Thin film laminate, and method for manufacturing a thin film laminate

Abstract

To provide a thin film laminate that contains a water-soluble active ingredient in an amount sufficient for functional expression and does not impair an original function of a thin film.SOLUTION: There is provided a thin film laminate comprising a thin film containing a water-insoluble organic polymer material having a thickness of 10 nm or more and 5 μm or less, and a support base material that supports the thin film, in which the support base material has water permeability, and a water-soluble active ingredient is supported on the support base material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a transfer sheet comprising a thin film , and a method for manufacturing a thin film laminate. . Background Art

[0002] A thin film having a thickness of several micrometers or less exhibits high conformability to the surface shape of an adherend such as a living body's skin, and therefore adheres closely to the adherend even without using an adhesive or pressure-sensitive adhesive. It has been proposed to use such thin films in cosmetic applications such as skin care and makeup, and medical applications such as wound healing (see, for example, Patent Document 1).

[0003] Such a thin film is laminated with a support base material that supports the thin film, and by improving handleability, the thin film can be easily transferred to an adherend. When transferring a thin film to an adherend, it is common to use a process in which the support base material is peeled from the thin film laminate on the adherend using moisture, so that only the thin film remains on the adherend and is transferred. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2017-19116 Summary of the Invention Problems to be Solved by the Invention

[0005] When the thin film is used in cosmetic or medical applications, in addition to the emollient effect of the thin film itself, it is expected that additional functions can be added. For this reason, methods have been proposed in which active ingredients having any function, such as whitening ingredients and skin care ingredients, are added into the thin film.

[0006] However, because thin films exhibit high conformability and adhesion to the substrate due to their thinness, they have a very small volume. Consequently, there is a problem in that the amount of active ingredients that can be added must be very small. Increasing the amount of active ingredients added to thin films can lead to problems such as a decrease in the emollient effect of the thin film, the uniformity of the thin film material, and the uniformity of the film thickness and strength, resulting in the inability to obtain the desired effect.

[0007] The present invention has been made in view of the above circumstances, and provides a thin film laminate that contains a sufficient amount of water-soluble active ingredient for functional expression and does not impair the original function of the thin film. , and a method for manufacturing a thin film laminate. The objective is to provide this. [Means for solving the problem]

[0008] A thin film according to one aspect of the present invention is A thin film laminate comprising a thin film containing a water-insoluble organic polymer material having a thickness of 10 nm or more and 5 μm or less, and a support substrate for supporting the thin film, characterized in that the support substrate is permeable to water and a water-soluble active ingredient is supported on the support substrate.

[0009] According to the above configuration, the water-soluble active ingredient migrates from the support substrate to the adherend due to the moisture used when applying the thin film, making it possible to create a multi-functional and high-performance thin film. Furthermore, it is possible to load the amount of water-soluble active ingredient added to the thin film laminate.

[0010] In the above configuration, the mass ratio of the water-soluble active ingredient to the supporting substrate may be 0.01% or more and 5% or less. With the above configuration, it is possible to suitably obtain the effect of the active ingredient.

[0011] In the above configuration, the support substrate may be water-insoluble. With the above configuration, only the water-soluble active ingredient is transferred to the adherend by the moisture used when attaching the thin film, making it possible to efficiently bring the water-soluble active ingredient into contact with the adherend surface.

[0012] In the above configuration, the thin film may contain a biocompatible material. According to the above configuration, a thin film suitable for attachment to living organisms can be realized.

[0013] In the above configuration, the support substrate may include one or more selected from woven fabrics, nonwoven fabrics, paper, and mesh sheets. With the above configuration, it is possible to obtain suitable water permeability of the support substrate. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a thin film laminate that contains a sufficient amount of water-soluble active ingredient for functional expression and does not impair the original function of the thin film. [Brief explanation of the drawing]

[0015] [Figure 1] A diagram showing the cross-sectional structure of a thin film laminate in one embodiment of the present invention. [Modes for carrying out the invention]

[0016] An embodiment of a thin film laminate will be described with reference to the drawings.

[0017] [Basic structure of a thin film laminate] As shown in Figure 1, the thin film laminate 10 consists of a thin film 11 and a support substrate 12 on which a water-soluble active ingredient 13 is supported. The thin film 11 has a first surface 11f that is attached to the adherend and a second surface 11r that is opposite to the first surface 11f. The second surface 11r is the outermost surface located on the opposite side of the adherend when the thin film 11 is attached to the adherend.

[0018] The thin film 11 is thin enough to exhibit adhesiveness to an adherend when used alone. When the thickness of the thin film is 5 µm or less, good conformability of the thin film 11 to the surface shape of the adherend can be obtained, thereby enhancing the adhesion between the thin film 11 and the adherend. Furthermore, when the adherend is skin and the thickness is 5 µm or less, a user is less likely to feel an uncomfortable sensation such as the skin being pulled at the application site of the thin film 11.

[0019] Furthermore, the thickness of the thin film 11 is 10 nm or more. When the thickness is 10 nm or more, good strength of the thin film 11 can be obtained, so defects such as tearing are less likely to occur in the thin film 11. In addition, when the thickness is 10 nm or more, it is easy to form the thin film 11 into a continuous film shape.

[0020] As the water-insoluble polymer material constituting the thin film 11, known materials are used. Examples thereof include polyesters, polyolefins, polyamides, polyimides, polyvinyl alcohol, polyurethanes, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polycarbonates, acrylic resins, polysiloxanes, polysaccharides such as cellulose, chitin and chitosan, various proteins such as casein, rubber, and derivatives, modified products, copolymers and mixtures of these polymer compounds. The polymer material constituting the thin film may be selected and used appropriately in consideration of affinity with an arbitrary additive material and the adherend, physical properties such as film strength and elongation, and the like. Furthermore, when the adherend is a living body, the polymer material constituting the thin film 11 preferably has biocompatibility.

[0021] Furthermore, any optional additive can be added to the thin film 11 of the present invention. For example, when the adherend is a living body, it is possible to add fragrances, colorants, whitening components, ultraviolet and near-infrared shielding agents, cosmetic ingredients such as moisturizing components, antibacterial agents, preservatives and other pharmaceutical agents. However, it should be noted that as described above, additives added to the thin film 11 may affect the strength, elongation, moisture permeability and air permeability of the thin film in proportion to the addition amount per volume, and uniform addition may be difficult due to compatibility with the water-insoluble polymer, so there is a possibility that the addition amount may be limited.

[0022] The thin film 11 is formed by a known thin film formation method. For example, a melt extrusion method in which a molten material is extruded and molded into a thin film, or a solution casting method in which a solution of the material is applied in a thin film form onto a substrate and then the solvent is evaporated can be used. The formation method may be selected according to the material.

[0023] For example, when the solution casting method is used, a coating liquid is prepared by dissolving or dispersing the material of the thin film 11 in an appropriate solvent, and the coating liquid is applied onto a substrate made of resin or the like to form a coating film. A holding layer is formed when the coating film is solidified by drying. As the application method, various coating methods can be used, for example, direct gravure, reverse gravure, small-diameter reverse gravure, Meyer bar coating, die coating, curtain coating, spray coating, spin coating, screen printing, comma coating, knife coating, gravure offset, roll coating and the like.

[0024] The supporting substrate 12 has a function of suppressing deformation or tearing of the thin film 11 during storage of the thin film 11 and when moving the thin film 11 onto an adherend during use of the thin film 11. Being supported by the supporting substrate 12 makes the thin film 11 easier to handle. Furthermore, the supporting substrate 12 has a function of holding the water-soluble active ingredient 13 during storage.

[0025] The material of the support substrate 12 can be any known material. Preferably, the support substrate 12 contains one or more materials selected from woven fabrics, nonwoven fabrics, paper, and mesh sheets. Including the above materials provides suitable water permeability. Water permeability means that water can penetrate or pass through the support substrate 12. Including the above materials allows the water-soluble active ingredient 13 to be retained and also allows the water-soluble active ingredient 13 to be released by moisture during use.

[0026] The support base material 12, whether woven fabric, nonwoven fabric, or paper, is composed of natural or chemical fibers. Natural fibers may include cotton, linen, pulp, wool, silk, etc. Chemical fibers may include polyester, polyolefin, cupro, rayon, lyocell, acetate, diacetate, nylon, aramid, acrylic, etc. The support base material 21 may also be composed of a fibrous material mixed with natural and chemical fibers. Such a fibrous material support base material 21 may be subjected to processing such as embossing, perforation, or foaming to create porosity in the fibers.

[0027] When the support substrate 12 is a mesh sheet, examples of materials include polyester, polyolefin, polyamide, polyimide, polyvinyl alcohol, polyurethane, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, acrylic resin, polysiloxanes, cellulose, casein, and various other proteins, rubber, derivatives, modified forms, copolymers, and mixtures of these polymer compounds. The polymer film used as the support substrate 12 may be a film that has been processed by embossing, perforating, foaming, or other methods to create a porous structure.

[0028] If the support base material 12 is made of fibrous material, the basis weight of the support base material 12 is 3 g / m². 2 More than 200g / m 2 Preferably, it is 10 g / m 2 More than 100g / m 2The following is more preferable: If the basis weight of the support substrate 12 is equal to or greater than the above lower limit, the support substrate 12 will have sufficient rigidity to prevent deformation such as twisting caused by static electricity or airflow, making the thin film 11 easier to handle. In addition, the amount of water-soluble active ingredient 13 supported on the support substrate 12 will be sufficient to exhibit its function.

[0029] If the basis weight of the support substrate 12 is below the above upper limit, the fibers in the support substrate 12 will not become too densely packed. Therefore, when using a transfer method in which the support substrate 12 is moistened and the thin film 11 and support substrate 12 are separated, the liquid absorption of the support substrate 21 will proceed smoothly, and the transfer can be performed effectively.

[0030] The water-soluble active ingredient 13 supported on the support substrate 12 can be a known material having the desired function on the adherend. When the adherend is a living organism such as skin or tissue, it is possible to support any cosmetic or pharmaceutical ingredient for purposes such as whitening or moisturizing. For example, polysaccharides such as hyaluronic acid, acetylated hyaluronic acid, heparin, mucin, and β-glucan, proteins such as collagen, various amino acids, various vitamins, and derivatives of the above can be used.

[0031] Preferably, the mass ratio of the water-soluble active ingredient 13 to the support substrate 12 is 0.01% or more and 5% or less. More preferably, it is 0.01% or more and 3% or less. If the mass ratio is less than 0.01%, the amount of water-soluble active ingredient 13 that transfers to the adherend will be negligible, making it difficult to obtain a sufficient effect. If it exceeds 5%, the amount of water-soluble active ingredient 13 that transfers to the adherend will be excessive, and when the moisture on the surface of the adherend evaporates after application, the dried water-soluble active ingredient 13 will be visible as a powder on the adherend, which is undesirable in appearance. Furthermore, even after being supported on the support substrate 12, it is present in excess on the support substrate 12, so it easily detaches from the support substrate 12 and scatters as powder, which is undesirable in appearance.

[0032] Known methods can be used to support the water-soluble active ingredient 13 on the support substrate 12. For example, the support substrate 12 can be immersed in an aqueous solution containing the water-soluble active ingredient 13 and then dried, or it can be coated using various coating methods and then dried. Furthermore, the aqueous solution of the water-soluble active ingredient 13 can also consist of part or all of an alcohol as the solvent. The solvent should be appropriately selected and used considering the improvement of the drying properties of the solvent and the solubility of the water-soluble active ingredient 13 in the solvent.

[0033] Furthermore, the thin film laminate 10 may include a protective layer that covers the first surface 11f of the thin film 11. By including the protective layer, the thin film 11 is protected when the thin film laminate 10 is stored. As the protective layer, the various substrates described above as examples of support substrates 12 can be used. Note that the materials of the protective layer and the support substrate 12 may be the same or different.

[0034] The external shapes of the thin film 11 and the thin film laminate 10 in plan view are not particularly limited. The external shapes of the thin film 11 and the thin film laminate 10 may be, for example, polygonal shapes such as rectangles, circular shapes, elliptical shapes, or other shapes enclosed by straight lines or curves. In plan view, the shapes of the thin film 11 and the support base material 12 may be the same, or the support base material 12 may be larger than the thin film 11.

[0035] The thin film laminate 10 has a thin film 11 formed on a substrate for film formation as a supporting substrate. The thin film 11 may be formed by transfer onto the substrate 12, or by forming a thin film 11 on the support substrate 12. As for the method of transferring the thin film 11 from the substrate for film formation to the support substrate 12, any known transfer method may be used, such as a method that utilizes peeling by pressure or suction, or a method that utilizes a sacrificial film.

[0036] When using the thin film laminate 10, first, the thin film laminate 10 is placed on the adherend such that the adherend and the first surface 11f of the thin film 11 are in contact. Then, the support substrate 12 is peeled off from the thin film 11. This transfers the thin film 11 to the adherend.

[0037] A liquid such as water or lotion is supplied to the surface of the substrate before the thin film laminate 10 is attached, or to the support substrate 12 after the thin film laminate 10 is attached. By allowing the liquid to permeate the thin film laminate 10, the water-soluble active ingredient 13 supported on the support substrate 12 dissolves and migrates to the surface of the substrate. This also facilitates the peeling of the support substrate 12 from the thin film 11. To increase the amount of water-soluble active ingredient 13 transferred to the substrate, the thin film laminate 10 may be left to stand on the substrate for 5 to 15 minutes between the supply of the liquid and the peeling of the support substrate 12.

[0038] In this embodiment, since the thin film laminate 10 has the water-soluble active ingredient 13 supported on the support substrate 12, the effects of the water-soluble active ingredient 13 can be fully obtained without any practical physical limitations such as an upper limit on the amount to be added to the thin film 11 or a decrease in strength. [Examples]

[0039] The thin film laminate 10 described above will be explained using specific examples and comparative examples.

[0040] [Method for manufacturing thin film laminates] Poly-DL-lactic acid (manufactured by Musashino Scientific Research Institute Co., Ltd.) was dissolved in ethyl acetate, and the solid content was adjusted to 10%, which was used as the coating solution for forming the thin film according to the present invention. The weight-average molecular weight of the poly-DL-lactic acid used was 100,000.

[0041] The coating solution for forming the thin film described above was applied to a sheet of PET, which was the film-forming substrate, using a wire bar to form a coating film. The coating film was heated in an oven to dry and solidify, thereby forming a thin film on the film-forming substrate. The heating temperature for drying the coating film was 90°C for 1 minute. The thickness of the thin film was 550 nm.

[0042] Next, a nonwoven fabric made of pulp-based fibers was prepared as the support base material. The basis weight of the support base material was 50 g / m². 2 The following was determined: Sodium hyaluronate was selected as the water-soluble active ingredient, and the change in the stratum corneum moisture content was used as an indicator of effectiveness. The support substrate was immersed in a sodium hyaluronate aqueous solution of a desired concentration for 5 minutes, then removed and allowed to stand until the sodium hyaluronate aqueous solution no longer dripped. Furthermore, the support substrate containing the sodium hyaluronate aqueous solution was dried at 70°C for 30 minutes to remove moisture, thereby loading sodium hyaluronate onto the support substrate.

[0043] Next, the support substrate carrying the sodium hyaluronate was placed on top of a thin film on a film-forming substrate, and the laminate of the film-forming substrate, thin film, and support substrate was pressed with a rubber roller from the side where the film-forming substrate was located, while peeling off the film-forming substrate.

[0044] In the above manufacturing method, by changing the concentration of the sodium hyaluronate aqueous solution, different mass ratios of the support substrate and the water-soluble active ingredient (the proportion of the water-soluble active ingredient supported on the support substrate) can be obtained. Thin film laminates were formed according to Examples 1-5 and Comparative Examples 1-2.

[0045] <Evaluation Method> (Appearance evaluation 1) For each of Examples 1-5 and Comparative Examples 1-2, five samples were prepared. For each sample, it was checked whether there was any easily visible precipitation of sodium hyaluronate on the thin film laminate, particularly on the surface of the support substrate, or whether sodium hyaluronate was removed by light pressure from a finger. For all five samples, those in which no easily visible precipitation of sodium hyaluronate (hereinafter referred to as precipitation) or removal of sodium hyaluronate by light pressure from a finger (hereinafter referred to as removal) was observed were marked with "○", those in which no precipitation or removal was observed for three or four samples were marked with "△", and those in which no precipitation or removal was observed for two or fewer samples were marked with "×".

[0046] (Appearance evaluation 2) 500 μl of water was supplied to the inner skin of a human forearm as the adherend, and the supplied water was gently spread with a finger. Then, the thin film laminate of the sample was placed on the skin so that the thin film was in contact with the skin. Next, the sample was pressed with a finger from above the support substrate for 3 seconds. After standing for 10 minutes, the support substrate was peeled off from the edge of the sample with a finger. As a result, the thin film was adhered to the skin.

[0047] After application, participants went about their daily lives, and after 6 hours, the appearance was visually inspected. For all five samples, those showing no precipitation were marked with "○", those showing no precipitation in three or four samples were marked with "△", and those showing no precipitation in two or fewer samples were marked with "×".

[0048] (Evaluation of moisturizing function) For each example and comparative example, a sample was prepared by cutting the transfer sheet into a circular shape with a diameter of 40 mm. Then, for each sample, the thin film laminate was applied to human skin according to the following procedures (1) to (4), and the moisturizing function was evaluated.

[0049] (1) The forearm of the subject is designated as the test site. After washing the test site with water, the water is wiped off and left for 20 minutes. (2) The stratum corneum moisture content of the test site is measured using a skin characteristics evaluation device (Integral Co., Ltd., Conurage-Khazaka Corneometer CM825). The measured value is taken as the initial stratum corneum moisture content.

[0050] (3) 500 μL of water is supplied to the test site. Then, the sample is left to stand for 15 minutes. Next, the thin film is attached to the test site by peeling off the support substrate.

[0051] (4) After 6 hours have elapsed since the operation in (3) above, the thin film is peeled off the test area. Then, the stratum corneum moisture content is measured at each of the areas where the thin film was applied using the skin characteristic evaluation device described above. Each of the measured stratum corneum moisture content is compared with the initial stratum corneum moisture content described above, and the increase in stratum corneum moisture content from the initial stratum corneum moisture content is determined. For the operations in (1) to (4) above, an area where the thin film laminate was not applied was provided, and the stratum corneum moisture content was measured in the same way as at the area where the sample was applied, and this was referred to as Reference Example 1.

[0052] In evaluating the moisturizing function, a "○" was used if the amount of moisture in the stratum corneum increased before and after the application of the sample, and a "×" was used if there was no change in the increase in the amount of moisture in the stratum corneum between the areas where the sample was not applied and the areas where the sample was applied, or if it decreased.

[0053] <Evaluation Results> Table 1 shows the loading ratio of sodium hyaluronate in the support substrate, as well as the appearance of the thin film laminate before application, the appearance of the application site 6 hours after the thin film is applied to the skin, the moisturizing effect, and the overall evaluation. The overall evaluation is as follows: "○" if all evaluations are "○", "△" if none of the evaluations are "×" but some are "△", and "×" if any of the evaluations are "×".

[0054] [Table 1]

[0055] As shown in Table 1, an increase in stratum corneum moisture content was observed in Examples 1 to 5, and the appearance of the thin film laminate before application and the appearance 6 hours after application were also good.

[0056] In Comparative Example 1, since it did not contain an aqueous solution of sodium hyaluronate as a water-soluble active ingredient, no increase in stratum corneum moisture content was observed. In Comparative Example 2, the amount of active ingredient was excessive, resulting in precipitation and detachment, and unsatisfactory results were not obtained.

[0057] In Reference Example 1, no change in stratum corneum moisture content was observed in the areas where the thin film laminate was not applied, and it can be concluded that there was no environmental influence.

[0058] From the above examples and comparative examples, it is possible to provide a new thin film laminate with virtually no limitations on the amount of water-soluble active ingredient that can be incorporated according to the present invention. In this case, sodium hyaluronate was selected as the water-soluble active ingredient and the stratum corneum moisture content was used as an indicator, but in principle, the same effects can be obtained with other water-soluble active ingredients as mentioned above. When evaluating, an indicator corresponding to each effect should be used. [Explanation of symbols]

[0059] 10…Thin film laminate 11…Thin film 11r…Side 1 11f…Second side 12...Supporting base material 13…Water-soluble active ingredients

Claims

1. A thin film containing a water-insoluble organic polymer material having a thickness of 10 nm to 5 μm, A thin film laminate comprising a support substrate that is in contact with the thin film and supports the thin film, The support substrate is permeable to water, and a water-soluble active ingredient is supported inside the support substrate, which is released from the support substrate by moisture when the thin film is used. The mass ratio of the water-soluble active ingredient to the support substrate is 0.01% or more and 5% or less. The support substrate is water-insoluble. A thin film laminate characterized by the following features.

2. The thin film laminate according to claim 1, characterized in that the thin film contains a biocompatible material.

3. The thin film laminate according to claim 1 or 2, characterized in that the support substrate includes one or more selected from woven fabrics, nonwoven fabrics, paper, and mesh sheets.

4. Immersing a water-permeable and water-insoluble support substrate in an aqueous solution containing a water-soluble active ingredient, The immersed support substrate is dried to remove moisture. This includes superimposing a thin film containing a water-insoluble organic polymer material having a thickness of 10 nm to 5 μm onto the dried support substrate, Immersing the support substrate includes supporting the water-soluble active ingredient inside the support substrate such that the mass ratio of the water-soluble active ingredient to the support substrate is 0.01% or more and 5% or less. A method for manufacturing a thin film laminate.

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