items) [Disposal loss rate (%)] The waste loss rate (%) in the cutting process or molding process of the adhesive tape etc. of the present invention was calculated by measuring the cut area of ​​the tape and the area other than the adhesive portion that was generated, i.e., the waste area, and then calculating the ratio of the waste area to the cut area of ​​the tape, i.e., the waste area divided by the cut area of ​​the tape, using the following formula (waste area ÷ cut area of ​​tape).

[0031] [Ratio of inner edge length to outer edge length of adhesive joint (%)] An adhesive processed product having an arc-shaped joint was produced using the adhesive tape or the like of the present invention, and the ratio of the inner edge length to the outer edge length of this adhesive joint was determined by taking the center point of the arc with the largest radius of curvature among the arc-shaped parts of the adhesive joint, drawing two radius lines from this center point to the outer edge of the adhesive joint, measuring the arc length of the inner edge and the arc length of the outer edge between the two radius lines, and then dividing the ratio of the two, i.e., the arc length of the outer edge by the arc length of the inner edge, using the following formula (arc length of the outer edge ÷ arc length of the inner edge).

[0032] [Thickness ratio (%)] An adhesive processed product having an arc-shaped joint was produced using the adhesive tape or the like of the present invention, and the ratio of the thickness at the outer edge of this adhesive joint in the longitudinal direction to the thickness at the inner edge was measured in accordance with JIS K 7130:1999 Plastics - Film and Sheet Thickness Measurement Method, and the ratio was calculated by dividing the thickness at the maximum part by the thickness at the minimum part, that is, using the following formula (thickness at maximum part ÷ thickness at minimum part).

[0033] [Processing speed (cm / min)] The processing speed of adhesively processed products using the adhesive tape of the present invention was calculated by dividing the processing time required for one-sided adhesive processing of the adhesive part by the length of the adhesive tape in the longitudinal direction, that is, by the following formula (processing time required for one-sided adhesive processing ÷ length of adhesive tape in the longitudinal direction).

[0034] (evaluation) [Appearance quality] The appearance quality of adhesive processed products, which were adhesively processed using the adhesive tape of the present invention, i.e., the degree of wrinkles and distortion, was evaluated on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the better the appearance quality. The average of the evaluation scores from the five evaluators was used as the evaluation result, and an evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0035] [Adhesive workability] Five workers evaluated the ease of adhesive processing when using the adhesive tape of the present invention, i.e., the degree to which the adhesive portion conforms to curved shapes such as curves during single-sided adhesive processing, on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the better the adhesive workability. The average of the evaluation scores of the five workers was used as the evaluation result, and an evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0036] [Environmental friendliness] When adhesive processing was performed using the adhesive tape of the present invention, the ratio of the waste area to the cut area of ​​the tape was measured and evaluated using the evaluation criteria in Table 1 on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the better the environmental friendliness and reduction of material waste loss. An evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0037] [Visibility] Five workers evaluated the ease of visibility of the adhesive tape when adhesive processing was performed using the adhesive tape of the present invention, i.e., the degree of visibility of the position and outline of the adhesive tape body during single-sided adhesive processing, on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the better the visibility. The average of the evaluation scores of the five workers was used as the evaluation result, and an evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0038] [Color uniformity inside and outside the adhesive joint] Five workers evaluated the color uniformity inside and outside the bonded area when adhesive processing was performed using the adhesive tape of the present invention, i.e., the degree of shading visible between the bonded area and the area adjacent to the bonded area after double-sided adhesive processing, on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the less noticeable the shading in the bonded area, i.e., the better the color uniformity inside and outside the bonded area. The average evaluation score of the five workers was used as the evaluation result, and an evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0039] [Mold releasability] Five workers evaluated the releasability of the release layer when adhesive processing was performed using the adhesive tape of the present invention, i.e., the ease of peeling when peeling and removing the release layer from the adhesive layer after adhering one side of the adhesive layer of the adhesive tape to an adherend in single-sided adhesive processing, on a 7-point scale (-3 to 3, in 1-point increments). The higher the evaluation score, the better the release properties. The average of the evaluation scores of the five workers was used as the evaluation result, and an evaluation result of 1 point or more was considered good. The evaluation criteria are shown in Table 1.

[0040] [comprehensive evaluation] The total scores for the evaluation items of appearance quality, adhesive workability, environmental friendliness, visibility, color uniformity inside and outside the adhesive area, and releasability were calculated and used as the overall evaluation. The higher the evaluation score, the better the overall evaluation, and an evaluation result of 9 points or more was considered to be a good adhesive tape or adhesive processed product. The evaluation criteria are shown in Table 2.

[0041] [Table 1]

[0042] [Table 2]

[0043] Example 1 An adhesive processed product with the shape shown in Figure 5 was produced. A resin consisting of a mixture of 70% by mass of polypropylene and 30% by mass of synthetic rubber with a softening point of 150°C and a melting point of 199°C was used as component B. This resin was extruded and stretched into a sheet using an extrusion method to a thickness of 50 μm, a stress of 8.2 MPa at 50% elongation, and a breaking strength of 30.5 MPa, to obtain release layer 1b. The amount of pigment blended was adjusted so that the visible light transmittance of release layer 1b was 45%. Next, a resin mainly composed of a polyester-based polyurethane resin with hot-melt adhesive properties, a softening point of 60°C, and a melting point of 115°C, was used as Component A. This was extruded and stretched into a sheet with a thickness of 100 μm, a stress of 3.4 MPa at 50% elongation, and a breaking strength of 26.7 MPa, to obtain adhesive layer 1a. The amount of pigment added was adjusted so that the visible light transmittance was 89%. The obtained adhesive layer 1a was applied in sheet form onto the release layer 1b and laminated to form an adhesive sheet consisting of the adhesive layer 1a and the release layer 1b.The adhesive sheet was then slit to obtain an adhesive tape with a width of 10 cm and a peel strength of 0.18 N / cm.

[0044] Next, a taffeta fabric with a warp density of 250 threads / inch and a weft density of 164 threads / inch, consisting of a 17 dtex-7f nylon filament false twisted yarn for the warp and a 26 dtex-20f nylon filament false twisted yarn for the weft, was used as the adherend, and the exposed surface of adhesive layer 1a of the adhesive tape was placed against the adherend, heated to 100°C with an iron, and one-sided adhesive processing was performed to draw a curve with a radius of curvature of 30 cm. Next, the release layer 1b is peeled off and removed, and the adhesive layer 1a is sandwiched between two adherends as shown in FIG. 5, and the adhesive layer 1a is pressed at a temperature of 150°C and a pressure of 200 g / cm using a flat plate heat press. 2 The double-sided adhesive processing was carried out under the conditions of 10 seconds and 10 seconds, and an adhesive processed product was obtained. The resulting adhesive tape was measured for waste loss rate, ratio of inner edge length to outer edge length of the adhesive part, thickness ratio, and processing speed. Next, appearance quality, adhesive workability, environmental friendliness, visibility, color uniformity inside and outside the adhesive joint, and releasability were evaluated according to the criteria shown in Table 1, and an overall evaluation was made according to the criteria shown in Table 2. Table 3 shows the numerical values ​​and evaluation results. The adhesive sheet obtained in Example 1 was slit into adhesive tapes with widths of 10 mm, 30 mm, and 50 mm, and adherends with radii of curvature of 10 cm, 30 cm, and 40 cm were bonded to one side of the tape with the different widths, and distortion was evaluated. Figure 7 shows an image of the distortion evaluation, and Figure 9 shows a photograph of the appearance.

[0045] Example 2 In the adhesive tape of Example 1, a resin having a softening point of 151°C and a melting point of 206°C, consisting of a mixture of 90% by mass of polypropylene and 10% by mass of synthetic rubber, was used as component B, and the resin was extruded and stretched to a stress of 14.5 MPa at 50% elongation and a breaking strength of 56.3 MPa to obtain a release layer. A sheet-shaped adhesive tape was produced in the same manner as in Example 1, and slit to obtain an adhesive tape with a width of 30 mm and a peel strength of 0.12 N / cm. An adhesive processed product was produced under the same conditions as in Example 1, except that the radius of curvature of the adhesive joint was 10 cm. Table 3 shows the various values ​​and evaluation results.

[0046] Example 3 A sheet-shaped adhesive tape was prepared in the same manner as in Example 1, except that a resin consisting of a mixture of 80% by mass of polypropylene and 20% by mass of synthetic rubber with a softening point of 155°C and a melting point of 197°C was used as component B, and a release layer with a stress of 11.4 MPa at 50% elongation, a breaking strength of 51 MPa, and a visible light transmittance of 65% was obtained. The adhesive tape was then slit to obtain an adhesive tape with a width of 5 mm and a peel strength of 0.16 N / cm. An adhesive processed product was prepared under the same conditions as in Example 1, except that the radius of curvature of the adhesive joint was 5 cm. Table 3 shows the numerical values ​​and evaluation results.

[0047] Example 4 A sheet-shaped adhesive tape was produced in the same manner as in Example 1, except that a polyethylene-based resin with a softening point of 80°C and a melting point of 150°C was used as component B, and a release layer with a stress of 12.7 MPa at 50% elongation, a breaking strength of 22.1 MPa, and a visible light transmittance of 97% was obtained. The tape was then slit to obtain an adhesive tape with a width of 30 mm and a peel strength of 0.09 N / cm. An adhesive processed product was produced under the same conditions as in Example 1, except that the radius of curvature of the adhesive joint was 30 cm. Table 3 shows the numerical values ​​and evaluation results.

[0048] (Comparative Example 1) In the adhesive tape of Example 1, a polypropylene-based resin with a softening point of 142°C and a melting point of 202°C was used as component B to form a release layer with a film thickness of 400 μm, a stress of 27 MPa at 50% elongation, a breaking strength of 72 MPa, and a visible light transmittance of 65%. The polyester-based polyurethane resin-based resin used in Example 1 was used as component A to form an adhesive layer with a film thickness of 30 μm and a stress of 0.5 MPa at 50% elongation, resulting in an adhesive tape with a width of 50 mm and a peel strength of 1 N / cm. The radius of curvature of the adhesive joint was 40 cm, and the adhesive processed product was otherwise identical to Example 1. Table 3 shows the numerical values ​​and evaluation results.

[0049] (Comparative Example 2) In the adhesive tape of Example 1, a resin primarily composed of a polyester-based polyurethane resin with a softening point of 60°C and a melting point of 115°C was used as Component B to form a release layer with a film thickness of 50 μm, a stress of 0.5 MPa at 50% elongation, a breaking strength of 26 MPa, and a visible light transmittance of 89%. The resin primarily composed of the polyester-based polyurethane resin used in Example 1 was used as Component A to form an adhesive layer with a film thickness of 30 μm, a stress of 0.5 MPa at 50% elongation, and a breaking strength of 27 MPa, resulting in a 30 mm wide adhesive tape. The radius of curvature of the adhesive joint was 4 cm, and the adhesive processed product was otherwise identical to Example 1. Peel strength could not be measured because breakage occurred before the separation of Components A and B. Table 3 shows the numerical values ​​and evaluation results.

[0050] (Comparative Example 3) In the adhesive tape of Example 1, component B constituting the release layer was a release paper laminated on both sides of a cellulose paper fiber, with a polypropylene coating. A release layer with a film thickness of 300 μm and a stress-to-break MPa at 50% elongation, a breaking strength of 45.9 MPa, and a visible light transmittance of 19% was formed. Component A constituting the adhesive layer was a resin mainly composed of nylon resin with a softening point of 67 ° C and a melting point temperature of 136 ° C. A film thickness of 100 μm and a stress-to-break MPa at 50% elongation, a breaking strength of 47.5 MPa, and a visible light transmittance of 18% was formed. This resulted in an adhesive tape with a width of 50 mm and a peel strength of 0.01 N / cm. The radius of curvature of the adhesive joint was 10 cm, and the adhesive processed product was otherwise identical to Example 1. The softening point and melting point of component B that constitutes the release layer could not be measured because no softening point was observed and decomposition occurred before melting. Table 3 shows the respective values ​​and evaluation results. The adhesive sheet obtained in Comparative Example 3 was slit into adhesive tapes with widths of 10 mm, 30 mm, and 50 mm, and adherends with radii of curvature of 10 cm, 30 cm, and 40 cm were bonded to one side of the tape with the different widths, and distortion was evaluated. Figure 8 shows an image of the distortion evaluation, and Figure 10 shows a photograph of the appearance.

[0051] Comparative Example 4 For the adhesive tape and adhesive processed product of Comparative Example 3, an adhesive sheet consisting of an adhesive layer and a release layer was formed, and then the adhesive sheet was cut using a laser cutter to follow the curved shape of the adhesive portion, yielding an adhesive tape with a 4 cm radius of curvature, a 4 mm tape width, and a peel strength of 0.01 N / cm. The radius of curvature of the adhesive portion was set to 4 cm, and an adhesive processed product was produced that was otherwise identical to Comparative Example 3. Table 3 shows the numerical values ​​and evaluation results.

[0052] [Table 3]

[0053] The adhesive tapes and adhesive processed products of Examples 1 to 4 were adhesive tapes and adhesive processed products that had excellent appearance quality, adhesive workability, environmental friendliness, color uniformity inside and outside the adhesive joint, and release properties, by setting the stress at 50% elongation of the adhesive layer and release layer and the peel strength between the adhesive layer and release layer within preferred ranges.The adhesive tapes and adhesive processed products of Examples 1 and 2 were adhesive tapes and adhesive processed products that had even better visibility, by setting the visible light transmittance of the adhesive layer and release layer within preferred ranges. Furthermore, according to Example 3 and Figures 7 and 9, it was confirmed that adhesive processed products without wrinkles or distortions can be obtained by using an adhesive tape of the present invention having a curved adhesive part with a radius of curvature in the range of 5 cm to 30 cm and a tape width in the range of 5 mm to 30 mm.

[0054] The adhesive tape and adhesive processed product of Comparative Example 1 had a high stress at 50% elongation of the release layer, a high peel strength of the adhesive layer and release layer, and a high yield point stress of the adhesive tape, resulting in an adhesive tape and adhesive processed product with poor adhesive workability and releasability. The adhesive tape and adhesive processed product of Comparative Example 2 had low stress at 50% elongation in the adhesive layer and release layer, high visible light transmittance in the release layer, and a small radius of curvature in the adhesive part, resulting in an adhesive tape and adhesive processed product with poor visibility, adhesive workability, and releasability. The adhesive tape and adhesive processed product of Comparative Example 3 had a high stress at 50% elongation of the release layer and a high yield point stress of the adhesive tape, and low peel strength of the adhesive layer and release layer, a low visible light transmittance of the adhesive layer, and a wide adhesive tape, resulting in an adhesive tape and adhesive processed product that were inferior in appearance quality, adhesive workability, color uniformity inside and outside the adhesive area, and releasability. 7 to 10 show that compared to the adhesive sheet of Example 1, the adhesive processed product using the adhesive sheet of Comparative Example 3 had many wrinkles and was more likely to become distorted. The adhesive tape and adhesive processed product of Comparative Example 4 were subjected to molding and cutting to address the issues of appearance quality and adhesive workability of Comparative Example 3, which improved appearance quality and adhesive workability, but on the other hand, the waste rate increased, resulting in an adhesive tape and adhesive processed product that were less environmentally friendly. That is, the more requirements of the invention the adhesive tape and adhesive processed product satisfy, the more excellent the adhesive tape and adhesive processed product are overall. [Industrial Applicability]

[0055] The present invention can be used as an adhesive tape and adhesive processed products for clothing, miscellaneous goods, bedding, and industrial materials. [Explanation of symbols]

[0056] 1: adhesive tape 1a: Adhesive layer 1b: Release layer 2, 2': Adherent 3: Tape width 4: Adhesive part 5: Radius of curvature 6: Outer edge 7: Inner edge 8: Thickness 8a: Thickness at the outer edge 8b: Thickness at the inner edge 9: Adhesive processed products

Claims

1. An adhesive layer made of component A; a release layer comprising component B and covering one side of the adhesive layer; wherein the stress of the release layer at 50% elongation is in the range of 1 MPa to 25 MPa, the stress of the adhesive layer at 50% elongation is in the range of 1 MPa to 6 MPa, and the peel strength between the adhesive layer and the release layer is in the range of 0.05 N / cm to 0.5 N / cm.

2. 2. The adhesive tape of claim 1, wherein said component A is a thermoplastic hot melt.

3. The softening point T of the component B Ｂ１ is 100° C. or more, The softening point T Ａ１ is less than 100° C., Softening point ratio (T Ｂ１ / T Ａ１ 3. The adhesive tape according to claim 1, wherein the molecular weight of the adhesive tape is in the range of 2 to 5.

4. The melting point temperature T of the component A Ａ２ The melting point T of the component B is Ｂ２ High, Melting point temperature ratio (T Ｂ２ / T Ａ２ 4. The adhesive tape according to claim 1, wherein the saturation coefficient is in the range of 1.5 to 2.

5.

5. Visible light transmittance VT of component B Ｂ is 75% or less, Visible light transmission VT of the component A Ｂ The rate is 60% or more, Visible light transmittance ratio (VT Ｂ / V.T. Ａ 5. The adhesive tape according to claim 1, wherein the ratio of the thickness of the adhesive tape to the thickness of the adhesive tape is 80% or less.

6. Breaking strength BS of component B Ｂ is the breaking strength BS of the component A Ａ Higher, the ratio of breaking strength (BS Ｂ / BS Ａ 6. The adhesive tape according to claim 1, wherein the number of the groups is 1 or more.

7. The adhesive tape has a yield point elongation of 25% to 27%; The yield stress is 7 MPa to 16 MPa, 7. The adhesive tape according to claim 1, wherein the lower yield stress is from 7 MPa to 16 MPa.

8. An adhesive processed product using the adhesive tape according to any one of claims 1 to 7, The adhesive processed product has an adhesive part consisting of at least an adherend and an adhesive layer of the adhesive tape, The adhesive portion has at least a part of a curved shape with a radius of curvature in the range of 5 cm to 30 cm, The width of the adhesive tape is in the range of 5 mm to 30 mm; A bonded product, characterized in that the ratio of the maximum thickness to the minimum thickness (maximum thickness / minimum thickness) of the thickness at the outer edge portion in the longitudinal direction of the curved shape of the bonded portion to the thickness at the inner edge portion is in the range of 101 to 150%.

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