JP7271906B2 - Adhesive backing film, laminate, adhesive patch, and method for producing laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a film for a patch support, a laminate, an adhesive patch, and a method for producing a laminate.

In general, plastic films have properties such as being lightweight, chemically stable, easy to process, flexible and strong, and mass-producible. Therefore, plastic films are used for various purposes. Applications of plastic films include, for example, packaging materials for foodstuffs and pharmaceuticals, IV packs, shopping bags, posters, tapes, optical films used for liquid crystal televisions, protective films, and windows to be laminated on windows. A wide range of products, including films, plastic greenhouses, and construction materials. Appropriate plastic materials are selected for such applications depending on the application. Furthermore, a laminate is also made by stacking a plurality of types of plastic films. There is also a method of use in which a plurality of plastic materials are mixed in one layer to compensate for the shortcomings of a single material. In many cases, appropriate film materials are selected based on heat resistance, mechanical strength, or transparency.

In general, the mechanical properties and barrier properties of plastic films are determined by the material and layer structure. For example, plastic films tend to have low elongation when strength is emphasized, and there is a strong demand for film materials that can ensure sufficient elongation while having high strength. In addition, when barrier properties are required, it becomes necessary to use limited materials with good barrier properties, or to laminate a barrier layer in a separate process, resulting in labor and cost problems during manufacturing. may come.

By the way, a patch, which is typified by a patch to be stuck on the skin, contains a drug in an adhesive forming a surface to be stuck on the skin, and allows the drug to be absorbed into the body through the skin. The support constituting the outer surface of the patch is composed of a laminate of film or nonwoven fabric. Functions required for the backing of this patch include barrier properties against drugs (drug barrier properties) and elongation. The drug-barrier property is the ability of the backing to prevent or hardly absorb the drug so that the drug can be efficiently absorbed through the skin. The stretchability is an important factor such as suppressing the feeling of stiffness after sticking the patch to the skin and making it difficult for the pasted patch to come off during operation.

However, the current situation is that it is difficult to achieve both drug barrier properties and stretchability. In particular, materials for plastic films with drug barrier properties have been limited to some materials such as biaxially oriented PET (PolyEthylene Terephthalate), ethylene-vinyl alcohol copolymers, and cycloolefin copolymers. These materials have the disadvantage of low elongation due to their high strength.
For example, in Patent Document 1, a material such as PET or ethylene-vinyl alcohol copolymer is used as a backing for an adhesive patch. There is a drawback that it is easy to peel off during operation. As described above, conventionally, films for backing patches have been required to have both drug barrier properties and elongation properties.

In addition, films made of extensible materials (materials with high ductility) are difficult to handle, and if tension is applied during the manufacturing process or during use, the film will stretch, and the desired film required as a product may not be obtained. In addition, like ordinary films, the adhesive backing film also needs to be scratch and stain resistant.

Japanese Patent No. 6176846

The present invention has been made by focusing on the above points, and has molding stability that can suppress elongation and winding wrinkles during manufacturing, and supports good drug barrier properties and elongation during use. An object of the present invention is to provide a film for a patch support as a body, a laminate and a patch using the same.

In order to solve the problem, a first aspect of the present invention is a film for a patch support having a support layer on one side of which an adhesive layer can be arranged, wherein the support layer has a thickness of 5 μm. 150 μm or less, and the entire layer is configured in a shape that undulates in the thickness direction, so that it has an uneven structure that repeats concave portions and convex portions along the surface, and the uneven structure includes the concave portions and the convex portions. is greater than the thickness of the support layer, and a protective layer is detachably laminated on the one surface of the support layer or the other surface opposite to the one surface, and the support The gist is that the peel strength between the layer and the protective layer is 0.5 N/15 mm or less in a 180° peel test.

The adhesive backing film, which is an embodiment of the present invention, has molding stability capable of suppressing elongation during manufacture, and has a simple structure and good elongation properties when used.
In addition, according to the aspect of the present invention, by providing a peelable protective layer, there is also an effect of preventing the support layer from being damaged or soiled.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows an example in the film for patch support bodies of this embodiment. FIG. 2 is a schematic cross-sectional view showing an example of the adhesion state between the support layer and the protective layer in the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing a state in which the support layer and the protective layer are separated from each other in the adhesive patch support film of the present embodiment. FIG. 2 is a schematic cross-sectional view for explaining the film thickness, the height difference of the uneven structure, and the interval between the uneven structures in the film for an adhesive backing of the present embodiment. FIG. 4 is a schematic cross-sectional view for explaining the film thickness, the height difference of the uneven structure, and the interval between the uneven structures in a film for a patch support according to another embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 2 is a schematic cross-sectional view showing an example of changing the cross-sectional shape of the film for patch support of the present embodiment. FIG. 3 is a schematic bird's-eye view showing an example of the extending direction of the concave-convex structure in one section of the film for a patch support of the present embodiment. FIG. 4 is a schematic bird's-eye view showing another example of the extending direction of the uneven structure in one section of the film for a patch support of the present embodiment. FIG. 4 is a schematic bird's-eye view showing another example of the extending direction of the uneven structure in one section of the film for a patch support of the present embodiment. FIG. 4 is a schematic bird's-eye view showing another example of the extending direction of the uneven structure in one section of the film for a patch support of the present embodiment. FIG. 4 is a schematic bird's-eye view showing another example of the extending direction of the uneven structure in one section of the film for a patch support of the present embodiment. 1 is a graph showing examples of elongation behavior of a support film according to an embodiment of the present invention and a conventional support film. 2 is a graph showing the relationship between the total elongation of the film and the maximum value of local strain when the cross-sectional shape of the film for a patch support is changed. FIG. 3 is a cross-sectional view showing a film for a patch support with a different cross-sectional shape. It is a cross-sectional schematic diagram which shows the example of the laminated body which laminated|stacked another thermoplastic resin of this embodiment. FIG. 2 is a schematic cross-sectional view showing an example of a patch using a conventional film for a patch support. FIG. 2 is a schematic cross-sectional view showing an example of a patch using the laminate of the present embodiment. FIG. 3 is a schematic bird's-eye view showing an example of the extending direction of the concave-convex structure when a plurality of sections are combined in the film for a patch support of the present embodiment. FIG. 10 is a schematic bird's-eye view showing another example of the extension direction of the concave-convex structure when a plurality of sections are combined in the film for an adhesive backing of the present embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.
Each figure is a schematic diagram, and the size, shape, etc. of each part are appropriately exaggerated for easy understanding. In order to simplify the explanation, the same reference numerals are given to the corresponding parts in each figure.

(Structure of film for patch support)
As shown in FIG. 1, the film for patch support of this embodiment has a surface 2b side opposite to one surface 2a of the support layer 2 constituting the main body of the film for patch support 1 ( 1, lower surface side) has a peelable protective layer 3.
The support layer 2 is a layer in which a drug-containing pressure-sensitive adhesive layer 6 can be arranged on one surface 2a side (upper surface side in FIG. 1). The support layer 2 is made of a material having drug barrier properties against the drug contained in the pressure-sensitive adhesive layer 6 . The material of the support layer 2 may be appropriately selected from known plastic materials having drug barrier properties against drugs that are assumed to be used in patches.

Here, in the following description of the embodiments, mainly, as shown in FIG. 1, one surface 2a side (the upper surface side in FIG. 1) of the support layer 2 can be provided with a drug-containing adhesive layer 6. An example of a case where the surface is set as a flat surface will be described.
However, the present invention is not limited to the case where the surface opposite to the side on which the protective layer 3 is laminated as shown in FIG. 1 is the surface on which the adhesive layer 6 can be arranged. In FIG. 1, the present invention also includes the case where the peeling surface side (lower surface side in FIG. 1) of the support layer 2 after peeling the protective layer 3 is used as the surface on which the pressure-sensitive adhesive layer 6 can be placed.

Examples of materials for the support layer 2 include polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, polyacrylonitrile, ethylene-vinyl alcohol copolymer, and modified polymers thereof. When the patch is applied to the body, the medicinal ingredients contained in the adhesive layer 6 permeate the skin and act on the whole body through the blood. It is important that the adhesive backing film 1 used in such an adhesive patch serves as a barrier to the medicinal ingredients and does not or hardly adsorbs them. The above material has good barrier properties (non-adsorption properties) to the medicinal ingredients, and functions as a support without reducing the medicinal ingredients of the patch. When the support layer 2 is formed of such a material, it has drug barrier properties against drugs such as rivastigmine and tulobuterol.

As shown in FIG. 1, the support layer 2 of the present embodiment is configured such that the entire layer undulates in the thickness direction (meandering shape when viewed from the side), so that recesses 2A and recesses 2A are formed along the surface. It has a concavo-convex structure 4 that repeats the convex portions 2B. The uneven structure 4 is formed such that the height difference H between the concave portions 2A and the convex portions 2B is greater than the thickness of the support layer 2. As shown in FIG. The uneven structure 4 can be provided, for example, by processing the entire layer into a meandering shape along the surface direction.
Here, the support layer 2 may be composed of a plurality of layers. When the support layer 2 is composed of a plurality of layers, each layer may be composed of the same material, or may be composed of different materials.

The protective layer 3 is laminated on the other surface (lower surface in FIG. 1) of the support layer 2, which is the surface opposite to the surface on which the adhesive layer 6 is arranged.
Any material can be used for the protective layer 3, and the peel strength between the support layer 2 and the protective layer 3 and the dimensional stability in the manufacturing process should be taken into consideration when designing. As for the material of the protective layer 3, it is more preferable to use inexpensive materials such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, and polypropylene.
The protective layer 3 of the present embodiment has a flat back surface 3a (lower surface in FIG. 1) facing away from the support layer 2 . Flatness refers to having a flatness that is printable. The flatness of the protective layer 3 is preferably, for example, an arithmetic mean roughness (Ra) of 0.3 μm or less when observed with a laser microscope at a magnification of 200. Since the back surface is flat, wrinkles are less likely to occur during winding.

Further, in the present embodiment, the surface 3b of the protective layer 3 on the side of the support layer 2 has a shape along the shape of the surface of the concave-convex structure 4 on the side of the protective layer 3 . That is, the interface with the air of the support layer 2 (upper surface in FIG. 1) and the interface with the protective layer 3 are provided with an uneven shape, and the positions of the concave portions 2A and the convex portions 2B on the two surfaces are aligned. there is
FIG. 1 illustrates the case where the upper surface 3b of the protective layer 3 is formed in close contact with the lower surface 2b of the support layer 2 having the uneven structure 4. Between the support layer 2 and the protective layer 3, Voids may be formed. For example, the protective layer 3 may have a flat plate shape, and the upper surface 3b of the protective layer 3 may be configured so as to be in close contact only with the lower surface of the projections 2B of the uneven structure 4 in the support layer 2. FIG.

That is, in the patch support film 1 of the present embodiment, the protective layer 3 may enter deep into the projections of the support layer 2 as shown in FIG. As in c), there may be a partial gap 11 between the projections of the support layer 2 and the protective layer 3 . Preferably, the protective layer 3 penetrates deep into the projections of the support layer 2. Such a configuration is effective in suppressing elongation when tension is applied during the manufacturing process. be.
The peel strength between the support layer 2 and the protective layer 3 in a 180° peel test is 0.5 N/15 mm or less. The lower limit of the peel strength in the 180° peel test between the support layer 2 and the protective layer 3 is 0.01 N/15 mm.

In the adhesive patch support film 1 of the present embodiment, the protective layer 3 is peeled off from the support layer 2 as shown in FIG. After only a certain support layer 2 is taken out, another layer such as a functional layer is laminated on the support layer 2 . In such requirements, it is desirable that the interfacial peel strength between the support layer 2 and the protective layer 3 is 0.5 N/15 mm or less in a 180° peel test. By setting it as such peel strength, the support layer 2 and the protective layer 3 can be peeled comparatively easily. When it is desired to reduce the peel strength, it is preferable that there is a partial gap 11 between the projections of the support layer 2 and the protective layer 3, as shown in FIG. 2(b). By setting such a state, the contact area between the support layer 2 and the protective layer 3 can be reduced, and the peel strength can be reduced.

On the other hand, if the peel strength is less than 0.01 N/15 mm, the adhesion between the support layer 2 and the protective layer 3 is too poor. The dimensional stability of layer 2 may be compromised.
In addition, in the patch support film 1 of the present embodiment, it is preferable that the support layer 2 and the protective layer 3 are in close contact with each other directly without an adhesive or a pressure-sensitive adhesive interposed therebetween. Since no adhesive or pressure-sensitive adhesive is interposed, after the protective layer 3 is peeled off from the support layer 2 , there is no sticking residue (adhesive residue) of other components on the peeled surface of the support layer 2 . As a result, even after peeling, the function of the support layer 2 can be used without being impaired.

(Regarding uneven structure 4)
Regarding the concave-convex structure 4, the interval D1 between adjacent convex portions 2B and the interval D2 between adjacent concave portions 2A (see FIGS. 2 and 3) may be arranged with periodicity such as equal intervals. can be different. The intervals D1 and D2 can be appropriately set according to the desired stretched state required for the patch.
Further, as shown in FIGS. 1 to 12, the shape of the concave-convex structure 4 is a shape obtained by combining various straight lines and curved lines in cross-sectional views in the thickness direction. The same pattern may be used, or different patterns may be combined. The shape patterns shown in FIGS. 1 to 12 are reference examples, and the shapes are not limited to these.
In the concave-convex structure 4, at least one of the top portion 2Ba of at least one convex portion 2B of the plurality of convex portions 2B and the bottom portion 2Aa of at least one concave portion 2A of the plurality of concave portions 2A may have a flat cross-sectional shape.

FIGS. 1 and 9 illustrate the case where both the top portion 2Ba of the convex portion 2B and the bottom portion 2Aa of the concave portion 2A have a flat cross-sectional shape.
6 and 10 illustrate the case where the top 2Ba of the projection 2B has a flat cross section and the bottom 2Aa of the recess 2A has a V-shaped cross section.
7 and 11 illustrate the case where the top 2Ba of the projection 2B has a V-shaped cross section and the bottom 2Aa of the recess 2A has a flat cross section.
In the uneven structure 4, as shown in FIGS. 8 and 12, the tops 2Ba of the protrusions 2B and the bottoms 2Aa of the recesses 2A are each sharpened in the layer thickness direction to have a V-shaped cross section. , the concave-convex structure 4 may be formed to have a sawtooth cross section.

9 to 12 show examples in which the corners of the ridgeline portion (excluding the V-shaped cross-sectional portion), which is the boundary where the orientation of the surface is changed in the cross-section, are rounded.
In the concave-convex structure 4, the concave portions 2A and the convex portions 2B are arranged linearly as shown in FIGS. It may be configured with an extended concave-convex pattern. The concave portion 2A and the convex portion 2B may be configured to have the same width, or may be configured to have different widths.
FIG. 13 shows an example in which the region 10 for forming the concave-convex structure 4 has a rectangular shape bounded by sides 10a and 10b, and the extending directions of the concave portions 2A and the convex portions 2B are set so as to be parallel to the short side 10b. be. That is, this is an example in which the concave-convex structure 4 is formed such that the concave portions 2A and the convex portions 2B are arranged in the direction of the long side 10a of the region 10 along the surface direction.

FIG. 14 shows an example in which the region 10 for forming the uneven structure 4 is rectangular, and the extending directions of the concave portions 2A and the convex portions 2B are set to be inclined from both the short side 10b and the long side 10a.
15 to 17, the concave portions 2A and the convex portions 2B of the concave-convex structure 4 are formed as shown in FIGS. At least a part of the extending direction of 2B may be configured with a concavo-convex pattern configured with curved lines. The concave portion 2A and the convex portion 2B may be configured to have the same width, or may be configured to have different widths.
FIG. 15 shows an example in which the region 10 for forming the uneven structure 4 is rectangular, and the extending directions of the concave portions 2A and the convex portions 2B are set concentrically.

FIG. 16 shows an example in which the region 10 for forming the uneven structure 4 is rectangular, and the extending directions of the concave portions 2A and the convex portions 2B are concentric and elliptical (similar elliptical shapes).
In FIG. 17, the region 10 forming the concave-convex structure 4 has a rectangular shape, and the extending directions of the concave portions 2A and the convex portions 2B are set to be parallel to the short sides, and meandering along the extending direction. This is an example of setting to the state.
In addition, the above uneven pattern is an example, and is not limited to these shapes.
For example, in one region 10, the basic extending directions of the concave portion 2A and the convex portion 2B are linear, and a portion extending along a curved line is provided. may be set to a mixed pattern shape.

Moreover, although the rectangular shape was illustrated also about the area|region 10 which forms the uneven|corrugated structure 4, the shape of the area|region 10 is not limited to rectangular shape. The contour of the region 10 may be circular or the like.
Moreover, the entire surface of the support layer 2 does not need to be the area 10 where the uneven structure 4 is provided. For example, there may be portions where the uneven structure 4 is not formed, such as the edge portions on both the left and right sides in FIG. In the case of FIG. 13 , since the stretchability is increased in the left-right direction, there is no problem even if the support layer 2 partially lacks the uneven structure 4 as long as the stretchability is not constrained. .

(Thickness of patch support film 1, height of irregularities, etc.)
Further, the total thickness T of the adhesive backing film 1 at the position of the convex portion 2B is preferably, for example, 10 μm or more and 450 μm or less, more preferably 10 μm or more and 300 μm or less.
The thickness of the support layer 2 of the film 1 for patch support does not necessarily have to be uniform. In the film after the uneven shape processing, the thickness of the support layer 2 in the vicinity of the ridge line (near the connecting portion of the two portions facing in different directions) may be different from the thickness of the support layer 2 in other portions.
The thickness of the support layer 2 is preferably 5 μm to 150 μm, more preferably 10 μm to 100 μm.

The thickness of the protective layer 3 (thickness t3 at the concave portions 2A of the concave-convex structure 4, see FIGS. 4 and 5) is arbitrary, but the thickness t2 of the portion of the support layer 2 in close contact with the concave portions 2A is 5 μm to 150 μm. and more preferably 10 μm to 100 μm. If the thickness of the protective layer 3 is too thin, the effect of suppressing elongation and winding wrinkles in the manufacturing process may be insufficient. In some cases, peeling cannot be performed well due to insufficient stiffness. Moreover, if the thickness of the protective layer 3 is too thick, there is a problem that the manufacturing cost increases.

The height difference H between the concave portions 2A and the convex portions 2B of the concave-convex structure 4 is preferably in the range of 10 μm or more and 300 μm or less. If the height difference H between the concave portion 2A and the convex portion 2B is less than 10 μm, it may be difficult to obtain the effect of adjusting distortion. There is More preferably, the height difference H is within the range of 10 μm or more and 200 μm or less. It is assumed that the height difference H is thicker than the thickness of the protective layer 3 .
The concave-convex structure 4 is preferably a periodic structure in which concave portions 2A and convex portions 2B are regularly arranged. By avoiding an aperiodic structure, it is easy to obtain the intended elongation, and at the same time, the design and manufacture of the uneven structure 4 can be simplified. However, it is optional to change the width of the aperiodic concave-convex structure 4 or partially the concave-convex structure 4 .

(action and others)
The support layer 2 , which is the main body of the film for a patch support, is imparted with a required elongation by a unique structure having an uneven structure 4 . That is, since the support layer 2 alone is stretchable, the support layer 2 stretches more than necessary when tension is applied to the support layer 2 in the manufacturing process, and during operations such as winding, it becomes difficult to use the support layer as a patch support. In some cases, the film may be wrinkled or the film for a patch support may have unstable dimensions.
On the other hand, in the patch support film of the present embodiment, the protective layer 3 is laminated on the support layer 2 . Therefore, the protective layer 3 serves as a so-called support during the manufacturing process, thereby suppressing the elongation of the support layer 2 and contributing to suppression of winding wrinkles and dimensional stability.

In addition, the protective layer 3 protects the lower surface of the support layer 2 and functions to prevent the occurrence of scratches and the adhesion of dirt.
Here, when a film for an adhesive patch support (also referred to as a comparative film) is constructed from a flat plate-shaped support layer 2 that is not provided with an uneven structure 4 as in the present embodiment, the elongation behavior of the comparative film is represented by the reference numerals in FIG. As shown in 21, elastic deformation occurs only in a short distance after the film begins to stretch, and the yield point is soon reached (hereinafter, the starting point at which necking starts is called the yield point). After the yield point, plastic deformation accompanied by necking occurs, and when the breaking point is reached, the film breaks.

On the other hand, when the support layer 2 of the present embodiment is pulled, for example, in the left-right direction of FIG. plastic deformation occurs. If it is continued to be pulled further, the tensile stress reduces the height difference H of the uneven structure 4, and the uneven structure 4 approaches a flat shape, so that the shape cannot be deformed. In other words, the stage where the uneven structure is mainly crushed and spread (the area that stretches without applying much force) and the stage where the collapsed uneven structure is further stretched and becomes almost flat (the area that stretches when force is applied) are followed by the yield point. , and eventually necking occurs and breaks.

By performing such multistage shape deformation, the support layer 2 of the present embodiment has a higher yield point than the conventional patch support film, as indicated by reference numeral 21 in FIG. 18 . The amount of elongation increases and the stress required for elongation decreases. Therefore, the support layer 2 of the present embodiment contributes to the property of being easily stretched without necking.
Thus, even if the support layer 2 is made of a material generally considered to have low elongation, it is possible to impart high elongation to the support layer 2 by devising the shape. . In other words, the adhesive backing film (backing layer 2) after peeling off the protective layer 3 can achieve both strength and elongation.

At this time, by appropriately controlling the shape of the cross section of the support layer 2, any elongation can be obtained. For example, if it is desired to stretch the film greatly without breaking it, the height difference H between the ridges and valleys of the uneven structure 4 is increased, and adjustments are made such that the ridge line tops or ridge line troughs are not so rounded. Good.
After peeling off the protective layer 3 according to the present embodiment, the entire film for adhesive patch support is stretchable at the initial stage of stretching due to the change in the shape of the support layer 2 . can be improved. In other words, the film is stretched by plastically deforming and stretching the material itself from the initial stage of pulling, like a film for an adhesive backing having a normal flat surface. When the film for a patch support after peeling off the protective layer 3 according to the present embodiment is pulled in the direction in which the uneven structure 4 is arranged, local distortion occurs in the uneven structure 4 of the support layer 2 at the beginning of the pulling. (elongation and contraction) occurs, which changes the shape and collapses, so that a large elongation can be obtained with a weak stress. Therefore, by appropriately setting the shape of the concave-convex structure 4, the elongation of the entire film can be freely adjusted.

(Relationship between overall elongation of patch support film (support layer 2) after peeling off protective layer 3 and maximum value of local strain)
FIG. 19 shows the relationship between the total elongation and the maximum value of local strain when the shape of the uneven structure 4 of the support layer 2, which is the patch support film 1 after peeling off the protective layer 3, is changed. It shows the relationship. The vertical axis is the maximum value of local strain, and the horizontal axis is the elongation of the entire film. A flat plate-shaped support layer 2 having no uneven structure 4 indicated by dotted lines is used as a comparative example.
FIG. 20 shows the cross-sectional shape of the support layer 2 having high extensibility used for the evaluation shown in FIG. Shape A shown in FIG. 20A has a relatively large height difference H between recesses 2A and protrusions 2B of the uneven structure 4, and shape B shown in FIG. The height difference H of 2B is relatively small (however, it is made larger than the thickness of the support layer 2 to make the layer thicknesses equal). Further, it can be seen that the relationship between the overall elongation and the maximum value of local strain greatly changes depending on the difference in the uneven structure 4 of the support layer 2 having high elongation of the present embodiment.

For example, by making the height difference H between the concave portions 2A and the convex portions 2B of the concave-convex structure 4 relatively large as in the shape A in FIG. 20(a), as shown in FIG. Elongation can be less than local strain. In the patch support film 1 adopting the shape A, cracks such as rupture are less likely to occur in the film itself. In addition, for example, even if a hard functional layer is laminated on the surface (for example, deposition, hard coating, etc.) and pulled, the hard functional layer can be prevented from cracking. This is because the hard functional layer is loaded by the above-described local strain. That is, by applying the support layer 2 adopting the shape A to, for example, a layered body in which functional layers are laminated, it is possible to prevent breakage of the hard functional layers and to impart elongation.

In the shape B of FIG. 20(b), the height difference H between the concave portions 2A and the convex portions 2B of the concave-convex structure 4 is relatively small. In this case, as shown in FIG. There may be cases where the local distortion is greater than the However, the elongation of the film as a whole is large and exhibits high elongation compared to the unshaped film. These concave-convex structures 4 may be optimized in consideration of the desired extensibility and strength of the support layer 2 or the material and form of the functionalized layer to be laminated. For example, by optimizing using the general-purpose nonlinear finite element analysis solution Marc (registered trademark), it is possible to obtain the desired practical patch support film 1 .
Furthermore, in order to improve stretchability, the height difference H of the uneven structure 4 is the thickness of the support layer 2 (the average value of the thickness t1 of the top portion 2Ba of the convex portion 2B and the thickness t2 of the bottom portion 2Aa of the concave portion 2A, 4 and 5). By doing so, the cross section of the support layer 2 is less likely to be flat, and the strain adjustment effect can be effectively obtained.

(Characteristics of film 1 for patch support)
In addition, the film for a patch support (support layer 2) after peeling off the protective layer 3 having high elongation of the present embodiment has the effect of elongating when stress is applied. It also has a characteristic of high shock absorption when the structure 4 is crushed.
Furthermore, when the uneven structure 4 is a one-dimensional structure as shown in FIG. 1, there is also a property that the flexural rigidity is high in the direction in which the unevenness extends (in FIG. 1, the paper surface direction). Bending stiffness is determined by the integral of the product of the geometrical moment of inertia and Young's modulus. The adhesive backing film 1 of the present embodiment having high extensibility has a larger geometrical moment of inertia than a normal adhesive backing film 1 having the same amount of resin, so that the flexural rigidity is increased.
On the other hand, when the uneven structure 4 is a one-dimensional structure as shown in FIG. Flexural rigidity is improved accordingly. That is, since the rigidity and strength are improved in the manufacturing process before peeling off the protective layer, it contributes to preventing elongation in the manufacturing process and improving handling properties.

(Manufacturing method of film for patch support)
As for the method for producing the patch support film 1 of the present embodiment, for example, a method using hot press or a method using extrusion molding can be used.
In the hot press method, the multilayer film can be produced by passing it between heated rolls having an uneven surface on one side or through a heated flat press machine. At this time, by adjusting the press depth and press pressure, the interface between the support layer 2 and the air and the interface between the support layer 2 and the protective layer 3 are given an uneven shape, and the interface between the protective layer 3 and the air is substantially flat. Faces are preserved.
Alternatively, the film of the support layer 2 can be produced by passing the formed single-layer film through a press machine in which uneven shapes are provided on the front and back sides of the press and are precisely aligned, and in a subsequent step, the protective layer 3 is heated and pressed. is also possible.

In addition, in the extrusion molding method, a film having a multilayer structure of two or more layers can be obtained by co-extrusion of a plurality of types of different resins using a plurality of extruders by a feed block method or a multi-manifold method. can. In the cooling process for film formation, the uneven structure 4 can be formed by cooling while applying a nip pressure using a cooling roll having unevenness on the surface corresponding to the uneven structure 4 . At this time, when the height difference H between peaks and valleys of the uneven structure 4 is large with respect to the film thickness t of the support layer 2 in contact with the chill roll, the uneven structure 4 is added to the interface between the support layer 2 and the protective layer 3 as well. Therefore, it is possible to obtain a film in which the interface between the support layer 2 and the air and the interface between the protective layer 3 and the support layer 2 are uneven after cooling, and the interface between the protective layer 3 and the air is substantially flat.

Furthermore, in another method by extrusion, it can be produced using a tandem machine. That is, in the cooling step for extruding a single layer from one extruder in the first half and forming a film, a pair of cooling rolls provided with unevenness corresponding to the uneven structure 4 on the surface are used to reduce the nip pressure By cooling while adding , a single-layer support layer 2 having a concavo-convex structure 4 can be obtained. Then, in the latter half, a protective layer extruded from another extruder is laminated on the single-layer support layer 2 to obtain the adhesive patch support film 1 with a protective layer. At this time, the gap between the support layer 2 and the protective layer 3 can be appropriately adjusted depending on the process conditions, thereby adjusting the interfacial peel strength.
In addition, any method for adding the uneven structure 4, such as injection molding, can be selected, and the method is not particularly limited.

(Laminate)
A film for a patch support having a support layer 2 with high elongation can be printed on the outermost surface of the support layer 2 in a post-process, or on the release surface of the support layer 2 after the protective layer 3 has been removed from the support layer 2. It is also possible to form a laminate in which functional layers such as a vapor deposition layer, a hard coat layer, and an antireflection layer are laminated. Alternatively, a laminate can be formed by laminating another thermoplastic resin 31 or the like on the peeled surface of the support layer 2 after the protective layer 3 has been peeled from the support layer 2 (see FIG. 21). Another thermoplastic resin 31 constitutes the functional layer, for example as described above. FIG. 21 illustrates the case where the pressure-sensitive adhesive layer 6 is formed on another laminated thermoplastic resin 31 . Instead of another thermoplastic resin 31, the adhesive layer 6 may be provided directly.

FIG. 22 shows a schematic cross-sectional view of a common patch. In this general example, an adhesive layer 6 containing a drug is provided on one side of a film 8 for adhesive support, and a release liner 7 is provided on the surface of the adhesive layer 6 . When sticking to the skin, the release liner is peeled off and the pressure-sensitive adhesive layer 6 is stuck to the skin. Then, the drug contained in the adhesive layer 6 is absorbed through the skin and acts.
Such a general adhesive backing film 8 has insufficient extensibility, and the adhesive patch may feel stiff after being applied to the skin, and the lack of extensibility may cause the edge of the adhesive patch to be stretched during operation. There is a problem that such as may come off.

On the other hand, by using the film 1 for a patch support or the laminate of the present embodiment, it becomes possible to impart stretchability, and the aforementioned stiff feeling and peeling are eliminated.
As an example, FIG. 23 shows a cross-sectional view of an adhesive patch 9 using the adhesive adhesive support film 1 of the present embodiment. In this embodiment, by using a material with high drug barrier properties, the drug is effectively absorbed into the skin. Exhibits high elongation.
Here, in the patch support film 1 of the present embodiment, the support layer 2 after peeling off the protective layer 3 is used as a component of the patch. In consideration of this, FIGS. 21 and 23A illustrate the case where another thermoplastic resin 31 is arranged on the support layer 2. As shown in FIG.

(Another embodiment of film 1 for patch support)
As shown in FIGS. 24 and 25, the support layer 2 constituting the patch support film 1 has a plurality of regions 10, and each region 10 has an uneven structure 4 with an individual uneven pattern. You can do it.
24 and 25 show a series of adhesive backing films 1, in which a plurality of regions 10 (FIGS. 24 and 25 are examples of division into four regions 10) are set by dividing into a plurality of sections. , and the extending direction of the uneven structure 4 is indicated by a solid line. Reference numeral 10c indicates the boundary between adjacent boundary lines 10. FIG.

In FIG. 24, the extending direction of the concave-convex structure 4 is parallel to the edge of each section and orthogonal to the extending direction of the concave-convex structure 4 in the adjacent section. A film with good elongation has the problem that the film stretches during processing, making it difficult to form a stable film. By cutting or punching the product into sections, it is possible to provide the patch support film 1 that extends in a desired direction. There may be no clear boundaries between adjacent sections, and the number and size of sections existing on the series of film 1 for patch support can be set arbitrarily. Further, regions 10 having no concave-convex structure 4 may exist between the regions 10 .

The cutting position can also be arbitrarily set. For example, in the arrangement shown in FIG. It is possible to obtain the patch support film 1 for the partition. In this case, it is effective when one half of the film is to be fixed and only the remaining half is desired to be stretchable. That is, it may be designed such that a plurality of regions 10 constitute one final product. In this case, when the patch is to be applied to the skin, it is also possible to first apply and fix the non-stretchable half of the film to the skin and stretch the remaining half to apply.
In the patch support film 1 shown in FIG. 25, the angled uneven structure 4 extends straight from one side of each region 10 to the other side intersecting with the region 10 . Other configurations are the same as those of the adhesive backing film 1 shown in FIG. The angle of the uneven structure 4 with respect to the boundary line 10c that divides the regions 12 is arbitrary, and the angle may be different for each region 10 .

(Effect of this embodiment)
(1) A patch support film 1 of the present embodiment is a patch support film having a support layer 2 on one side of which an adhesive layer can be arranged. is 5 μm or more and 150 μm or less, and the entire layer is formed in a shape that undulates in the thickness direction, thereby having an uneven structure 4 in which concave portions and convex portions are repeated along the surface. is larger than the thickness of the support layer 2, and the protective layer 3 is detachably laminated on the other surface of the support layer 2, which is the surface opposite to the one surface of the support layer 2, so that the support layer 2 and the protection The peel strength with layer 3 is 0.5 N/15 mm or less in a 180° peel test.
According to this configuration, the adhesive backing film 1 after peeling of the protective layer has molding stability capable of suppressing elongation at the time of manufacturing and winding wrinkles, etc., and has both good drug barrier properties and elongation properties. can provide.

For example, in the patch support film 1 of the present embodiment, even if the support layer 2 is formed from a film having drug barrier properties, the elongation of the support layer 2 can be improved by providing the uneven structure 4 . . At this time, by providing the peelable protective layer 3 on the support layer 2, the above-mentioned elongation is ensured during use, and the adhesive film 1 can be easily applied during the manufacturing process and handling in the post-process. A required strength can be imparted to the agent support film 1 . That is, it is possible to impart molding stability to the adhesive backing film 1 capable of suppressing elongation in manufacturing processes such as winding.
Moreover, providing the peelable protective layer 3 also has the effect of preventing the support layer 2 from being scratched or soiled.

(2) In the patch support film 1 of the present embodiment, the surface 3b of the protective layer 3 on the support layer 2 side has a shape that conforms to the surface shape of the uneven structure 4 on the protective layer 3 side.
According to this configuration, while suppressing the peel strength between the protective layer 3 and the support layer 2 , the strength-imparting effect of the protective layer 3 can be achieved more reliably.
(3) In the patch support film 1 of the present embodiment, the back surface 3a, which is the surface of the protective layer 3 facing away from the support layer 2, is flat.
According to this configuration, since the back surface is flat, wrinkles are less likely to occur during winding than when the back surface is uneven on both sides.

(4) In the patch support film 1 of the present embodiment, the support layer 2 and the protective layer 3 can be directly peeled off without an adhesive or pressure-sensitive adhesive interposed between the support layer 2 and the protective layer 3. is adhered to.
According to this structure, the peeling surface of the support layer 2 after the protective layer 3 is peeled off does not leave any residue (adhesive residue) of other components. As a result, even after peeling, the function of the support layer 2 can be used without being impaired.
(5) In the patch support film 1 of the present embodiment, the material of the support layer 2 is polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, polyacrylonitrile, ethylene-vinyl alcohol copolymer, and modified polymers thereof. and coalescing.
According to this configuration, the support layer 2 can be provided with drug barrier properties.

(6) In the patch support film 1 of the present embodiment, one or more gaps are formed between the support layer 2 and the protective layer 3 .
According to this configuration, it becomes easy to set the peel strength between the support layer 2 and the protective layer 3 to be small by providing the gap.
(7) In the patch support film 1 of the present embodiment, the uneven structure 4 includes the top 2Ba of at least one of the plurality of protrusions 2B and the bottom of at least one of the plurality of recesses 2A. At least one of 2Aa has a flat cross-sectional shape.
According to this configuration, the adhesive patch support film 1 of the present embodiment can easily increase the amount of elongation up to the yield point, and is suitable for an adhesive patch support that requires greater elongation. In addition, the presence of the flat surface increases the contact area when laminating the drug-containing pressure-sensitive adhesive layer or the functional layer, resulting in good adhesion strength.

(8) In the adhesive patch support film 1 of the present embodiment, the concave-convex structure 4 has a V-shaped cross section in the layer thickness direction at the tops 2Ba of the convex portions 2B and the bottom portions 2Aa of the concave portions 2A.
According to this configuration, tear straightness is improved at the position of the V-shaped cross section, so when cutting to a desired size and using it, there is an advantage that it can be easily cut at any position of the V-shaped cross section. .
(9) In the patch support film 1 of the present embodiment, the concave portions and the convex portions each extend linearly in plan view.
According to this configuration, the elongation in the direction in which the unevenness is arranged can be reliably increased, and the bending rigidity in the direction in which the unevenness extends can be set high.

(10) In the patch support film 1 of the present embodiment, at least a part of the extending direction of the concave portion and the convex portion 2B is curved in plan view.
According to this configuration, the elongation in the direction in which the unevenness is arranged can be reliably increased, and the bending rigidity in the direction in which the unevenness extends can be set high.
In addition, by providing a curve in the extension direction in at least a part, for example, by forming a curve in consideration of the direction in which the body bends, it is possible to follow the change of the body at the position where it is attached. has the advantage of increasing

(11) In the patch support film 1 of the present embodiment, the height difference H of the unevenness is 10 μm or more and 300 μm or less.
According to this configuration, it is possible to reliably improve extensibility.
(12) In the adhesive patch support film 1 of the present embodiment, the irregularities are arranged periodically such as at regular intervals.
According to this configuration, it becomes easier to set the extensibility.
(13) In the adhesive patch support film 1 of the present embodiment, the irregular intervals are aperiodic.
According to this configuration, for example, by narrowing the pitch of the part where the body bends more and widening the pitch of the part where the body bends less, it is possible to control the elongation of the patch according to the movement of the body. For example, there is an advantage in that the followability is improved in parts of the body such as the joints and the vicinity of the shoulder blades where the sense of unevenness changes greatly.

(14) In the patch support film 1 of the present embodiment, the support layer 2 has a plurality of regions 10, and the uneven structure 4 is formed in each region 10 with an individual uneven pattern.
In this configuration, when used as the original film of the final product, the elongation of each region 10 is offset to some extent, and excessive elongation is suppressed, and when the film is managed in a roll shape or the like, the adhesive patch is used. The support film 1 can be easily handled.
In addition, when the film is used as the film 1 for the adhesive backing of the final product, it becomes easy to set two or more directions in which the film is easily stretched.

(15) A laminate may be formed by laminating a functional layer on the support layer 2 side of the film 1 for a patch support of the present embodiment.
According to this configuration, it is possible to provide a laminate having good extensibility.
(16) In the adhesive patch of the present embodiment, the adhesive layer 6 is laminated on one side of the support layer 2 in the adhesive backing film 1 or laminate, and the adhesive layer 6 is peeled off. A liner is formed.
According to this configuration, it is possible to provide an adhesive patch that has a simple structure, secures strength as a backing, and has both good drug barrier properties and elongation properties, while suppressing labor and cost in manufacturing.
Although the embodiments of the present invention have been exemplified above, it goes without saying that the present invention is not limited to the above embodiments. Moreover, it is arbitrary to combine and use the above embodiments.

Examples prepared by the present inventors will be described in detail below, but the present invention is not limited only to the following examples.
(Example 1)
As the material of the patch support film 1, the support layer 2 was cyclic olefin copolymer (COC) TOPAS 8007 (trade name) manufactured by Polyplastics Co., Ltd. Polystyrene (PS) HF77 (trade name) manufactured by PS Japan Co., Ltd. was used as the protective layer 3 . Then, the patch support film 1 is formed into a two-layer structure by extrusion molding by nipping the support layer 2 side with an uneven roll and the protective layer 3 side with a mirror surface roll having a substantially flat surface. was used as the sample of Example 1.
The support layer 2 had a thickness of 12 μm, the protective layer 3 had a thickness of 30 μm, and the uneven structure 4 had trapezoidal cross-sectional shapes arranged periodically. The height difference H of the trapezoidal uneven structure 4 was 31 μm, the pitch was 140 μm, the length of the upper side was 61 μm, and the length of the lower side was 68 μm.

(Example 2)
A sample of Example 2 was produced in the same manner as in Example 1, except that the cross-sectional shape was changed to a wavy shape with a height difference of 25 μm and a pitch of 50 μm.
(Example 3)
As the support layer 2, ethylene-vinyl alcohol copolymer (EVOH) Soarnol D2908 (trade name) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. was used. As the protective layer 3, low-density polyethylene (LDPE) Novatec LDLC701 (trade name) manufactured by Japan Polyethylene Co., Ltd. was used. The support layer 2 had a thickness of 30 μm, the protective layer 3 had a thickness of 45 μm, and the concave-convex structure 4 had trapezoidal cross-sectional shapes arranged periodically. The height difference H of the trapezoidal uneven structure 4 was 60 μm, the pitch was 255 μm, the length of the upper side was 205 μm, and the length of the lower side was 224 μm.
A sample of Example 3 was prepared in the same manner as in Example 1 except for the above.

(Example 4)
The thickness of the support layer 2 was 50 μm, the thickness of the protective layer 3 was 50 μm, and the uneven structure 4 was changed to a wavy cross-sectional shape with a height difference H of 100 μm and a pitch of 200 μm. 4 samples were made.
(Example 5)
The thickness of the support layer 2 was 125 μm, the thickness of the protective layer 3 was 50 μm, and the uneven structure 4 was changed to a wavy cross-sectional shape with a height difference H of 250 μm and a pitch of 500 μm. 5 samples were made.

(Example 6)
The thickness of the support layer 2 was 6 μm, the thickness of the protective layer 3 was 12 μm, and the uneven structure 4 was changed to a trapezoidal cross-sectional shape with a height difference of 31 μm, a pitch of 140 μm, an upper side length of 61 μm, and a lower side length of 68 μm. A sample of Example 6 was prepared in the same manner as in Example 3, except for the above.
(Example 7)
In Example 3, the thickness of the support layer 2 was 6 μm, the thickness of the protective layer 3 was 12 μm, and the concave-convex structure 4 was changed to a wavy cross-sectional shape with a height of 25 μm and a pitch of 50 μm. A sample of Example 7 was prepared by the method of.

(Comparative example 1)
At the time of extrusion molding, a mirror surface roll having no unevenness on the support layer 2 side was used to prepare a sample having no unevenness on the front and back sides. A sample of Comparative Example 1 was prepared in the same manner as in Example 1 except for the above.
(Comparative example 2)
A sample of Comparative Example 2 was prepared in the same manner as in Example 1, except that linear low-density polyethylene (LLDPE) Evolue SP2040 (trade name) manufactured by Prime Polymer Co., Ltd. was used as the protective layer 3 in Example 1. was made.

(Comparative Example 3)
At the time of extrusion molding, a mirror surface roll having no unevenness on the support layer 2 side was used to prepare a sample having no unevenness on the front and back sides. A sample of Comparative Example 3 was prepared in the same manner as in Example 3 except for the above.
(Comparative Example 4)
The support layer 2 has a thickness of 3 μm, the protective layer 3 has a thickness of 30 μm, and the uneven structure 4 has a trapezoidal cross-sectional shape with a height difference H of 31 μm, a pitch of 140 μm, an upper side length of 61 μm, and a lower side length of 68 μm. A sample of Comparative Example 4 was produced in the same manner as in Example 3, except for the change.

(Comparative Example 5)
A sample was prepared by extruding a single layer using only the support layer 2 without using the resin of the protective layer 3, and nipping with a pair of uneven rolls. The thickness of the support layer 2 was 12 μm, and the uneven structure 4 was changed to a trapezoidal cross-sectional shape with a height difference H of 31 μm, a pitch of 140 μm, an upper side length of 61 μm, and a lower side length of 68 μm. A sample of Comparative Example 5 was produced in the same manner.
(Comparative Example 6)
The thickness of the support layer 2 was 30 μm, and the uneven structure 4 was changed to a trapezoidal cross-sectional shape with a height difference H of 60 μm, a pitch of 255 μm, an upper side length of 205 μm, and a lower side length of 224 μm. A sample of Comparative Example 6 was produced in the same manner.

(Comparative Example 7)
The support layer 2 has a thickness of 50 μm, the protective layer 3 has a thickness of 30 μm, and the uneven structure 4 has a trapezoidal cross section with a height of 31 μm, a pitch of 140 μm, an upper side length of 61 μm and a lower side length of 68 μm. A sample of Comparative Example 7 was produced in the same manner as in Example 3, except for the change.
The resulting sample did not have a trapezoidal shape at the interface between the support layer 2 and the protective layer 3 .
(Comparative Example 8)
As the support layer 2, polylactic acid (PLA) Ingeo 3052D (trade name) manufactured by NatureWorks was used. As the protective layer 3, low-density polyethylene (LDPE) Novatec LDLC600A (trade name) manufactured by Japan Polyethylene Co., Ltd. was used. The support layer 2 had a thickness of 6 μm, the protective layer 3 had a thickness of 12 μm, and the concave-convex structure 4 had trapezoidal cross-sectional shapes arranged periodically. The height difference H of the trapezoidal uneven structure 4 was 31 μm, the pitch was 140 μm, the length of the upper side was 61 μm, and the length of the lower side was 68 μm.
A sample of Comparative Example 8 was prepared in the same manner as in Example 1 except for the above.

(Method for evaluating peel strength between support layer 2 and protective layer 3)
In order to evaluate the peel strength of the adhesive backing film 1 in each example and comparative example, a tensile test evaluation was performed.
Peel strength evaluation is based on JISK7127: 1999, using a Tensilon universal material tester (RTC-1250A) manufactured by A&D Co., Ltd., between the support layer 2 and the protective layer 3. Only the ends are peeled in advance. The sample was separately set on the upper and lower chucks, the support layer 2 and the protective layer 3 were separated from the zero state by 180°, and the average value of the section where the peel strength was stable was obtained.
As for the measurement conditions, the sample width was 15 mm, the distance between chucks was 50 mm, and the tensile speed was 100 mm/min. If the peel strength between the support layer 2 and the protective layer 3 is less than 0.3 N/15 mm, it is "○"; ×”.

(Molding processability evaluation method)
The moldability of the adhesive backing film 1 in each example and comparative example was evaluated.
Molding processability evaluation is mainly based on whether the film can be molded without defects in the stages from film formation to winding, and whether defects are observed in the appearance of the film sample after winding. We paid attention to and carried out visual judgment evaluation.
A case where there was no defect in molding processability was rated as "○", and a case where there was a defect was rated as "x".

(Elongation evaluation method)
In order to evaluate the elongation performance of the adhesive backing film 1 after peeling of the protective layer in each of the examples and comparative examples, a tensile test evaluation was performed.
The elongation evaluation is based on JISK7127: 1999, using a Tensilon Universal Material Testing Machine (RTC-1250A) manufactured by A&D Co., Ltd., while applying a tensile force from a zero state until the film breaks. It was carried out by determining the amount of elongation from the state to the yield point (hereinafter referred to as yield point elongation).
As for the measurement conditions, the sample width was 15 mm, the distance between chucks was 50 mm, and the tensile speed was 100 mm/min.
Yield point elongation was rated as "◯" when 20% or more, and as "x" when less than that.

(Drug adsorption evaluation method)
In order to evaluate the drug adsorption performance of the adhesive backing film 1 in each of Examples and Comparative Examples, adsorption test evaluation was performed.
After cutting the sample into 100 mm squares, a patch (Rivatouch patch 18 mg, manufactured by Ono Pharmaceutical Co., Ltd.) was attached to the center of the sample. It was sealed with aluminum foil so that the chemical would not volatilize and diffuse, and was stored in an environment of 40° C. and 75% for 6 months. Thereafter, the patch was peeled off from the film, the drug adsorbed on the film was extracted with methanol at 55°C for 3 hours or longer, and the amount of drug adsorption was measured using an ultra-high performance liquid chromatography 1260 HPLC system manufactured by Agilent Technologies. If the amount of drug adsorption was less than 10% of the amount of drug in the original patch, it was rated as "O", and if it was more than that, it was rated as "x".

Table 1 shows a list of conditions and evaluation results in each example. Table 2 shows a list of conditions and evaluation results in each comparative example.
In the table, the first layer means the supporting layer 2 and the second layer means the protective layer 3.

(Evaluation results)
As can be seen from Table 1, in Examples 1 to 7, in the two-layered film, the uneven structures 4 are provided extending in parallel at the interface between the support layer 2 and the air and the protective layer 3. Since the interface between the protective layer 3 and air is substantially flat, and the thickness of the support layer 2 is 5 to 150 μm, there is no problem during molding, and peeling can be performed with an appropriate peel strength during use. It can be seen that the support layer 2 after peeling has good yield point elongation and good drug adsorption.

On the other hand, in Comparative Examples 1 and 3 in Table 2, since both the support layer 2 and the protective layer 3 were flat films, the yield point elongation was small and the films did not stretch during use.
In Comparative Example 7, since the thickness of the support layer 2 is greater than the height difference H of the uneven structure 4, the interface between the support layer 2 and the protective layer 3 is flat. When used, the film had a low elongation at yield point and did not stretch.
In Comparative Example 2, since the COC resin was used as the support layer 2 and the LLDPE resin was used as the protective layer 3, the adhesion between the support layer 2 and the protective layer 3 was good, and the peel strength became too large, resulting in poor peeling. rice field.

In Comparative Example 4, the thickness of the support layer 2 was too thin at 3 μm, so that the stiffness of the film was low. rice field.
In Comparative Examples 5 and 6, only the support layer 2 was used to provide the uneven structure 4 on both the front and back sides of the film. Part of the structure collapsed, resulting in an inability to form a uniform film. In Comparative Example 8, since PLA was used as the material of the support layer 2, the drug barrier properties were poor and the results did not meet the requirements for a patch.

1 Adhesive Backing Film 2 Supporting Layer 2A Concave 2Aa Bottom 2B Convex 2Ba Top 3 Protective Layer 4 Concavo-convex Structure 6 Adhesive Layer 7 Release Liner 10 Area H Elevation Difference

Claims (17)

A film for a patch support having a support layer on one side of which an adhesive layer can be arranged,
The support layer has a film thickness of 5 μm or more and 150 μm or less, and has an uneven structure in which concave portions and convex portions are repeated along the surface by undulating the entire layer in the thickness direction,
In the uneven structure, the height difference between the recesses and the protrusions is greater than the thickness of the support layer,
A protective layer is detachably laminated on the other surface of the support layer opposite to the one surface,
The peel strength between the support layer and the protective layer is 0.5 N/15 mm or less in a 180° peel test,
A film for a patch support, wherein the support layer and the protective layer are directly and releasably adhered to each other without an adhesive or pressure-sensitive adhesive interposed between the support layer and the protective layer. . 2. The film for a patch support according to claim 1, wherein the surface of the protective layer on the support layer side has a shape that conforms to the shape of the surface of the uneven structure on the protective layer side. 3. The film for a patch support according to claim 1, wherein the back surface of the protective layer facing away from the support layer is flat. The material of the support layer is a resin selected from polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, polyacrylonitrile, ethylene-vinyl alcohol copolymer, and modified polymers thereof. The film for a patch support according to any one of claims 1 to 3 . 5. The film for a patch support according to any one of claims 1 to 4, wherein one or more voids are formed between the support layer and the protective layer. In the uneven structure, at least one of the top of at least one of the plurality of protrusions and the bottom of at least one of the plurality of recesses has a flat cross-sectional shape. The film for a patch support according to any one of claims 1 to 5 . The plaster support according to any one of claims 1 to 5 , wherein the uneven structure has a V-shaped cross section at the top of the protrusion and at the bottom of the recess. Film for. 7. The adhesive patch support according to any one of claims 1 to 6 , characterized in that, on the one surface side, the concave portion and the convex portion respectively extend linearly in plan view. body film. 8. The method according to any one of claims 1 to 7 , wherein at least a part of the extending direction of the concave portion and the convex portion on the one surface side is curved in a plan view. A film for a patch support as described. 10. The film for patch support according to any one of claims 1 to 9 , wherein the height difference is 10 µm or more and 300 µm or less. 11. The film for an adhesive patch support according to any one of claims 1 to 10 , wherein the arrangement of the concave portions and the convex portions has periodicity. 11. The film for an adhesive patch support according to any one of claims 1 to 10 , wherein the arrangement of the concave portions and the convex portions is aperiodic. The support layer according to any one of claims 1 to 11 , wherein the support layer has a plurality of regions, and the uneven structure is formed with an individual uneven pattern for each region. A film for adhesive backing. A laminate in which a functional layer is laminated on the support layer of the patch support film according to any one of claims 1 to 13 . In the adhesive backing film according to any one of claims 1 to 13 or the laminate according to claim 14 , a pressure-sensitive adhesive layer and a release liner are provided on one side of the support layer. A patch formed in sequence. In the patch support film according to any one of claims 1 to 1 to 3 , after peeling off the protective layer, a functional layer is formed on the peeling surface of the support layer on which the protective layer was laminated. A method for producing a laminate, characterized by laminating. 17. The method for producing a laminate according to claim 16 , wherein a pressure-sensitive adhesive layer and a release liner are formed in this order on one side of the support layer.

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