Protective film for clothing, protective sheet, strip for protective film for clothing, method for protecting clothing, and application device

Abstract

To provide a protective film which has an advantage for properly protecting goods while keeping its low visibility.SOLUTION: A protective film 10a comprises regenerated cellulose and a low refractive material having refractive index less than 1.55, and has thickness from 100 nm or more to 2,000 nm or less. The regenerated cellulose may have a weight average molecular weight of 100,000 or greater, while the low refractive material may have a SP value from 20 MPa1 / 2 or more to 25 MPa1 / 2 or less. The low refractive material may contain polymer which is selected from a group including polymethyl methacrylate, polybutyl methacrylate and polyvinylidene fluoride.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to protective films, protective sheets, protective film strips, methods for protecting articles, and mounting devices. [Background technology]

[0002] BACKGROUND ART Conventionally, techniques for protecting articles such as clothing are known.

[0003] For example, Patent Document 1 describes a film to be attached to articles such as clothing. This film is made of a transparent or translucent polyurethane elastomer film and has an adhesive layer on the back surface. The thickness of this film is 20 μm or more and 50 μm or less.

[0004] Patent Document 2 describes an antireflection film having a low refractive index layer, which has a refractive index lower than that of a support made of cellulose acylate and has a thickness of 10 μm to 70 μm, directly or via another layer on the support. This antireflection film can function as a protective film for a polarizing plate in a liquid crystal display device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-69038 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-182004 Summary of the Invention [Problem to be solved by the invention]

[0006] The techniques described in Patent Documents 1 and 2 need to be reconsidered from the viewpoint of appropriately protecting an article while maintaining low visibility. Therefore, the present disclosure provides a protective film that is advantageous from the viewpoint of appropriately protecting an article while maintaining low visibility. [Means for solving the problem]

[0007] The present disclosure provides: Regenerated cellulose, a low refractive index material having a refractive index less than 1.55; having a thickness of 100 nm or more and 2000 nm or less; Provides a protective coating.

[0008] Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and / or advantages are provided individually by the various embodiments or features disclosed in the specification and drawings, and not all are required to obtain one or more of them. [Effects of the Invention]

[0009] The above-mentioned protective film is advantageous from the viewpoint of adequately protecting the article while maintaining low visibility. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an example of a protective film according to the present disclosure. [Figure 2A] FIG. 2A is a diagram showing an example of a method for applying the protective film of the present disclosure. [Figure 2B] FIG. 2B is a diagram showing an example of a method for applying the protective film of the present disclosure. [Figure 2C] FIG. 2C is a diagram showing an example of a method for applying the protective film of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view schematically illustrating an example of a protective sheet according to the present disclosure. [Figure 4] FIG. 4 is a diagram schematically illustrating an example of a protective film strip according to the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating an example of the mounting device of the present disclosure. [Figure 6] FIG. 6 is a diagram showing another example of the wearing device of the present disclosure. [Figure 7] FIG. 7 is a diagram showing yet another example of the wearing device of the present disclosure. [Figure 8]FIG. 8 is a cross-sectional view schematically showing another example of the protective film of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Findings that formed the basis of this disclosure) The thickness of the film described in Patent Document 1 is 20 μm or more and 50 μm or less, so this film is easily visible. In addition, this film is a polyurethane elastomer film, so it is thought that it is difficult for moisture such as sweat to pass through and is prone to causing stuffiness.

[0012] The anti-reflection film described in Patent Document 2 is easily visible because it has a support with a thickness of 10 μm to 70 μm. In addition, cellulose acylate is a hydrophobic material, and is therefore thought to be compatible with sebum.

[0013] Therefore, the present inventors have been researching and developing a technology that can adequately protect articles by maintaining low visibility while allowing moisture to easily pass through and suppressing stains such as sebum, etc. As a result, the present inventors have newly discovered that a protective film containing regenerated cellulose and a low refractive index material and having a predetermined thickness is advantageous, and have devised the protective film of the present disclosure.

[0014] (Embodiment) Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments are merely examples, and the protective film of the present disclosure is not limited to the following embodiments. The numerical values, shapes, materials, components, component arrangements and connection forms, steps, and step orders shown in the following embodiments are merely examples and are not intended to limit the present disclosure. The following various embodiments can be combined with each other as long as no contradiction occurs. Furthermore, among the components in the following embodiments, components not recited in the independent claims representing the highest concepts should not be understood as essential components. In the following description, components having substantially the same functions are denoted by common reference symbols, and their description may be omitted. Furthermore, to avoid overly complicated drawings, some elements may be omitted from the illustration.

[0015] As shown in FIG. 1, the protective film 10a contains regenerated cellulose and a low refractive index material having a refractive index of less than 1.55. The protective film 10a has a thickness of 100 nm or more and 2000 nm or less. In this specification, the refractive index is the value (n D 20 ) The refractive index can be measured, for example, in accordance with Japanese Industrial Standards (JIS) K 0062-1992. The thickness of the protective film 10a can be determined, for example, by measuring the thickness of the protective film 10a at multiple locations and averaging the measured values. The thickness at each location can be measured, for example, using a stylus profiling system (manufactured by Bruker Nano Inc., product name: DEKTAK (registered trademark)).

[0016] The protective film 10a has a thickness of 100 nm or more and 2000 nm or less. Therefore, light easily passes through the protective film 10a, making the protective film 10a difficult to see. The refractive index of cellulose is typically 1.55. Therefore, the low refractive index material has a refractive index lower than that of cellulose. In the protective film 10a, the low refractive index material suppresses light scattering, making the protective film 10a difficult to see.

[0017] The protective film 10a contains regenerated cellulose, and therefore can adequately protect the article from dirt such as sebum and is easily permeable to moisture.

[0018] Regenerated cellulose is, for example, cellulose substantially represented by the following formula (I). Here, "cellulose substantially represented by formula (I)" refers to cellulose in which 90% or more of the hydroxyl groups of the glucose residues in the cellulose represented by formula (I) remain. The ratio of the number of hydroxyl groups of the glucose residues in the cellulose contained in the membrane to the number of hydroxyl groups of the glucose residues in the cellulose represented by formula (I) can be quantified by a known method such as X-ray photoelectron spectroscopy (XPS). Note that the cellulose contained in the membrane may contain a branched structure in some cases. Artificially derivatized cellulose typically does not fall under "cellulose substantially represented by formula (I)." On the other hand, "cellulose substantially represented by formula (I)" does not exclude cellulose regenerated via derivatization. Even cellulose regenerated via derivatization may fall under "cellulose substantially represented by formula (I)."

[0019] [ka]

[0020] Cellulose has a molecular structure containing many hydroxyl groups. In films composed of cellulose, many hydrogen bonds are likely to form within or between molecules. Therefore, films composed of cellulose tend to have higher strength than films composed of other organic polymers. However, the strength of films formed from suspensions of natural cellulose fibers dispersed in a dispersant such as water is mediated by hydrogen bonds between the nanofibers that make up the cellulose fibers. Therefore, such films have room for further improvement in strength. On the other hand, in films composed of regenerated cellulose, the nanofibers are disaggregated down to molecular chain units, so the strength of films composed of regenerated cellulose is mediated by hydrogen bonds between cellulose molecular chains. In films composed of regenerated cellulose, hydrogen bonds are likely to form between units smaller than nanofibers. Therefore, films composed of regenerated cellulose have higher strength and moderate flexibility than films formed from suspensions of natural cellulose fibers dispersed in a dispersant such as water. Therefore, the protective film 10a containing regenerated cellulose is tear-resistant and easy to handle, despite its thickness of 100 nm to 2000 nm. "Nanofibers" are also called "nanofibrils or microfibrils," and are the most basic unit formed by the assembly of cellulose molecules, with a diameter of approximately 4 nm to approximately 100 nm and a length of approximately 1 μm or more.

[0021] Regenerated cellulose has a weight-average molecular weight of, for example, 100,000 or more. This is advantageous from the perspective of increasing the strength of the protective film 10a. This is because, in addition to increasing the strength along the direction of extension of the molecular chain, the number of hydroxyl groups contained per molecular chain is thought to increase the strength of the protective film 10a by forming more hydrogen bonds between molecules. The weight-average molecular weight of regenerated cellulose can be determined, for example, by gel permeation chromatography (GPC). A sample for GPC measurement can be prepared, for example, by extracting components other than regenerated cellulose from the protective film 10a.

[0022] As used herein, "regenerated cellulose" refers to cellulose that does not have the crystalline structure I characteristic of native cellulose. The crystalline structure of cellulose can be confirmed by its XRD pattern. In an XRD pattern using CuKα radiation, native cellulose exhibits peaks near 14-17° and 23°, which are characteristic of crystalline structure I. However, regenerated cellulose often exhibits crystalline structure II, which exhibits peaks near 12°, 20°, and 22°, but does not exhibit peaks near 14-17° and 23°.

[0023] For example, 90% or more by mass of the regenerated cellulose contained in the protective film 10a may be regenerated cellulose that has not been chemically modified or derivatized. 98% or more by mass of the regenerated cellulose contained in the protective film 10a may be regenerated cellulose that has not been chemically modified or derivatized. In this case, the protective film 10a contains a large amount of regenerated cellulose that has not been chemically modified or derivatized, and it is believed that more hydroxyl groups are contained per cellulose molecular chain. This is thought to result in more hydrogen bonds being formed between cellulose molecules, making the protective film 10a more likely to have high strength. The regenerated cellulose contained in the protective film 10a may be uncrosslinked.

[0024] As described above, the protective film 10a has a thickness of 100 nm or more and 2000 nm or less. If the thickness of the protective film 10a is 20 nm or more, the protective film 10a has high strength and is easy to handle. Therefore, the protective film 10a can function as a self-supporting film that can be attached to an article. If the thickness of the protective film 10a is 2000 nm or less, the protective film 10a is less likely to peel off when attached to an article.

[0025] The protective film 10a preferably has a thickness of 100 nm or more and 1000 nm or less. If the thickness of the protective film 10a is 100 nm or more, the protective film 10a has higher strength and is less likely to lose light transmittance. If the thickness of the protective film 10a is 1000 nm or less, light can more easily transmit through the protective film 10a, and the protective film 10a is less visible.

[0026] The low refractive index material is not limited to a specific material as long as it has a refractive index of less than 1.55. The low refractive index material may be an inorganic material such as a metal, an organic material, or a hybrid material of an inorganic material and an organic material. Examples of low refractive index materials include magnesium fluoride, lithium fluoride, calcium fluoride, silicon dioxide, sodium chloride, potassium dihydrogen phosphate, calcium carbonate, hydrated lime, fluororubber, silicone rubber, vinylidene fluoride, silicone resin, acrylic rubber, polypropylene rubber, ethylene propylene rubber, urethane, acrylic resin, polymethacrylic acid, polymethacrylic acid derivatives, urethane rubber, butyl rubber, natural rubber, nitrile rubber, polyethylene rubber, polyamide resin, nylon, styrene butadiene rubber, and MBS resin. Examples of low refractive index materials include vinyl chloride, Canada balsam, silver, gold, copper, duralumin, aluminum, fluorite, glass, opal, stilbite, moldavite, lapis lazuli, moonstone, chalcedony, chrysoprase, carnelian, jasper, tiger's eye, sunstone, amazonite, asbestos, granite, agate, onyx, crystal, silica, hollow silica, fluorinated polymers such as polyvinylidene fluoride, polymethyl methacrylate, polybutyl methacrylate, Teflon, and Teflon AF. Teflon is a registered trademark. The protective film 10a may contain one type of low refractive index material, or two or more types of low refractive index materials.

[0027] Low refractive index material: 20 MPa 1 / 2 More than 25MPa 1 / 2 The low refractive index material may have an SP value of 20 MPa or less. 1 / 2 If the SP value of the low refractive index material is 25 MPa or more, the low refractive index material is easily compatible with the regenerated cellulose, and the protective film 10a can be easily produced. 1 / 2 If the SP value is equal to or less than this, the inductive force that constitutes the SP value becomes relatively small, and light scattering is less likely to occur in protective film 10a, which allows light to more easily pass through protective film 10a and makes protective film 10a less visible.

[0028] The low refractive index material preferably includes a polymer, which is easily dissolved in a solvent and can be easily incorporated into the protective film 10a.

[0029] The low refractive index polymer preferably includes at least one selected from the group consisting of polymethyl methacrylate, polybutyl methacrylate, and polyvinylidene fluoride. These materials are easily soluble in aprotic polar solvents, making it easy to form the protective film 10a.

[0030] The content of the low refractive index material in the protective film 10a is not limited to a specific value. The content is, for example, 0.1% to 50% by mass. If the content of the low refractive index material is 0.1% or more by mass, the scattered light in the low refractive index material and the scattered light in the regenerated cellulose tend to cancel each other out, making the protective film 10a difficult to see. If the content of the low refractive index material is 50% or less by mass, the low refractive index material and the cellulose interact appropriately, making the protective film 10a easy to handle.

[0031] 1, the protective film 10a has a structure 11 containing, for example, regenerated cellulose. A low refractive index material is dispersed in the structure 11. In this case, the apparent refractive index of the protective film 10a decreases, and the scattered light intensity decreases, making the protective film 10a less visible. The structure 11 may be configured as a composite material of regenerated cellulose and a low refractive index material.

[0032] The protective film 10a may further contain a pressure sensitive adhesive or adhesive, which makes it easier to attach the protective film 10a to the item to be protected.

[0033] The pressure-sensitive adhesive or adhesive may be soluble or dispersible in water, for example. In this case, the protective film 10a can be peeled off from the object to be protected using water. For example, the protective film 10a can be peeled off from the object to be protected using running water.

[0034] The pressure-sensitive adhesive and adhesive have a glass transition temperature of, for example, 0° C. or higher. In this case, the pressure-sensitive adhesive and adhesive tend to become rubbery at room temperature, making it easy to attach the protective film 10a to the object to be protected.

[0035] The pressure sensitive adhesive and adhesive are, for example, 15 MPa. 1 / 2 More than 25MPa 1 / 2 The SP value of the adhesive and adhesive is 15 MPa. 1 / 2 By satisfying the above conditions, the adhesive and the pressure sensitive adhesive are easily compatible with the regenerated cellulose, and the protective film 10a can be easily produced. 1 / 2 By satisfying the following conditions, the protective film 10a can be easily attached not only when the surface of the article to be protected is made of a hydrophilic material, but also when the surface is made of a hydrophobic material. In addition, the pressure-sensitive adhesive and adhesive are easily dispersed in solvents such as water and ethanol, making it easy to prepare the protective film 10a.

[0036] A tape having an adhesive surface formed by a pressure-sensitive adhesive or adhesive is produced, and the pressure-sensitive adhesive or adhesive tape satisfies, for example, the following conditions (i), (ii), and (iii): (i) The tape peel adhesive strength, determined in accordance with Method 1 of JIS Z 0237:2009, is 100 N / m or more and 800 N / m or less. (ii) The holding strength of the tape, determined in accordance with JIS Z 0237:2009, is 0.3 mm or more and 1.0 mm or less for 15 minutes. (iii) The ball number in an inclined ball tack using tape with an inclined plate angle set at 30° in accordance with JIS Z 0237:2009 is 15 or less.

[0037] Regarding condition (i), if the peel adhesive strength of the tape is 100 N / m or more, the protective film 10a can be easily attached to an article such as clothing. If the peel adhesive strength of the tape is 800 N / m or less, the protective film 10a can be easily peeled off from an article such as clothing.

[0038] Regarding condition (ii), if the holding strength of the tape is 0.3 mm or more after 15 minutes, the protective film 10a is less likely to peel off due to external forces such as friction, and the article to be protected is more likely to be properly protected. Also, if the holding strength of the tape is 1.0 mm or less after 15 minutes, the protective film 10a can be easily peeled off from the article such as clothing after use.

[0039] By satisfying the condition (iii), the adhesive or bonding agent is less sticky, and the protective film 10a can be used comfortably.

[0040] The adhesive and pressure-sensitive adhesive materials are not limited to specific materials. Examples of adhesive and pressure-sensitive adhesive materials include at least one selected from the group consisting of vinyl acetate resin, ethylene-vinyl acetate copolymer, isobutene-maleic anhydride copolymer resin, acrylic copolymer resin, styrene-butadiene rubber copolymer, vinyl acetate resin, acrylic copolymer resin, vinyl chloride resin, chloroprene rubber, nitrile rubber, recycled rubber, SBR, isocyanate-polyol, epoxy resin, silicone resin, modified silicone resin, polyacrylic resin, starch, modified epoxy resin, silylated urethane resin, SBS resin, ethylene-vinyl acetate resin, and cyanoacrylate resin. The adhesive and pressure-sensitive adhesive preferably contain at least one of polyacrylic acid and polyacrylic acid derivatives. In this case, the adhesive and pressure-sensitive adhesive have high safety.

[0041] As shown in FIG. 1 , the protective film 10a has, for example, a first main surface P1 and a second main surface P2. The first main surface P1 is formed of an adhesive or pressure-sensitive adhesive. For example, the protective film 10a has a contact layer 12 formed of an adhesive or pressure-sensitive adhesive. At least a low refractive index material is present on the second main surface P2. For example, the contact layer 12 is pressed against an article to be protected, and the protective film 10a is attached to the article. At this time, the second main surface P2 may be exposed. Because at least a low refractive index material is present on the second main surface P2, the protective film 10a is difficult to see. Note that the protective film 10a may be configured so that the adhesive or pressure-sensitive adhesive is present inside the structure 11.

[0042] The content of the adhesive and the pressure-sensitive adhesive in the protective film 10a is not limited to a specific value. The content is, for example, 0.01% or more and 50% or less by mass. In this case, the protective film 10a can be easily attached to the article to be protected. The content of the adhesive and the pressure-sensitive adhesive may be 0.05% or more by mass. In this case, the protective film 10a can be easily attached to the article to be protected.

[0043] The pressure-sensitive adhesive and adhesive have, for example, a weight-average molecular weight of 10,000 or more and 2,000,000 or less. When the pressure-sensitive adhesive and adhesive have a weight-average molecular weight of 10,000 or more, the viscosity of the pressure-sensitive adhesive and adhesive increases, and a high adhesive or bonding effect is likely to be exhibited. When the pressure-sensitive adhesive and adhesive have a weight-average molecular weight of 2,000,000 or less, the viscosity of the pressure-sensitive adhesive and adhesive is suitable for handling, and an appropriate adhesive or bonding effect is likely to be exhibited.

[0044] The protective film 10a is, for example, 0.01 cm 3 / g In this case, dirt such as sebum is unlikely to permeate the protective film 10a. cm 3 / g In this case, scattering of light by the pores can be suppressed, and the protective film 10a is less visible. The pore volume of the protective film 10a can be determined based on the measurement results of a gas adsorption method using nitrogen, for example. The pore volume of the protective film 10a is preferably 0.002 cm 3 / g This makes it possible to more reliably suppress scattering of light due to pores, and makes the protective film 10a attached to the article to be protected less visible.

[0045] The protective film 10a may be a self-supporting film. In this specification, the term "self-supporting film" refers to a film that can maintain its shape without a support. For example, when a part of the self-supporting film is pinched with fingers or tweezers and the self-supporting film is lifted, the entire self-supporting film can be lifted without a support without damaging the self-supporting film. As shown in FIG. 1, the protective film 10a has, for example, a first region 14f and a second region 14s. The first region 14f is a planar region that is in contact with the first main surface P1 and spaced apart from the second main surface P2 in the thickness direction of the protective film 10a. The second region 14s is a planar region that is located between the first region 14f and the second main surface P2 in the thickness direction of the protective film 10a. For example, in the protective film 10a, the bulk density of the regenerated cellulose in the second region 14s is lower than the bulk density of the regenerated cellulose in the first region 14f. This configuration makes it easier for the second region 14s of the protective film 10a to contain a desired amount of adhesive or pressure-sensitive adhesive. The protective film 10a may have at least one region, such as a third region, whose bulk density is different from that of the first region 14f and the second region 14s. The third region may be disposed, for example, between the first main surface P1 and the first region 14f, between the first region 14f and the second region 14s, or between the second region 14s and the second main surface P2.

[0046] For example, the protective film 10a can be used to provide the protective sheet 50a shown in Fig. 2A. The protective sheet 50a includes, for example, the protective film 10a and a first protective layer 21. The first protective layer 21 is disposed on at least one of the first main surface P1 and the second main surface P2 of the protective film 10a. The first protective layer 21 is removable from the protective film 10a.

[0047] The first protective layer 21 is disposed, for example, on the second main surface P2. The second main surface P2 is, for example, the main surface that is exposed when the protective film 10a is used.

[0048] The first protective layer 21 may be, for example, (i) a sheet, woven fabric, nonwoven fabric, or mesh of a polymeric material such as polyethylene, polypropylene, polyethylene terephthalate, nylon, acrylic resin, polycarbonate, polyvinyl chloride, acrylonitrile butadiene styrene (ABS) resin, polyurethane, synthetic rubber, cellulose, Teflon (registered trademark), aramid, or polyimide; (ii) a metal sheet; or (iii) a glass sheet. The entire or a portion of the surface of the first protective layer 21 may be subjected to a chemical or physical surface treatment. The first protective layer 21 may have a shape identical or different from that of the protective film 10a in a plan view, and a size identical or different from that of the protective film 10a. For example, multiple protective films 10a may be disposed on a single first protective layer 21. The protective film 10a can maintain its shape even without the first protective layer 21. Therefore, even if the first protective layer 21 is removed from the second main surface P2, the protective film 10a can maintain its shape.

[0049] As shown in FIG. 2A , for example, the protective sheet 50a is brought close with the first main surface P1 of the protective film 10a facing a specific portion of the article 5 (e.g., clothing), and the first main surface P1 of the protective film 10a is brought into contact with the specific portion of the article 5. At this time, for example, a mounting agent may be supplied to the specific portion of the article 5 or the protective film 10a. The mounting agent may contain components such as water, oils, alcohol, or an emulsifier. The mounting agent may also contain a predetermined active ingredient. Next, as shown in FIG. 2B , the first protective layer 21 is peeled off from the second main surface P2 of the protective film 10a. At this time, the protective film 10a is in close contact with the article 5, and the protective film 10a remains attached to the article 5. When the first protective layer 21 is completely peeled off, the entire second main surface P2 of the protective film 10a is exposed, as shown in FIG. 2C .

[0050] The protective sheet 50a may be modified as in the protective sheet 50b shown in Figure 3. Unless otherwise specified, the protective sheet 50b has the same configuration as the protective sheet 50a. Components of the protective sheet 50b that are the same as or correspond to components of the protective sheet 50a are given the same reference numerals, and detailed explanations will be omitted. The explanations regarding the protective sheet 50a also apply to the protective sheet 50b, unless technically inconsistent.

[0051] 3, the protective sheet 50b further includes, for example, a second protective layer 22. The second protective layer 22 is disposed on the first main surface P1. The second protective layer 22 can protect the first main surface P1. Furthermore, the second protective layer 22 makes the protective sheet 50b easy to handle.

[0052] The material of the second protective layer 22 may be the same as or different from the material of the first protective layer 21. The second protective layer 22 has a shape that is the same as or different from the shape of the protective film 10a in a planar view, and a size that is the same as or different from the size of the protective film 10a. The second protective layer 22 has a shape that is the same as or different from the shape of the first protective layer 21 in a planar view, and a size that is the same as or different from the size of the first protective layer 21.

[0053] The second protective layer 22 is typically removable from the first main surface P1. When using the protective sheet 50a, for example, the second protective layer 22 is first peeled off from the protective film 10a. This exposes the first main surface P1. Thereafter, the first main surface P1 is brought close to a specific portion of the article 5, and the protective film 10a is attached to the specific portion of the article 5 in the same manner as in using the protective sheet 50a.

[0054] The protective film 10a may be cut before use. For example, as shown in FIG. 4, protective film strips 20 are obtained by cutting the protective film 10a. The strips 20 have a thickness of 100 nm to 2000 nm and a maximum length of 0.1 μm to 100 μm for 80% or more of the volume of the measured range of 0.02 μm to 2800 μm. This maximum length value refers to an aggregate obtained by aggregating multiple strips 20. When 80% or more of the volume of the strips 20 have a maximum length of 0.1 μm or more, the strips 20 easily overlap on the item to be protected, making it difficult for dirt such as sebum to adhere to the item to be protected. When 80% or more of the volume of the strips 20 have a maximum length of 100 μm or less, the strips 20 easily disperse in water or organic solvents such as ethanol and polyhydric alcohols. In addition, since such strips 20 account for 80% or more by volume of the aggregate of strips, there is little discomfort such as roughness when wearing the strips 20. The polyhydric alcohol may be, for example, butanediol, propanediol, glycerol, propylene glycol, polyethylene glycol, diglycerin, pentylene glycol, and dipropylene glycol.

[0055] The thickness of the strips 20 typically corresponds to the thickness of the protective film 10a. The maximum length of the strips 20 typically is the maximum length in a direction perpendicular to the thickness direction of the protective film 10a. The maximum length of the strips 20 is typically equal to or greater than the thickness of the protective film 10a.

[0056] The protective film 10a can be attached to a predetermined item to be protected, thereby protecting the item.

[0057] The protective film 10a can be attached to an article, for example, with the first main surface P1 of the protective film 10a disposed between the article and the second main surface P2.

[0058] The article protected by the protective film 10a is not limited to a specific article. The article protected by the protective film 10a may be, for example, a mirror, a lens, a cloth, a curtain, a sofa, a bed, a partition, an air conditioner, a fan, shoes, a desk, a board, a chair, a door, a mobile phone, a bag, a hat, a display such as a liquid crystal display for a personal computer or a TV, glass, a wall, a floor, a ceiling, a plant, or a living organism such as an animal, including a pet. The protective film 10a can be attached to these articles.

[0059] The article protected by the protective film 10a may be, for example, clothing. The fibers forming the clothing are not limited to a specific fiber. Examples of the fibers forming the clothing include regenerated fibers such as cotton, silk, linen, wool, rayon, polynosic, cupra, and lyocell; semi-synthetic fibers such as promix, triacetate, and acetate; and synthetic fibers such as polyester, nylon, acrylic, and polyurethane. The clothing protected by the protective film 10a may contain at least one fiber selected from these fibers. By attaching the protective film 10a to clothing, the clothing can be protected from foreign substances such as sweat, sebum, dust, PM2.5, and pollen. Additionally, the low refractive index material contained in the protective film 10a makes the protective film 10a less visible when attached to clothing.

[0060] When attaching the protective film 10a to an article, the protective film 10a may be thermocompression bonded to the article. The temperature of the heated surface during thermocompression bonding may be, for example, 120°C or higher. In this case, the anchoring effect of the pressure-sensitive adhesive or adhesive makes the protective film 10a more easily conformable to the article, and it is expected that a high adhesive or bonding effect will be exhibited. This makes it easier to attach the protective film 10a to articles such as clothing. The temperature of the heated surface during thermocompression bonding may be 150°C or higher. In this case, it is easier to attach the protective film 10a to articles such as clothing.

[0061] Water may be used when attaching the protective film 10a to the article. This allows the adhesive or glue to better fit the article, making it easier to attach the protective film 10a to the article. The water may be provided by dripping, spraying, or other methods.

[0062] The small pieces 20 can also be used to protect an article. For example, a dispersion liquid in which the small pieces 20 are dispersed is prepared. This dispersion liquid is applied to an article to form a protective film. This protects the article.

[0063] The method for attaching the dispersion of the flakes 20 to an article is not limited to a specific method. For example, a protective film can be formed by spraying the dispersion of the flakes 20 onto the article. The dispersion medium of the dispersion of the flakes 20 is not limited to a specific dispersion medium, but may be, for example, water, ethanol, or a polyhydric alcohol. The flakes 20 contained in the dispersion attached to the article may be heat-pressed to the article. The temperature of the heating surface in the heat-pressing is, for example, 120°C or higher. If the article to be protected is clothing, a clothing iron or the like can be used to heat-press the flakes 20.

[0064] If the article to be protected is clothing, a clothing iron or the like can be used to thermally press the protective film 10a onto the article. Thermal pressing may be performed using an attachment device 30a shown in FIG. 5. The attachment device 30a includes a storage section 31a, a heating surface 32a, and a supplier 33a. The protective film 10a is stored in the storage section 31a. The heating surface 32a is capable of generating heat at a temperature of 120°C or higher. The supplier 33a supplies the protective film 10a from the storage section 31a onto the heating surface 32a.

[0065] When water is used to attach the protective film 10a to the article, the protective film 10a may be attached to the article using, for example, an attachment device 30b shown in Fig. 6. The attachment device 30b includes a storage section 31b, a supply port 35, and a supplier 33b. The protective film 10a is stored in the storage section 31b. Water is supplied to the article through the supply port 35. The supplier 33b supplies the protective film 10a so that the water comes into contact with the protective film 10a.

[0066] For example, a protective film can be formed from the strips 20 using a mounting device 40 shown in FIG. 7. The mounting device 40 includes a storage section 41, a heating surface 42, and a supply path 43. The storage section 41 stores a dispersion liquid 25. The dispersion liquid 25 has the strips 20 dispersed therein, and the dispersion liquid 25 contains a dispersion medium 22. The heating surface 42 is capable of generating heat at 120°C or higher. The supply path 43 guides the dispersion liquid 25 from the storage section 41 onto the heating surface 42. When the heating surface 42 is heated, the heating surface is pressed against an article, and the dispersion liquid 25 is supplied onto the heating surface 42, thereby thermocompressing the strips 20 to the article.

[0067] The protective film 10a can be modified from various viewpoints. For example, the protective film 10a may be modified to a protective film 10b shown in FIG. 8. The protective film 10b has the same configuration as the protective film 10a except for portions that will be particularly described. The same reference numerals are used to designate components of the protective film 10b that are the same as or correspond to the components of the protective film 10a, and detailed description thereof will be omitted. The description of the protective film 10a also applies to the protective film 10b unless technically inconsistent.

[0068] The protective film 10b includes, for example, a low refractive index layer 13. The low refractive index layer 13 contains a low refractive index material having a refractive index of less than 1.55. The low refractive index layer 13 is formed, for example, on a major surface of the structure 11 that is distal to the contact layer 12. The protective film 10b makes it difficult to see the light scattered from the surface of the low refractive index layer 13 and the surface of the structure 11, canceling out each other.

[0069] An example of a method for producing the protective film 10a or 10b will be described. First, cellulose is dissolved in a solvent to prepare a cellulose solution. To obtain regenerated cellulose with a weight-average molecular weight of 100,000 or more, cellulose with a weight-average molecular weight of at least 100,000 is used. This makes it easy to prepare a protective film with a thickness of 100 nm or more and 2000 nm or less. By increasing the weight-average molecular weight of the cellulose used in preparing the cellulose solution, more hydroxyl groups are contained in one molecular chain. This makes it possible to form many intermolecular hydrogen bonds, allowing for the stable production of a thin protective film. The cellulose used in preparing the cellulose solution is not particularly limited as long as it has the desired weight-average molecular weight.

[0070] The cellulose used to prepare the solution can be either natural cellulose or regenerated cellulose. The cellulose used to prepare the cellulose solution can be, for example, cellulose derived from plants such as pulp and cotton, or cellulose produced by organisms such as bacteria. The impurity concentration in the cellulose raw material is, for example, 20% by weight or less. If the weight-average molecular weight of the cellulose is too high, the viscosity of the solution increases, making it difficult to process. Therefore, the weight-average molecular weight of the regenerated cellulose in the final protective film 10a or 10b is preferably 2,000,000 or less, more preferably 1,000,000 or less, even more preferably 500,000 or less, and most preferably 300,000 or less. A weight-average molecular weight of 2,000,000 or less makes processing possible, a weight-average molecular weight of 1,000,000 or less makes processing easier, a weight-average molecular weight of 500,000 or less makes processing even easier, and a weight-average molecular weight of 300,000 or less makes it possible to obtain a more stable sheet with less thickness variation. The solvent is, for example, a solvent (first solvent) containing at least an ionic liquid. By using the first solvent, cellulose can be dissolved in a relatively short time. An ionic liquid is a salt composed of an anion and a cation and can be in a liquid state at temperatures of 150°C or less. The ionic liquid contained in the first solvent is, for example, an ionic liquid containing an amino acid or an alkyl phosphate ester. By containing such an ionic liquid in the first solvent, cellulose can be dissolved while suppressing a decrease in the molecular weight of cellulose. Cellulose may be dissolved using an ionic liquid pre-diluted with a solvent that does not precipitate cellulose. For example, a mixture of an aprotic polar solvent and an ionic liquid may be used as the first solvent. Aprotic polar solvents are less likely to form hydrogen bonds and less likely to precipitate cellulose.

[0071] The ionic liquid contained in the first solvent is, for example, an ionic liquid represented by the following formula (II). In the ionic liquid represented by formula (II), the anion is an amino acid. As shown in formula (II), in this ionic liquid, the anion contains a terminal carboxyl group and a terminal amino group. The cation of the ionic liquid represented by formula (II) may be a quaternary ammonium cation.

[0072] [ka]

[0073] In formula (II), R1 to R6 independently represent a hydrogen atom or a substituent. The substituent may be an alkyl group, a hydroxyalkyl group, or a phenyl group. The substituent may include a branch in the carbon chain. The substituent may include a functional group such as an amino group, a hydroxyl group, or a carboxyl group. n is, for example, 4 or 5.

[0074] The ionic liquid contained in the first solvent may be an ionic liquid represented by the following formula (III): In formula (III), R1, R2, R3, and R4 independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0075] [ka]

[0076] A second solvent may be further added in the process of preparing the cellulose solution. For example, the second solvent may be further added to a mixture of cellulose having a predetermined weight-average molecular weight and the first solvent. The second solvent is, for example, a solvent that does not precipitate cellulose. The second solvent may be an aprotic polar solvent. The cellulose concentration in the cellulose solution is typically 0.2 wt% or more and 15 wt% or less. When the cellulose concentration in the cellulose solution is 0.2 wt% or more, a protective film having the strength necessary to maintain its shape while reducing its thickness can be obtained. Furthermore, when the cellulose concentration in the cellulose solution is 15 wt% or less, cellulose precipitation in the cellulose solution can be suppressed. The cellulose concentration in the cellulose solution may be 1 wt% or more and 10 wt% or less. When the cellulose concentration in the cellulose solution is 1 wt% or more, a protective film having higher strength can be obtained. When the cellulose concentration in the cellulose solution is 10 wt% or less, a stable cellulose solution with reduced cellulose precipitation can be prepared. Furthermore, a low refractive index material may be dissolved or dispersed in the cellulose solution. Alternatively, the low refractive index material may be first dissolved or dispersed in the first or second solvent, and then mixed with the cellulose solution to dissolve or disperse the low refractive index material. Alternatively, the low refractive index material may be mixed with the cellulose solution in a state heated to or above the glass transition temperature without using a solvent, and then used in the subsequent process.

[0077] Next, the cellulose solution is applied to the surface of the substrate to form a liquid film on the surface of the substrate. The contact angle of the substrate surface with water is, for example, 95° or less. In this case, the cellulose solution has appropriate wettability with respect to the substrate, and a liquid film that spreads along the surface of the substrate can be stably formed. In this case, the cellulose solution has appropriate wettability with respect to the substrate, and a liquid film that spreads along the surface of the substrate can be stably formed. The material of the substrate is not particularly limited. The substrate typically has a non-porous structure with a smooth surface. In this case, the cellulose solution can be prevented from penetrating into the interior of the substrate, and the protective film can be easily separated from the substrate in a subsequent process.

[0078] The substrate may be subjected to chemical or physical surface modification. For example, a polymer material substrate that has been subjected to a surface modification treatment such as ultraviolet (UV) irradiation or corona treatment may be used. The method of surface modification is not particularly limited. For example, application of a surface modifier, surface modification, plasma treatment, sputtering, etching, or blasting may be applied.

[0079] Methods for forming a liquid film of a cellulose solution on a substrate include, for example, gap coating, which forms a predetermined gap between the surface of the substrate and the applicator, slot die coating, spin coating, coating using a bar coater (metering rod coating), and gravure coating. In this case, the thickness of the protective film can be adjusted by adjusting the thickness of the liquid film and the concentration of the cellulose solution. The thickness of the liquid film can be adjusted by the gap thickness or the size and coating speed of the slot die opening, the rotation speed of the spin coater, or the depth and coating speed of the grooves of the bar coater or gravure coater. The method for forming a liquid film of the cellulose solution on a substrate may also be casting, screen printing using a squeegee, spray coating, or electrostatic spraying.

[0080] When forming a liquid film of the cellulose solution on the substrate, at least one of the cellulose solution and the substrate may be heated. The cellulose solution may be heated, for example, within a temperature range (e.g., 40°C or higher and 100°C or lower) at which the cellulose solution can be kept stable. The liquid film of the cellulose solution formed on the substrate may be heated. The liquid film may be heated, for example, at a temperature (e.g., 50°C or higher and 200°C or lower) lower than the decomposition temperature of the ionic liquid contained in the first solvent. By heating the liquid film at such a temperature, solvents other than the ionic liquid (e.g., the second solvent) can be adequately removed, and the strength of the protective film is likely to be increased. The liquid film may be heated in a reduced pressure environment. In this case, solvents other than the ionic liquid can be adequately removed in a shorter time at a temperature lower than the boiling point of the solvent.

[0081] After forming a liquid film of the cellulose solution on the substrate, the liquid film may be gelled. For example, the liquid film can be gelled by exposing it to the vapor of a liquid that is soluble in the ionic liquid but does not dissolve cellulose, thereby obtaining a polymer gel sheet. For example, if the liquid film is left in an environment with a relative humidity of 30% RH or higher and 100% RH or lower, the ionic liquid in the liquid film comes into contact with water, reducing the solubility of cellulose in the liquid film. This causes some of the cellulose molecules to precipitate, forming a three-dimensional structure. As a result, the liquid film gels. The presence or absence of a gelation point can be determined by whether the gelled film can be lifted. The liquid film may be heated before, after, or both before and after gelation.

[0082] Next, the substrate and polymer gel sheet are immersed in a rinse liquid, which is a liquid that does not dissolve cellulose. In this process, the ionic liquid is removed from the polymer gel sheet. This process can be understood as a process of washing the polymer gel sheet. In addition to the ionic liquid, some of the components contained in the cellulose solution other than cellulose and the ionic liquid (e.g., the second solvent) may also be removed in this process. The rinse liquid is typically a liquid that can dissolve the ionic liquid. Examples of such liquids include water, methanol, ethanol, propanol, butanol, octanol, toluene, xylene, acetone, acetonitrile, dimethylacetamide, dimethylformamide, and dimethyl sulfoxide.

[0083] The polymer gel sheet may then be immersed in a solution or dispersion of a low refractive index material or a solution or dispersion of a component of a pressure-sensitive adhesive or adhesive. The solvent for the solution or the dispersion medium for the dispersion may be at least one selected from the group consisting of water, methanol, ethanol, propanol, butanediol, propanediol, glycerol, propylene glycol, polyethylene glycol, diglycerin, pentylene glycol, dipropylene glycol butanol, acetone, glycerin, propanediol, 1,3-butanediol, 1,4-butanediol, diglycerin, polyethylene glycol, dimethicone, tetrahydrofuran (THF), toluene, methyl acetate, ethyl acetate, tetrachloroethylene, petroleum ether, acetonitrile, diethyl ether, methylene chloride, chloroform, N,N-dimethylformamide, acetic acid, formic acid, hexane, and decane. Alternatively, the polymer gel sheet may be immersed in a solution or dispersion of a low refractive index material and then in a solution or dispersion of a pressure-sensitive adhesive or adhesive component, or vice versa. Alternatively, the polymer gel sheet may be immersed only in a solution or dispersion of a low refractive index material, or only in a solution or dispersion of a pressure-sensitive adhesive or adhesive component. Instead of immersing the polymer gel sheet in a solution or dispersion of a low refractive index material, the low refractive index material may be attached to the polymer gel sheet by spraying, vapor deposition, or coating.

[0084] Unnecessary components such as the solvent are removed from the polymer gel sheet. In other words, the polymer gel sheet is dried. Drying methods such as natural drying, vacuum drying, heat drying, freeze drying, and supercritical drying can be applied to dry the polymer gel sheet. Vacuum heating may also be used to dry the polymer gel sheet. The conditions for drying the polymer gel sheet are not particularly limited. A time and temperature sufficient to remove the second solvent and the rinse liquid are selected as the conditions for drying the polymer gel sheet. By removing the solvent from the polymer gel sheet, a protective film 10a or 10b is obtained.

[0085] When freeze-drying or supercritical drying is used in the process of drying a polymer gel sheet, a protective film with a porous structure and low bulk density is more likely to be obtained than when natural drying, vacuum drying, or heat drying is used. The porous structure allows the protective film 10a or 10b to contain a large amount of adhesive or adhesive. Furthermore, when a liquid such as water is used to attach the protective film 10a or 10b to an article, the liquid easily penetrates into the protective film 10a or 10b, making it easy to attach the protective film 10a or 10b to the article. When freeze-drying is used in the process of drying a polymer gel sheet, for example, a solvent that can be frozen and has a boiling point of approximately 100°C to 200°C is used. For example, freeze-drying can be performed using a solvent such as water, tert-butyl alcohol, acetic acid, 1,1,2,2,3,3,4-heptafluorocyclopentane, or dimethyl sulfoxide.

[0086] In the above method, prior to drying the polymer gel sheet, the polymer gel sheet is immersed in a solution or dispersion of a low refractive index material, or a solution or dispersion of a pressure-sensitive adhesive or adhesive component. Alternatively, a step of attaching the low refractive index material, pressure-sensitive adhesive, or adhesive component may be performed after drying the polymer gel sheet. For example, the polymer sheet obtained by drying the polymer gel sheet may be immersed in a solution or dispersion of a low refractive index material, or a solution or dispersion of a pressure-sensitive adhesive or adhesive component. The immersed polymer gel sheet is then further dried. In this case, the low refractive index material, pressure-sensitive adhesive, or adhesive component may also be attached to the polymer gel sheet by spraying, vapor deposition, or coating. [Example]

[0087] The protective film of the present disclosure will be described in more detail using examples, but the protective film of the present disclosure is not limited to the following examples.

[0088] Example 1 Bleached pulp made from wood with a cellulose purity of 80% or more was prepared. The SP value of this bleached pulp was 31.8 MPa. 1 / 2The weight-average molecular weight of the cellulose contained in the bleached pulp, measured by Gel Permeation Chromatography (GPC)-Multi Angle Light Scattering (MALS) method, was approximately 230,000. This measurement was performed using a Shimadzu LC-20AD liquid delivery unit, a Wyatt Technology Corporation Optilab rEX differential refractometer, and a DAWN HELEOS multi-angle light scattering detector. The column used was a Tosoh TSKgel α-M column, and the solvent was a solution of lithium chloride in dimethylacetamide (lithium chloride concentration: 0.1 M). This measurement was performed at a column temperature of 23°C and a flow rate of 0.8 mL / min.

[0089] A cellulose solution was prepared by dissolving bleached pulp in an ionic liquid (ethylmethylimidazolium diethylphosphate). The ionic liquid had a weight-average molecular weight of 180,000, a refractive index of 1.42, and an SP value of 22.7 MPa. 1 / 2 A PVDF solution, prepared by dissolving polyvinylidene fluoride (PVDF) in dimethyl sulfoxide, was mixed with a cellulose solution to prepare a PVDF-cellulose solution. Next, a gap coating process was applied to the surface of a glass substrate, forming a coating film on the glass substrate. The size of the gap in the gap coating was adjusted to achieve a protective film thickness of 500 nm. The coating film was then dried and washed to remove the ionic liquid, yielding a polymer gel sheet.

[0090] A polymer gel sheet was immersed in ultrapure water to impregnate the polymer gel sheet. The polymer gel sheet was placed on a solvent-permeable nonwoven fabric. An aqueous solution containing 1% polyacrylic ester was prepared and applied to the polymer gel sheet. The refractive index of the polyacrylic ester was 1.44, the weight-average molecular weight of the polyacrylic ester was 200,000, the glass transition temperature of the polyacrylic ester was below 0°C, and the SP value of the polyacrylic ester was 23 MPa.1 / 2 In addition, the tape having an adhesive surface formed from this polyacrylic acid ester had a peel adhesive strength of 300 N / m, as determined in accordance with Method 1 of JIS Z 0237:2009. The holding strength of the polyacrylic acid ester, as determined in accordance with JIS Z 0237:2009, was 0.3 mm after 15 minutes. The ball number in an inclined ball tack test using the tape with an inclined plate set at an angle of 30°, as performed in accordance with JIS Z 0237:2009, was 11. The polymer gel sheet was then dried to obtain a protective film according to Example 1. The concentration of PVDF in the protective film was 5.1 wt %, as shown in Table 1, based on the weight of the dried product obtained by extracting PVDF from the protective film using dimethyl sulfoxide and drying it.

[0091] The adhesive content in the protective film according to Example 1 was determined using a spectrophotometer V-770 (JASCO Corporation) using an adhesive solution obtained by extracting the protective film according to Example 1 with isopropanol. As a result, as shown in Table 1, the adhesive content in the protective film according to Example 1 was 1 wt %. The thickness of the protective film according to Example 1 was measured using a stylus profiling system (manufactured by Bruker Nano Inc., product name: DEKTAK (registered trademark)). As a result, as shown in Table 1, the thickness of the protective film according to Example 1 was approximately 450 nm. The thickness of the protective film according to Example 1 was determined by measuring the thickness of the protective film at multiple locations and averaging the measured values.

[0092] Example 2 A protective film according to Example 2 was obtained in the same manner as in Example 1, except that the concentration of PVDF was changed. The concentration of the adhesive in the protective film according to Example 2 was 1 wt %. The concentration of PVDF in the protective film according to Example 2 was 10.3 wt %. The thickness of the protective film according to Example 2 was approximately 460 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0093] Example 3 A protective film according to Example 3 was obtained in the same manner as in Example 1, except that the concentration of PVDF was changed. The concentration of the adhesive in the protective film according to Example 3 was 1 wt %. The concentration of PVDF in the protective film according to Example 3 was 20.3 wt %. The thickness of the protective film according to Example 3 was approximately 440 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0094] Example 4 A protective film according to Example 4 was obtained in the same manner as in Example 1, except for the following points. The PVDF solution in Example 1 was first applied to a glass substrate to form a coating film, and the coating film was dried to remove dimethyl sulfoxide. Thereafter, the cellulose solution in Example 1 was applied to the dried portion of the coating film, and the coating film was dried to obtain a polymer gel sheet. The concentration of the adhesive in the protective film according to Example 4 was 1 wt %. The concentration of PVDF in the protective film according to Example 4 was 10.3 wt %. The thickness of the protective film according to Example 4 was approximately 440 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0095] Example 5 A protective film according to Example 5 was obtained in the same manner as in Example 1, except for the following points. The polymer gel sheet was further immersed in a PVDF solution, and the solvent was dried. In this way, PVDF was incorporated into the protective film. The PVDF solution was prepared in the same manner as that used to prepare the PVDF-cellulose solution. The concentration of the adhesive in the protective film according to Example 5 was 1 wt %. The concentration of PVDF in the protective film according to Example 5 was 10.3 wt %. The thickness of the protective film according to Example 5 was approximately 490 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0096] Example 6 A protective film according to Example 6 was obtained in the same manner as in Example 1, except for the following points. The polymer gel sheet was further immersed in a PVDF solution, and the solvent was dried. In this way, PVDF was incorporated into the protective film. The PVDF solution was prepared in the same manner as that used to prepare the PVDF-cellulose solution. The concentration of the adhesive in the protective film according to Example 6 was 1 wt %. The concentration of PVDF in the protective film according to Example 6 was 10.6 wt %. The thickness of the protective film according to Example 6 was approximately 470 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0097] Example 7 A protective film according to Example 7 was obtained in the same manner as in Example 1, except for the following points. The cellulose solution of Example 1 was applied to a glass substrate to form a coating film, and the coating film was washed to obtain a polymer gel sheet. This polymer gel sheet was immersed in a PVDF solution, and the solvent was dried. This allowed PVDF to be incorporated into the protective film. The PVDF solution was prepared in the same manner as that used to prepare the PVDF-cellulose solution. The polymer gel sheet was dried while being stretched in biaxial directions to obtain a protective film according to Example 7. The concentration of the adhesive in the protective film according to Example 7 was 1 wt %. The concentration of PVDF in the protective film according to Example 7 was 10.6 wt %. The thickness of the protective film according to Example 7 was approximately 470 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0098] Example 8 A protective film according to Example 8 was obtained in the same manner as in Example 1, except that polymethyl methacrylate (PMMA) was used instead of PVDF and its concentration was adjusted as shown in Table 1. The weight-average molecular weight of polymethyl methacrylate was 150,000, the refractive index of polymethyl methacrylate was 1.49, and the SP value of polymethyl methacrylate was 23.8 MPa. 1 / 2 The concentration of the adhesive in the protective film of Example 8 was 1 wt %. The concentration of polymethyl methacrylate in the protective film of Example 8 was 10.2 wt %. The thickness of the protective film of Example 8 was approximately 440 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0099] Example 9 A protective film according to Example 9 was obtained in the same manner as in Example 1, except that polybutyl methacrylate (PBMA) was used instead of PVDF and its concentration was adjusted as shown in Table 1. The weight-average molecular weight of the polybutyl methacrylate was 200,000, the refractive index of the polybutyl methacrylate was 1.47, and the SP value of the polybutyl methacrylate was 23.2 MPa. 1 / 2 The concentration of the adhesive in the protective film of Example 9 was 1 wt %. The concentration of polymethyl methacrylate in the protective film of Example 9 was 10.4 wt %. The thickness of the protective film of Example 9 was approximately 490 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0100] Example 10 A protective film according to Example 10 was obtained in the same manner as in Example 2, except that a different polyacrylic ester was used instead of the polyacrylic ester used in Example 1. The SP value of the polyacrylic ester used to obtain the protective film according to Example 10 was 15 MPa. 1 / 2 In addition, the peel adhesive strength of this polyacrylic ester, determined according to Method 1 of JIS Z 0237:2009, was 290 N / m. The holding strength of the polyacrylic ester, determined according to JIS Z 0237:2009, was 0.4 mm after 15 minutes. The ball number in an inclined ball tack test using the polyacrylic ester with the inclination angle of the inclined plate set at 30°, performed according to JIS Z 0237:2009, was 11. The adhesive concentration in the protective film of Example 10 was 1 wt %. The PVDF concentration in the protective film of Example 10 was 10.3 wt %. The thickness of the protective film of Example 10 was approximately 460 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0101] Example 11 A protective film according to Example 11 was obtained in the same manner as in Example 2, except that a different polyacrylic ester was used instead of the polyacrylic ester used in Example 1. The SP value of the polyacrylic ester used to obtain the protective film according to Example 11 was 25 MPa. 1 / 2 The adhesive strength of this polyacrylate ester was 330 N / m, as determined in accordance with Method 1 of JIS Z 0237:2009. The holding strength of the polyacrylate ester was 0.3 mm after 15 minutes, as determined in accordance with JIS Z 0237:2009. The ball number in an inclined ball tack test using the polyacrylate ester, performed in accordance with JIS Z 0237:2009 with the inclination angle of the inclined plate set at 30°, was 14. The adhesive concentration in the protective film of Example 11 was 1 wt %. The PVDF concentration in the protective film of Example 11 was 10.3 wt %. The thickness of the protective film of Example 11 was approximately 460 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0102] Example 12 A protective film according to Example 12 was obtained in the same manner as in Example 2, except that a different polyacrylic ester was used instead of the polyacrylic ester used in Example 1. The SP value of the polyacrylic ester used to obtain the protective film according to Example 12 was 8 MPa. 1 / 2 The peel adhesive strength of this polyacrylic ester, determined according to Method 1 of JIS Z 0237:2009, was 260 N / m. The holding strength of the polyacrylic ester, determined according to JIS Z 0237:2009, was 0.3 mm after 15 minutes. The ball number in an inclined ball tack test using the polyacrylic ester with the inclined plate set at an angle of 30°, performed according to JIS Z 0237:2009, was 10. The adhesive concentration in the protective film of Example 12 was 1 wt %. The PVDF concentration in the protective film of Example 12 was 10.3 wt %. The thickness of the protective film of Example 12 was approximately 460 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0103] Example 13 A protective film according to Example 13 was obtained in the same manner as in Example 2, except that a different polyacrylic ester was used instead of the polyacrylic ester used in Example 1. The SP value of the polyacrylic ester used to obtain the protective film according to Example 13 was 30 MPa. 1 / 2 The adhesive strength of this polyacrylate ester was 340 N / m, as determined in accordance with Method 1 of JIS Z 0237:2009. The holding strength of the polyacrylate ester was 0.5 mm after 15 minutes, as determined in accordance with JIS Z 0237:2009. The ball number in an inclined ball tack test using the polyacrylate ester, performed in accordance with JIS Z 0237:2009 with the inclination angle of the inclined plate set at 30°, was 15. The adhesive concentration in the protective film of Example 13 was 1 wt %. The PVDF concentration in the protective film of Example 13 was 10.3 wt %. The thickness of the protective film of Example 13 was approximately 450 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0104] Example 14 A protective film according to Example 14 was obtained in the same manner as in Example 2, except that the application of the aqueous polyacrylic acid ester solution was omitted. The PVDF concentration in the protective film according to Example 14 was 10.3 wt %. The thickness of the protective film according to Example 14 was approximately 440 nm. The thickness of the protective film was determined in the same manner as in Example 1.

[0105] Example 15 The protective film according to Example 2 was added to ultrapure water at a concentration of 1 wt %. The protective film in the ultrapure water was shredded using an ultrasonic homogenizer for 30 minutes to obtain a dispersion according to Example 15. Small pieces derived from the protective film were dispersed in the dispersion according to Example 15. When these small pieces were observed under an optical microscope, they had a maximum length of 90 μm. The particle size distribution of the aggregate of these small pieces was measured using a particle size distribution analyzer MT3300EX II (measured particle diameter: 0.02 μm to 2800 μm) manufactured by Microtrackbell Corporation. The measurement results confirmed that small pieces having a particle size of 0.1 μm to 100 μm accounted for 95% of the aggregate by volume.

[0106] (Comparative Example 1) Polylactic acid was dissolved in chloroform at a concentration of 2.4 wt% to obtain a polylactic acid solution. The weight average molecular weight of the polylactic acid was 250,000, and the SP value of the polylactic acid was 11.4 MPa. 1 / 2 The results were as follows: PVDF was added to the polylactic acid solution. This solution was then spin-coated onto a substrate containing polyvinyl alcohol having a weight-average molecular weight of approximately 500, producing a polylactic acid sheet. The solvent, chloroform, was then evaporated. An aqueous solution containing 1% of polyacrylic acid ester, an adhesive having a glass transition temperature of 0°C or lower, was prepared, and the aqueous solution of polyacrylic acid ester was applied onto the polylactic acid sheet and dried. The polylactic acid sheet was then immersed in water to dissolve the polyvinyl alcohol, and the adhering water was dried to produce a polylactic acid film. The polylactic acid film was then immersed in a 20% by mass aqueous glycerin solution, followed by drying, to obtain a film according to Comparative Example 1. The thickness of the film according to Comparative Example 1 was approximately 450 nm.

[0107] (Comparative Example 2) Except for not using PVDF and polyacrylic acid ester, a membrane according to Comparative Example 2 was obtained in the same manner as in Comparative Example 1. The thickness of the membrane according to Comparative Example 2 was about 450 nm.

[0108] (Comparative Example 3) A commercially available polyurethane elastomer film was obtained as the film according to Comparative Example 3. The thickness of this polyurethane elastomer film was 30 μm, and the refractive index was 1.6. This polyurethane elastomer film was subjected to a pressure of 23 MPa 1 / 2 The polyurethane elastomer film contained a pressure-sensitive adhesive, which was a polyacrylic acid ester having an SP value of 1. The content of the polyacrylic acid ester in this polyurethane elastomer film was 1% by weight.

[0109] <Measurement of pore volume> The pore volumes in the protective films of Examples 2, 4, 6, and 7 and the film of Comparative Example 3 were measured by gas adsorption using a BELSORP mini-II (manufactured by Microtrack-Bell Corporation). The results are shown in Table 2. In Table 2, values ​​not measured are indicated by "-". According to Table 2, the film of Comparative Example 3 had an overwhelmingly large pore volume. On the other hand, the pore volume did not change even when PVDF was formed into a layer, and the pore volume of the protective film of Example 7, which was obtained by drying in a biaxially stretched state, was the smallest.

[0110] <Light transmittance measurement> Using a spectrophotometer (product name: V-770, manufactured by JASCO Corporation), the transmittance of light at 520 nm, which is considered to be the wavelength most easily visible to humans, was measured for the protective films of Examples 1 to 14 and the films of Comparative Examples 1 to 3. The results of this measurement are shown in Table 2. Comparing Examples 1 to 14 with Comparative Examples 1 to 3, it was found that the protective films containing regenerated cellulose had high light transmittance, while the protective films of Examples 1 to 14 were difficult to see. Examples 1 to 3 suggest that increasing the concentration of the low refractive index material in the protective film increases the light transmittance. Among the protective films of Examples 2, 4, and 5, the protective film of Example 5 exhibited the highest light transmittance. This is presumably due to two features: the protective film of Example 5 retains the low refractive index material, and the low refractive index material is layered on the surface by immersion in a solution of the low refractive index material. A comparison between Example 2 and Example 6 suggested that mixing a low refractive index material into a cellulose solution to prepare a polymer gel sheet and then adding the low refractive index material after washing the polymer gel sheet tended to increase the light transmittance of the protective film. This is thought to be due to a decrease in the apparent refractive index of cellulose and a decrease in the apparent scattered light intensity due to interference of scattered light from the low refractive index material layer and the cellulose layer. A comparison between Example 6 and Example 7 showed that the protective film of Example 7 had a higher light transmittance. As described above, the protective film of Example 7 had a small pore volume, which is thought to have led to this result by suppressing light scattering in the pores. According to Examples 2, 8, and 9, the protective film of Example 2 had the highest light transmittance. The refractive index of the low refractive index material PVDF in the protective film of Example 2 was the lowest, which is thought to have led to suppressed interference with transmitted light, resulting in this result. According to Examples 2, 10 to 14, it was suggested that the presence or absence of an adhesive did not significantly affect the light transmittance of the protective film.

[0111] <Pseudo-sebum solution permeation test> Following the method described in JIS L 1919:2012, a membrane permeability test of a simulated sebum solution was conducted for the protective films of Examples 1 to 14, the dispersion of Example 15, and the membranes of Comparative Examples 1 to 3. Ultrapure water was poured onto a 100% cotton dress shirt, and 2 cm squares of the protective films of Examples 1 to 14 and the membranes of Comparative Examples 1 to 3 were attached to obtain samples of Examples 1 to 14 and Comparative Examples 1 to 3. Furthermore, 1 g of the dispersion of Example 15 was applied to the dress shirt to obtain a sample of Example 15. A 0.1 mL portion of a simulated sebum solution containing 61.5% olive oil, 38% oleic acid, and 0.5% oil red was dropped onto each sample from a height of 10 cm. After 12 hours, excess simulated sebum solution was absorbed with filter paper, and the membrane or strip was peeled off from the dress shirt. It was confirmed whether the red dye had penetrated into the shirt. The results are shown in Table 2. Table 2 suggests that sebum permeation can be inhibited, except for Comparative Examples 1 and 2. The SP value of polylactic acid was 11.4 MPa. 1 / 2 and the SP value of cellulose (31.8 MPa 1 / 2 ) and it is thought that this result was due to the fact that polylactic acid has the property of being easily permeable to sebum.

[0112] <Water permeation test> A test was carried out in the same manner as in the <Permeation Test of Artificial Sebum Solution>, except that an aqueous solution in which 0.1% food coloring was dissolved in ultrapure water was used instead of the artificial sebum solution. The results are shown in Table 2. According to Table 2, the films according to Comparative Examples 1 to 3 did not permeate water. This result suggests that the protective films according to Examples 1 to 14 or the strips in the dispersion according to Example 15 are easily permeable to sweat and do not easily cause stuffiness.

[0113] <Peelability test> The protective films of Examples 2, 4, 5, 10, 11, 12, 13, and 14 and the film of Comparative Example 1 were evaluated for ease of peeling from a 100% cotton dress shirt and from 65% polyester and 35% cotton dress shirts. First, each film was attached to a dress shirt in the same manner as in the <Sebum-mimetic Solution Permeation Test>. The samples thus obtained were rubbed with a cotton swab, and the number of times until peeling was counted. The results are shown in Table 3. Comparing Comparative Example 1 with Examples 2 and 14, the polylactic acid film was easy to peel from the dress shirt even though it contained an adhesive. The SP value of polylactic acid was 11.4 MPa 1 / 2 The SP value of the adhesive was low at 10 MPa, which is thought to be due to the poor compatibility of polylactic acid with the adhesive. A comparison of Examples 2, 4, and 5 suggests that the addition of the low refractive index material has almost no effect on the ease of peeling. A comparison of Examples 2, 10, 11, 12, 13, and 14 suggests that the SP value of the adhesive was 10 MPa 1 / 2 More than 30MPa 1 / 2 It was suggested that if the temperature was below this, the protective film would be less likely to peel off from the shirt.

[0114] <Test for ease of peeling by thermocompression bonding> For the protective film of Example 2, it was confirmed whether the ease of peeling changed depending on whether or not the protective film was heat-pressed to a 100% cotton dress shirt at 120°C for 30 seconds. The test was conducted in the same manner as the <Ease of Peeling Test>, except for the heat-pressing. The results are shown in Table 4. As shown in Table 4, it was suggested that when heat-pressing was performed, the number of times the protective film had to be rubbed before it peeled off from the shirt increased. This suggests that heat-pressing improves the adhesion or wearability between the protective film and the dress shirt. It is believed that this result was brought about by the anchor effect of heat-pressing, which increased the adhesive effect between the protective film and the dress shirt.

[0115] <Test for peeling of protective film due to washing> The ease with which the protective film attached to clothing peels off due to washing was evaluated. For this evaluation, the protective film of Example 2 was used and heat-pressed to a 100% cotton dress shirt at 120°C for 30 seconds to prepare Sample A. The protective film of Example 2 was attached to a 100% cotton dress shirt without heat-pressing to prepare Sample B. The condition of the shirt after washing was visually inspected to confirm whether or not the protective film had peeled off. The results are shown in Table 5. The film of Example 2 could be peeled off from the shirt regardless of whether or not heat-pressing was performed at 120°C. This demonstrated that the protective film can be easily peeled off from clothing when no longer needed. Because the polyacrylic acid ester used as the adhesive is dispersible in water, it is believed that the protective film can be peeled off from the shirt by washing.

[0116] [Table 1]

[0117] [Table 2]

[0118] [Table 3]

[0119] [Table 4]

[0120] [Table 5] [Explanation of symbols]

[0121] 10a, 10b Protective film 11. Structures containing regenerated cellulose 14f First part 14s second part 20 Protective film strip 21 First protective layer 22 First protective layer 25 Dispersion 30a Mounting device 31a Storage section 32a Heating surface 33a feeder 30b Mounting device 31b Storage section 33b Feeder 35 Supply port 40 Mounting device 41 Storage unit 42 Heating surface 43 Supply route P1 First principal surface P2 Second principal surface

Claims

1. Regenerated cellulose, a low refractive index material having a refractive index less than 1.55; A thickness of 100 nm or more and 2000 nm or less, The pore volume measured by gas adsorption method is 0.01 cm 3 / g or less, Protective membrane for clothing.

2. 10. The protective film for clothing of claim 1, wherein the regenerated cellulose has a weight average molecular weight of 100,000 or greater.

3. The low refractive index material has a refractive index of 20 MPa. 1 / 2 25MPa or more 1 / 2 3. The protective film for clothing according to claim 1 or 2, having an SP value of:

4. The protective film for clothing of claim 1 , wherein the low refractive index material comprises a polymer.

5. 5. The protective membrane for clothing of claim 4, wherein the polymer comprises at least one selected from the group consisting of polymethyl methacrylate, polybutyl methacrylate, and polyvinylidene fluoride.

6. The protective film for clothing according to claim 1 , wherein the content of the low refractive index material in the protective film for clothing is 0.1% or more and 50% or less by mass.

7. The protective film for clothing according to claim 1 , wherein the low refractive index material is dispersed in a structure comprising the regenerated cellulose.

8. 8. The protective film for clothing according to any one of claims 1 to 7, further comprising a pressure sensitive adhesive or adhesive.

9. The protective film for clothing according to claim 8 , wherein the pressure sensitive adhesive and the adhesive are soluble or dispersible in water.

10. The protective film for clothing according to claim 8 or 9, wherein the pressure sensitive adhesive and the adhesive have a glass transition temperature of 0°C or higher.

11. The pressure sensitive adhesive and the adhesive are 15 MPa 1 / 2 25MPa or more 1 / 2 11. A protective film for clothing according to any one of claims 8 to 10, having an SP value of:

12. When a tape having an adhesive surface formed by the pressure-sensitive adhesive or the adhesive is produced, The tape pull is determined according to method 1 of Japanese Industrial Standards (JIS) Z 0237:2009. The peeling adhesive strength is 100 N / m or more and 800 N / m or less, The holding strength of the tape determined in accordance with JIS Z 0237:2009 is 0.3 mm or more for 15 minutes 1.0 mm or less, The tape is made in accordance with JIS Z 0237:2009, and the inclination angle of the inclined plate is set to 30°. The ball number in the inclined ball tuck using the 12. A protective film for clothing according to any one of claims 8 to 11.

13. 13. The protective film for clothing according to any one of claims 8 to 12, wherein the pressure sensitive adhesive and the adhesive comprise at least one of polyacrylic acid and polyacrylic acid derivatives.

14. a first main surface formed by the pressure-sensitive adhesive or the adhesive; and a second major surface on which at least the low refractive index material is present.

14. A protective film for clothing according to any one of claims 8 to 13.

15. The protective film for clothing according to any one of claims 8 to 14, wherein the content of the pressure-sensitive adhesive and the adhesive in the protective film for clothing is 0.01% or more and 50% or less by mass.

16. 16. The protective film for clothing according to any one of claims 8 to 15, wherein the pressure sensitive adhesive and the adhesive have a weight average molecular weight of 10,000 or more and 2,000,000 or less.

17. The protective membrane for clothing is a self-supporting membrane, The protective film for clothing includes at least a planar first region located between a first main surface of the protective film for clothing and a second main surface located on the opposite side of the first main surface in a thickness direction of the protective film for clothing, and a planar second region located between the first region and the second main surface in the thickness direction of the protective film for clothing, The bulk density of the regenerated cellulose in the second region is lower than the bulk density of the regenerated cellulose in the first region.

17. A protective film for clothing according to any one of claims 1 to 16.

18. A protective film for clothing according to any one of claims 1 to 16; a removable first protective layer disposed on at least one of the first and second major surfaces of the protective membrane for clothing; Protective sheet.

19. The second main surface is a main surface that is exposed when the protective film for clothing is used, 19. The protective sheet according to claim 18, wherein the first protective layer is disposed on the second major surface.

20. 20. The protective sheet according to claim 19, further comprising a second protective layer disposed on the first major surface.

21. Regenerated cellulose, a low refractive index material having a refractive index less than 1.55; a thickness of 100 nm or more and 2000 nm or less, and a maximum length of 0.1 μm or more and 100 μm or less for 80% or more of the volume; The pore volume measured by gas adsorption method is 0.01 cm 3 / g or less, Protective film strips for clothing.

22. 1. A method for protecting clothing, comprising:

18. A method comprising applying to a garment a protective membrane according to any one of claims 1 to 17.

23. 23. The method of claim 22, comprising applying the protective membrane for a garment as described in claim 17 to the garment with the first major surface of the protective membrane positioned between the garment and the second major surface.

24. 24. The method of claim 22 or 23, wherein the garment protective film is attached to the garment by heat pressing the garment protective film to the garment at a temperature of 120°C or higher.

25. 25. The method of any one of claims 22 to 24, wherein the garment protective membrane is applied to the garment using water.

26. 1. A method for protecting clothing, comprising:

22. A method for forming a protective film for clothing by applying a dispersion in which the strips for a protective film for clothing according to claim 21 are dispersed to the clothing. method.

27. a storage section for storing the protective film for clothing according to any one of claims 1 to 17; A heat generating surface capable of generating heat at a temperature of 120°C or higher; A supplier supplies the clothing protective film from the storage section onto the heating surface, Mounting device.

28. a storage section for storing the protective film for clothing according to any one of claims 1 to 17; a supply port for supplying water; a dispenser for dispensing the garment protective membrane into contact with the water; Mounting device.

29. a storage section for storing a dispersion in which the strips for a protective film for clothing according to claim 21 are dispersed; A heat generating surface capable of generating heat at a temperature of 120°C or higher; a supply path that guides the dispersion liquid from the storage section onto the heat generating surface, Mounting device.

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