WO2023177280A1

WO2023177280A1 - A pressure-sensitive adhesive sheet

Info

Publication number: WO2023177280A1
Application number: PCT/MY2023/050016
Authority: WO
Inventors: Won Ching CHUAH; George Budiyanto LEE; Intan Nadia MOHD AMIR; Yee Yun NEO
Original assignee: Nitto Denko Corporation; Nitto Denko Materials (Malaysia) Sdn Bhd
Priority date: 2022-03-15
Filing date: 2023-03-13
Publication date: 2023-09-21

Abstract

A pressure-sensitive adhesive sheet for providing support to at least one edge of a flexible clothing. The pressure-sensitive adhesive sheet comprises a pressure-sensitive adhesive film having a first adhesive surface and a second adhesive surface, and a flexible sheet adhered to the first adhesive surface, wherein the second adhesive surface of the pressure-sensitive adhesive sheet is removably adhered to an inner surface of the at least one edge of the flexible clothing and the pressure-sensitive adhesive sheet is configured to bend according to a desired shape along an interior contour of the flexible clothing such that the at least one edge of the flexible clothing is prevented from collapsing or deformation when the at least one edge of the flexible clothing is not in contact or supported by a user's body.

Description

A PRESSURE-SENSITIVE ADHESIVE SHEET

FIELD OF INVENTION

The invention relates to the field of adhesives. Particularly, the invention relates to a pressure-sensitive adhesive sheet suitable for use in clothing. More particularly, the invention relates to a pressure-sensitive adhesive sheet for providing support to edges of a flexible clothing.

BACKGROUND OF THE INVENTION

Head covering or headscarf has been around for a long time. It is an example of hair ornament that people wear on their head for a variety of purposes. Head covering can be used to protect the head and hair from the sun, cold, wind, rain and dirt. People also wear head coverings for decorative purposes and various headscarf wearing styles have been introduced over the years. Besides, head coverings are essential clothing item for people of certain ethnics or religion who need to cover their head on a regular basis.

Head covering is commonly made of soft fabric material that have low or no inherent strength to withstand bending. Hence, head covering is prone to bend, deform or collapse at the part where it is not supported by the user’s head, thereby affecting the aesthetic appeal of the head covering. Accordingly, for people who prefer to wear the head covering with the edge being partially protruding from or unsupported by the head, a supporting means is often required for preventing the protruding or unsupported edge of the head covering from bending, deformation or collapsing.

There are various technologies in relation to supporting means for flexible headwear. US1493194 had disclosed a shape retainer for men’s hat. The shape retainer is in the form of a sheet or a plate and is designed to be inserted in the inside front part of the hat between the leather or cloth band and the body of the hat. Nevertheless, the shape retainer is not affixed to the band or the body of the hat and it may be shifted laterally inside the hat. Adjustment of the position of the shape retainer is required when the hat is asymmetrical. Besides, such shape retainer is not suitable for use in head covering that has no space for the insertion of the shape retainer.

Hence, there exists a need for a tool that can be affixed to a soft head covering in order to provide support to the edges of the head covering such that its edges do not bend, collapse or deform when the edges protrude from the user’s head and thus become unsupported by the user’s head. Such tool is provided in the present invention. Furthermore, a head covering comprising such tool is provided in the present invention.

SUMMARY OF INVENTION

The primary object of the invention is to provide a flexible sheet for providing support to and determining the shape of the edges of a soft head covering that are not supported by a user’s head. The flexible sheet is configured to bend according to a desired shape along the interior contour of the head covering in order to retain the shape of the head covering. Particularly, the flexible sheet has adequate tensile strength and elongation ratio such that it does not break easily when it is being bent to conform to the interior contour of the head covering.

Another object of the invention is to provide a flexible pressure-sensitive adhesive sheet for providing support to and determining the shape of the edges of a soft head covering that are not supported by a user’s head. Particularly, the flexible sheet comprises a pressure-sensitive adhesive surface that allows it to be removably adhered to the edge of the head covering.

Further another object of the invention is to provide a reusable flexible pressuresensitive adhesive sheet for providing support to and determining the shape of the edges of a soft head covering that are not supported by a user’s head. Particularly, the pressuresensitive adhesive surface of the pressure-sensitive adhesive sheet possesses adequate adhesive strength that allows it to repeatedly bind and unbind from the head covering.

Still another object of the invention is to provide a flexible pressure-sensitive adhesive sheet for providing support to and determining the shape of the edges of a soft head covering that are not supported by a user’s head, in which the flexible sheet is gentle on fabric. Particularly, the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet possesses adequate adhesive strength that allows it to bind the head covering and removed therefrom without damaging the surface of the head covering.

At least one of the preceding objects is met, in whole or in part, by the present invention, in which the embodiment of the present invention describes a pressure-sensitive adhesive sheet for providing support to at least one edge of a flexible clothing, the pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive film having a first adhesive surface and a second adhesive surface; and a flexible sheet adhered to the first adhesive surface, wherein the second adhesive surface of the pressure-sensitive adhesive sheet is removably adhered to an inner surface of the at least one edge of the flexible clothing and the pressure-sensitive adhesive sheet is configured to bend according to a desired shape along an interior contour of the flexible clothing such that the at least one edge of the flexible clothing is prevented from collapsing or deformation when the at least one edge of the flexible clothing is not in contact or supported by a user’s body.

In one embodiment, the inner surface of the edge is an underside of an awning of the flexible clothing.

In one embodiment, the second adhesive surface has an adhesive strength of 0.05 N/10 mm to 10.00 N/10 mm. In one embodiment, the first adhesive surface has an anchoring strength to the flexible sheet of 0.05 N/10 mm to 10.00 N/10 mm.

In one embodiment, the flexible sheet is made of any one or any combination of a plastic material, a non-plastic material and a biomaterial.

In one embodiment, the pressure-sensitive adhesive sheet has a thickness of 23 pm to 450 pm.

In one embodiment, the pressure-sensitive adhesive sheet has a tensile strength of 0.05 MPa to 300.00 MPa.

In one embodiment, the pressure-sensitive adhesive sheet has an elongation ratio of 1% to 400%.

In one embodiment, the flexible clothing is made of a material selected from a natural material, a synthetic material or a combination thereof. The material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.

The present invention also describes a flexible clothing having at least one edge, the flexible clothing comprising at least one pressure-sensitive adhesive sheet having a pressure-sensitive adhesive film having a first adhesive surface and a second adhesive surface; and a flexible sheet adhered to the first adhesive surface, wherein the second adhesive surface of the pressure-sensitive adhesive sheet is removably adhered to an inner surface of the at least one edge of the flexible clothing and the pressure-sensitive adhesive sheet is configured to bend according to a desired shape along an interior contour of the flexible clothing such that the at least one edge of the flexible clothing is prevented from collapsing or deformation when the at least one edge of the flexible clothing is not in contact or supported by a user’s body. In one embodiment, the flexible clothing is a flexible head covering made of a material selected from a natural material, a synthetic material or a combination thereof. The material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawing the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

Figure 1 is a schematic sectional view of a pressure-sensitive adhesive sheet according to a preferred embodiment of the invention.

Figure 2 is a schematic sectional view of a pressure-sensitive adhesive sheet according to the preferred embodiment of the invention being adhered to a flexible clothing.

Figure 3 illustrates the steps to apply a pressure-sensitive adhesive sheet according to the preferred embodiment of the invention on a head covering.

Figure 4 illustrates (a) the head covering before the application of the pressuresensitive adhesive sheet according to the preferred embodiment of the invention, and (b) the head covering after the application of the pressuresensitive adhesive sheet according to the preferred embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiment described herein is not intended as limitations on the scope of the invention.

The term “backing” refers to the solid material to which the pressure-sensitive adhesive composition of the present invention is applied and dried in uncured condition, and which may become a part of a composite structure when the pressure-sensitive adhesive composition is cured. The term “backing” as used herein can be used interchangeably with the terms “base material” and “carrier” unless otherwise mentioned.

The terms “adherend” and “substrate” as used herein refer to the surface to which a pressure-sensitive adhesive layer of the pressure-sensitive adhesive film of the present invention adheres.

The terms “primer layer” and “anchor layer” as used herein can be used interchangeably unless otherwise mentioned.

The term “adhesive strength” as used herein refers to the adhesive strength of a pressure-sensitive adhesive layer with respect to a surface (i.e. stainless steel and fabric such as cotton, chiffon, satin and silk) after aging for up to 2 hours at room temperature and under atmospheric pressure.

The unit “N/20 mm” for adhesive strength as used herein refers to force per pressuresensitive adhesive tape of 20 mm in width.

The term "weight" as used herein may be read as "mass", which is generally used as an SI unit expressing weight. The term "(meth)acrylic" as used herein refers to "acrylic and/or methacrylic", and the term "(meth)acrylate" as used herein refers to "acrylate and/or methacrylate".

The invention relates to a pressure-sensitive adhesive sheet (100) for providing support to at least one edge (201) of a flexible clothing (200) such that the at least one edge (210) of the flexible clothing (200) is prevented from collapsing or deformation when the at least one edge (210) of the flexible clothing (200) is not in contact or supported by a user’s body. The term “edge” as used herein includes the periphery and the area in the vicinity of the periphery. Preferably, the flexible clothing (200) is made of a fabric material selected from a natural material, a synthetic material or a combination thereof. Examples of fabric material suitable for use as flexible clothing (200) include, but not limited to, cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey, velvet, sateen, gingham, chenille fabric, organza, denim, fleece, tartan, taffeta, damask, tweed, velour, terrycloth, gauze, organdie, corduroy, brocade, felt, challis, flannel, and the like. More preferably, the fabric material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.

According to a preferred embodiment, the pressure-sensitive adhesive sheet (100) is applied onto an underside of the flexible clothing (200) to form a desired shape for the clothing (200). The edge (210) can be an awning of a head covering, collar, yoke, and cuffs. In an example of a head covering such as a hijab, the pressure-sensitive adhesive sheet (100) is adhered to the underside of the awning and bent according to a desired shape to form and retain the shape of the awning.

In the preferred embodiment of the invention, the pressure-sensitive adhesive sheet (100) is a laminate of a pressure-sensitive adhesive film (110) and a flexible sheet (120). Particularly, the pressure-sensitive adhesive film (110) is a double-sided pressuresensitive adhesive film having a first and second pressure-sensitive adhesive layers (111, 112) formed by coating a pressure-sensitive adhesive composition on both surfaces (113a, 113b) of a backing material (113). The first pressure-sensitive adhesive layer (111) has an exposed first adhesive surface (Illa) opposite to the backing material (113) while the second pressure-sensitive adhesive layer (112) has an exposed second adhesive surface (112a) opposite to the backing material (113). The flexible sheet (120) is adhered to the exposed first adhesive surface (Illa) of the first pressure-sensitive adhesive layer (111).

Figure 1 is a schematic sectional view of a pressure-sensitive adhesive sheet (100) according to the preferred embodiment of the invention. In Figure 1, the pressuresensitive adhesive sheet (100) includes a backing material (113), a first pressuresensitive adhesive layer (111), a second pressure-sensitive adhesive layer (112) and a flexible sheet (120), in which the first pressure-sensitive adhesive layer (111) is coated on one surface (113a) of the backing material (113) and forms a first adhesive surface (Illa), the second pressure-sensitive adhesive layer (112) is coated on the other surface (113b) of the backing material (113) and forms a second adhesive surface (112b), and the flexible sheet (120) is adhered to the first adhesive surface (Illa). Any other suitable layer, such as a primer layer, may be formed between the backing material (113) and the first pressure-sensitive adhesive layer (111) and/or between the backing layer (113) and the second pressure-sensitive adhesive layer (112) within such a range as not to impair the effects of the present invention.

In the pressure-sensitive adhesive film (110) of the present invention, the backing material (113) may be formed of one or more layers. Any suitable material may be employed as the backing material (113) as long as it does not impair the effects of the present invention. Examples of material suitable for use as a backing material (113) in the present invention include, but not limited to, fabrics, paper material, foam sheets, metal foil, rubber sheets, plastic film, and a composite thereof. Preferably, fabric and plastic film are employed as the backing material (113) in the pressure-sensitive adhesive sheet (100) disclosed herein. More preferably, the pressure-sensitive adhesive sheet (100) includes non-woven fabric or polyester film as the backing material (113). The surface(s) (113a, 113b) of the backing material (113) may be subjected to any surface treatment to improve the anchoring of the pressure-sensitive adhesive layers (111, 112) to the backing material (113) provided that the surface treatment does not impair the effects of the present invention. Examples of suitable surface treatment include, but not limited to, corona discharge treatment, plasma treatment, UV ray irradiation, acid treatment, alkaline treatment and primer coating. The thickness of the backing material (113) is not particularly limited. Preferably, backing material (113) within thickness in the range of 23 pm to 350 pm is used to ensure adequate tensile strength and/or elongation at break.

Pursuant to the preceding description, the pressure-sensitive adhesive sheet (100) of the present invention may comprise at least one release liner (114) affixed to the exposed second adhesive surface (112a) of the second pressure-sensitive adhesive layer (112) that is opposite to the backing material (113). Any conventional release paper or the like can be used without any particular limitations. A release liner formed by subjecting a liner substrate to a surface treatment with a release agent can be used. The liner substrate includes, but not limited to, resin film, paper, fabric, rubber sheet, foam sheet, metal foil and the like. The release agent used in the surface treatment includes, but not limited to, a silicone-based, a fluorine-based, a molybdenum disulfide-based, a long- chain alkyl-based release agent and the like. Besides, a release liner formed of a poorly- adhesive material such as a fluorine-based polymer (e.g. polytetrafluoroethylene, etc.), a polyolefin-based resin (e.g. polyethylene, polypropylene, etc.) or the like can also be used in the double-sided pressure-sensitive adhesive tape of the present invention.

As set forth in the preceding description, a first pressure-sensitive adhesive layer (111) is coated on a surface (113a) of the backing material (113) and a second pressuresensitive adhesive layer (112) is coated on another surface (113b) of the backing material (113). The surfaces (113a, 113b) of the backing material (113) may be coated entirely or partially with the pressure-sensitive adhesive layers (111, 112). For example, some or all edges of the backing material (113) are not coated with the pressuresensitive adhesive layers (111, 112). The thickness of each pressure-sensitive adhesive layer is not particularly limited. Preferably, the thickness of the pressure-sensitive adhesive layers (111, 112) is about 10 pm to 150 pm to ensure adequate adhesive strength to the substrate (i.e. clothing) and adequate anchoring strength to the flexible sheet. More preferably, the thickness of the pressure-sensitive adhesive layers (111, 112) is about 30 pm to 125 pm.

A primer layer maybe sandwiched between the backing material (113) and the first pressure-sensitive adhesive layer (111) and/or between the backing material (113) and the second pressure-sensitive adhesive layer (112) to strengthen the bonds between the backing material (113) and the pressure-sensitive adhesive layers (111, 112), thereby improving the anchoring strength of the pressure-sensitive adhesive layers (111, 112) as well as the cohesion of the pressure-sensitive adhesive composition. Preferably, a urethane-based primer layer.

Preferably, the first pressure-sensitive adhesive layer (111) and the second pressuresensitive adhesive layer (112) have a pressure-sensitive adhesive strength of 0.05 N/10 mm to 10.00 N/10 mm. More preferably, the first pressure-sensitive adhesive layer (111) and the second pressure-sensitive adhesive layer (112) have a pressure-sensitive adhesive strength of 0.10 N/20 mm to 5.00 N/20 mm. When the pressure-sensitive adhesive strength of the first and second pressure-sensitive adhesive layers (111, 112) falls within the specified range, the pressure-sensitive adhesive sheet (100) would have adequate adhesive strength to the substrate (i.e. clothing) that allows it to repeatedly bind and unbind from the clothing (200) without damaging the surface of the clothing (200). When the pressure-sensitive adhesive strength of the first and second pressuresensitive adhesive layers (111, 112) falls within the specified range, the pressuresensitive adhesive sheet (100) would have adequate anchoring strength to the flexible sheet. Preferably, the first adhesive surface (Illa) has an anchoring strength to the flexible sheet (120) of 0.05 N/10 mm to 10.00 N/10 mm. Particularly, the laminate of the pressure-sensitive adhesive film (110) and the flexible sheet (120) remains in integrated manner when the pressure-sensitive adhesive sheet (100) is re-peeled from the clothing (200) after it is adhered to the clothing (200).

In the preferred embodiment of the invention, the first pressure-sensitive adhesive layer (111) and the second pressure-sensitive adhesive layer (112) are formed of a water- dispersed pressure-sensitive adhesive composition comprising a base polymer. Alternatively, the pressure-sensitive adhesive composition can be a solvent-based pressure-sensitive adhesive composition, hot-melt pressure-sensitive adhesive composition, rubber-based pressure-sensitive adhesive composition or an active energy ray-curable PSA composition which is sensitive to irradiation with active energy rays such as UV rays and electron rays. The base polymer may constitute about 45% to 100% by weight of the total pressure-sensitive adhesive composition. Any suitable polymer may be employed within such a range as not to impair the effects of the present invention. The base polymer may be an acrylic polymer, an olefin-based polymer, a styrene-based polymer, a urethane-based polymer, or a silicone-based polymer. Preferably, the base polymer is an acrylic polymer.

Preferably, the water-dispersed pressure-sensitive adhesive composition further comprises a tackifier resin. The tackifier resin content is 5 parts by weight or greater and 30 parts by weight or less to 100 parts by weight of the acrylic polymer. Examples of the tackifier resin include petroleum-based tackifier resins, terpene-based tackifier resins, phenolic tackifier resins, and ketone-based tackifier resins, including rosinbased tackifier resins and rosin derivative tackifier resins.

Examples of the rosin-based tackifier resin include rosins such as gum rosin, wood rosin and tall oil rosin as well as stabilized rosins (e.g. stabilized rosins obtained by disproportionation or hydrogenation of the rosins), polymerized rosins (e.g. multimers, typically dimers, of the rosins) and modified rosins (e.g. unsaturated acid-modified rosins obtained by modification with an unsaturated acid such as maleic acid, furnaric acid or (meth)acrylic acid).

Examples of the rosin derivative tackifier resin include esterification products of the rosin-based tackifier resins (e.g. rosin esters such as stabilized rosin esters and polymerized rosin esters), phenol modification products of the rosin-based resins (phenol-modified rosins) and their esterification products (phenol-modified rosin esters).

Examples of the petroleum-based tackifier resin include aliphatic petroleum resins, aromatic petroleum resins, copolymeric petroleum resins, alicyclic petroleum resins and their hydrogenation products. Examples of the terpene-based tackifier resin include a-pinene resins, P-pinene resins, aromatic group-modified terpene-based resins, and terpene-phenol resins. Examples of the ketone-based tackifier resin include ketone- based resins resulting from condensation of ketones (e.g. aliphatic ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetophenone, etc.; alicyclic ketones such as cyclohexanone, methyl cyclohexanone, etc.) with formaldehyde.

In addition to the base polymer and the tackifying agent, the pressure-sensitive adhesive composition may further comprise any suitable additive within such a range as not to impair the effects of the present invention. Examples of additives include, but not limited to, a crosslinking agent, a crosslinking catalyst, a thickening agent, a stabilizing agent, a UV-absorbing agent, a filler, an antioxidant, an antistatic agent, a pigment, a dye and a silane coupling agent.

The first pressure-sensitive adhesive layer (111) and the second pressure-sensitive adhesive layer (112) of the pressure-sensitive adhesive film (110) may be formed of same or different pressure-sensitive adhesive composition as long as the adhesive strength of the pressure-sensitive adhesive layers (111, 112) falls within the preferred range. Furthermore, the first pressure-sensitive adhesive layer (111) and the second pressure-sensitive adhesive layer (112) of the pressure-sensitive adhesive film (110) may have identical or different thickness. Hence, the first pressure-sensitive adhesive layer (111) and the second pressure-sensitive adhesive layer (112) of the pressuresensitive adhesive film (110) may have identical or different adhesive strength.

Preferably, the flexible sheet (120) can be made of any one or any combination of a plastic material, a non-plastic material and a biomaterial. The plastic material includes thermoplastic material, thermosetting material, or the like. The non-plastic material includes paper, fabric or the like. The biomaterial includes biomaterial made from metal, ceramic, polymer, glass, or the like. These materials may be recyclable, biodegradable and/or derived from plant. The flexible sheet (120) can be made of any plastic material, non-plastic material and/or biomaterial within such a range as not to impair the effects of the present invention. In a preferred embodiment of the invention, the flexible sheet (120) is made of a thermoplastic material. Examples of thermoplastic material include, but not limited to, acrylic, polyester, polypropylene, polystyrene, nylon and Teflon. More preferably, the flexible sheet (120) is made of polyester. Most preferably, the flexible sheet (120) is made of polyethylene terephthalate.

The flexible sheet (120) of the present invention is preferred to be a flat sheet that can be bent in certain manner without breaking easily. The flexible sheet (120) may have an elongation at break in the machine direction (MD) and in the transverse direction (TD) of 1 % to 250 % and an elastic modulus in the machine direction (MD) and in the transverse direction (TD) of about 3 GPa to 10 GPa. In an embodiment of the invention in which the flexible sheet (120) is made of a plastic material or a polymer-based biomaterial, the flexible sheet (120) may have a tensile strength in the machine direction (MD) and in the transverse direction (TD) of about 200 MPa to 300 MPa. The flexible sheet (120) may have an elongation at break in the machine direction (MD) and in the transverse direction (TD) of 150 % to 250 %. The flexible sheet (120) may have an elastic modulus in the machine direction (MD) and in the transverse direction (TD) of about 4.4 GPa to 4.9 GPa. In an embodiment of the invention in which the flexible sheet (120) is made of a paper material or a paper-based biomaterial, the flexible sheet (120) may have a tensile strength in the machine direction (MD) and in the transverse direction (TD) of about 0.05 MPa or more. The flexible sheet (120) may have an elongation at break in the machine direction (MD) and in the transverse direction (TD) of 1 % to 6 %. The flexible sheet (120) may have an elastic modulus in the machine direction (MD) and in the transverse direction (TD) of about 3.0 GPa to 6.0 GPa.

The shape of the flexible sheet (120) is not particularly limited. The thickness of the flexible sheet (120) is not particularly limited. Preferably, the thickness of the flexible sheet (120) is about 10 pm to 300 pm to ensure adequate tensile strength and elongation at break. More preferably, the thickness of the flexible sheet (120) is about 40 pm to 150 pm.

The overall thickness of the pressure-sensitive adhesive sheet (100) includes the flexible sheet (120) and each layer of the pressure-sensitive adhesive film (110) other than the release liner (114). The overall thickness of the pressure-sensitive adhesive sheet (100) is not particularly limited. Preferably, the overall thickness of the pressuresensitive adhesive sheet (100) is about 23 pm to 450 pm. More preferably, the overall thickness of the pressure-sensitive adhesive sheet (100) is about 120 pm to 215 pm. The pressure-sensitive adhesive sheet (100) exhibits adequate adhesive strength, tensile strength and tear strength when the overall thickness falls within the range of 23 pm to 450 pm.

The pressure-sensitive adhesive sheet (100) of the present invention is designed to be removably adhered to an inner surface (210a) of the at least one edge (210) of the flexible clothing (200) and the pressure-sensitive adhesive sheet (100). Preferably, the inner surface (210a) of the edge (210) is an underside of an awning of the flexible clothing (200). Particularly, the pressure-sensitive adhesive sheet (100) is configured to bend according to a desired shape along an interior contour of the flexible clothing (200) without breaking after being adhered to the inner surface (210a) of the at least one edge (210) of the flexible clothing (200). Preferably, the pressure-sensitive adhesive sheet (100) of the present invention has a tensile strength of 0.05 MPa to 300.00 MPa. More preferably, the pressure-sensitive adhesive sheet (100) of the present invention has a tensile strength of 80 MPa to 165 MPa. Preferably, the pressure-sensitive adhesive sheet (100) has an elongation ratio of 1% to 400%. More preferably, the pressuresensitive adhesive sheet (100) of the present invention has an elongation ratio of 100% - 300%.

Figure 2 is a schematic sectional view of a pressure-sensitive adhesive sheet (100) according to the preferred embodiment of the invention being adhered to a flexible clothing (200). In Figure 2, the pressure-sensitive adhesive sheet (100) having a backing material (113), a first pressure-sensitive adhesive layer (111), a second pressuresensitive adhesive layer (112) and a flexible sheet (120) is removably bonded to a flexible clothing (200). In particular, the first pressure-sensitive adhesive layer (111) is coated on one surface (113a) of the backing material (113) and forms a first adhesive surface (Illa), the second pressure-sensitive adhesive layer (112) is coated on the other surface (113b) of the backing material (113) and forms a second adhesive surface (112b), the flexible sheet (120) is adhered to the first adhesive surface (Il la) and the second adhesive surface (112a) is adhered to an surface of the flexible clothing (200) . Any other suitable layer, such as a primer layer, may be formed between the backing material (113) and the first pressure-sensitive adhesive layer (111) and/or between the backing layer (113) and the second pressure-sensitive adhesive layer (112) within such a range as not to impair the effects of the present invention.

An embodiment in which the pressure-sensitive adhesive sheet (100) of the invention is applied onto a head covering (200) is depicted in Figure 3 and Figure 4. Figure 3 illustrates the steps to apply the pressure-sensitive adhesive sheet (100) on the head covering (200) while Figure 4 illustrates the head covering (200) before and after the application of the pressure-sensitive adhesive sheet (100) onto the at least one edge of the head covering (200). Figure 3 shows that in order to apply the pressure-sensitive adhesive sheet (100) onto the head covering (200), the release liner (114) affixed to the exposed second adhesive surface (112a) of the pressure-sensitive adhesive sheet (100) is removed and the exposed second adhesive surface (112a) is adhered to the underside of an edge of the head covering. As shown in Figure 4 (a), the edge of the head covering that is not in contact or supported by a user’s body collapses in the absence of the pressure-sensitive adhesive sheet (100). Figure 4 (b) shows that after the pressuresensitive adhesive sheet (100) is adhered onto the collapsed edge of the head covering (200) and is configured to bend according to a desired shape along an interior contour of the head covering (200), the edge of the head covering (200) is prevented from collapsing and the desired shape of the head covering is retained. The dotted circles in Figures 3 and 4 indicate the position of the pressure-sensitive adhesive sheet (100) on the underside of the head covering.

The present invention also relates to a flexible clothing (200) having at least one edge (210). Particularly, the flexible clothing (200) is a flexible head covering. The flexible clothing (200) can be made of a fabric material selected from a natural material, a synthetic material or a combination thereof. Examples of fabric material suitable for use as flexible clothing (200) include, but not limited to, cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey, velvet, sateen, gingham, chenille fabric, organza, denim, fleece, tartan, taffeta, damask, tweed, velour, terrycloth, gauze, organdie, corduroy, brocade, felt, challis, flannel, and the like. Preferably, the fabric material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.

In the preferred embodiment of the invention, the flexible clothing (200) comprises at least one pressure-sensitive adhesive sheet (100) as set forth in the preceding description. The at least one pressure-sensitive adhesive sheet (100) comprises a pressure-sensitive adhesive film (110) having a first adhesive surface (Illa) and a second adhesive surface (112a), and a flexible sheet (120) adhered to the first adhesive surface (Illa). The second adhesive surface (112a) of the pressure-sensitive adhesive sheet (100) is removably adhered to an inner surface (210a) of the at least one edge (210) of the flexible clothing (200) and the pressure-sensitive adhesive sheet (100) is configured to bend according to a desired shape along an interior contour of the flexible clothing (200) such that the at least one edge (210) of the flexible clothing (200) is prevented from collapsing or deformation when the at least one edge of the flexible clothing (200) is not in contact or supported by a user’s body.

According to a preferred embodiment, the edge (210) can be an awning of a head covering, collar, yoke, and cuffs. In an example of a head covering such as a hijab, the pressure-sensitive adhesive sheet (100) is adhered to the underside of the awning and bent according to a desired shape to form and retain the shape of the awning.

The present invention may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be considered in all aspects only as illustrative and not restrictive. The scope of the invention is, therefore indicated by the appended claims rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the claims, are to be embraced within their scope.

EXAMPLE

An example is provided below to illustrate different aspects and embodiments of the invention. The example is not intended in any way to limit the disclosed invention, which is limited only by the claims.

Example 1 : Preparation of the pressure-sensitive adhesive sheet

In 100 parts of ion-exchanged water, a monomer mixture formed of 85 parts of 2EHA, 13 parts of MA, 1.2 parts of AA, 0.8 part of MAA and 0.02 part of 3- memaciyloxypropyltrimethoxysilane (trade name KBM-503 available from Shin-Etsu Chemical Co., Ltd.); 0.048 part of a tertiary lauryl mercaptan (chain transfer agent); and 2.0 part of an emulsifier to prepare an aqueous emulsion of the monomer mixture (monomer emulsion) were mixed and emulsified. As the emulsifier, a sodium polyoxyethylene alkyl ether sulfate (trade name LATEMULE E-l 18B available from Kao Corporation) was used.

The monomer emulsion was added to a reaction vessel equipped with a condenser, nitrogen inlet, thermometer and stirrer, and was allowed to stir at room temperature for at least one hour under a nitrogen flow.

Subsequently, the system was heated to 60 °C. Then, 0.1 part of 2,2'-azobis[N-(2- carboxyethyl)-2-methylpropionamidine]hydrate (polymerization initiator) (trade name "VA-057" available from Wako Pure Chemical Industries, Ltd.) was added to the reaction vessel. While keeping the system at 60 °C, the monomer emulsion was reacted for six hours. After the system was cooled to room temperature, 10 % ammonia water was added to pH 7.5 in order to obtain a water dispersion of acrylic polymer (base polymer). This acrylic polymer has a Tg of about -60 °C when determined by the Fox equation.

To the water dispersion of acrylic polymer, based on non-volatiles, 30 parts of tackifier resin to 100 parts of the acrylic polymer was added in the water dispersion. Using 10 % ammonia water as pH-adjusting agent and polyacrylic acid (aqueous solution, 36 % non-volatiles) as thickener, the pH was adjusted to about 7.5 and the viscosity to about 9 Pa-s. As for the tackifier resin, an aqueous terpene phenol dispersion (trade name Tamanol E-200NT available from Arakawa Chemical Ind., Ltd.) was used. A water- dispersed acrylic pressure-sensitive adhesive (PSA) composition was thus obtained.

The resulting PSA composition was applied onto the release face of polyethylene terephthalate (PET) release film having a release face on one side and allowed to dry at 120 °C for 3 minutes to form a 50 pm thick PSA layer on the release face. As a backing material, a 25 pm thick PET film having an about 10 nm to 70 nm thick urethane-based primer layer on one face was used. A PSA film (110) according to the present invention was fabricated using the release films having PSAlayers and the backing material (113) using transfer method. The PSA layer (ie. the first PSA layer (111, IF)) on one release film was adhered to the primer layer face (113a) of the backing material (113) while the PSAlayer (ie. the second PSA layer (112, 2F)) on another release film was adhered to the other face (113b) of the backing material (113).

The release film of the PSA layer (111) was removed and the PSA layer (111) was adhered to a surface of the PET sheet (120). A pressure-sensitive adhesive sheet (100) according to the present invention was obtained. The pressure-sensitive adhesive sheet (100) were ensured to be laminated uniformly, clean cut; free from deformation, wrinkle and adhesive irregularities.

Example 2: Measurement of thickness

The pressure-sensitive adhesive film (110) and the pressure-sensitive adhesive sheet (100) prepared in Example 1 were cut into samples of 10 mm width and 250 mm length. The thickness of the samples were measured using a dial gauge according to the method as set forth in Standard JIS Z 1528:2004. The measurement was repeated 3 times and the average thickness of the pressure-sensitive adhesive film (110) and the pressuresensitive adhesive sheet (100) were recorded in Table 1 and Table 2, respectively.

Example 3 : Measurement of adhesive strength

The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 150 mm length. The adhesive strength of the samples on surfaces including stainless steel and fabric such as cotton, chiffon, satin and silk was measured using a tensile tester (Universal Tensile Testing Machine AG-IS Series, model AG-X series 50N available from Shimadzu) according to the method as set forth in Standard JIS Z 1528:2004.

The second adhesive surface (112a) of the pressure-sensitive adhesive sheet sample is adhered to a stainless steel (SUS) plate and a 2 kg roller is applied onto the laminate at a speed of 5mm/sec round trip. The laminate was left for more than 20-40 minutes then a 180° peeling of the pressure-sensitive adhesive sheet sample was conducted at the speed of 300mm/min.

The measurement was repeated 3 times and the average adhesive strength of the second adhesive surface (112a) of the pressure-sensitive adhesive sheet (100) were recorded in Table 1.

Example 4: Measurement of liner peel strength

The pressure-sensitive adhesive film (110) was cut into samples of 10 mm width and 150 mm length. The liner peel strength of the samples was measured using a tensile tester (Universal Tensile Testing Machine AG-IS Series, model AG-X series 50N available from Shimadzu) according to the method as set forth in Standard TM0001 Method A.

A plain paper was adhered to the first adhesive surface (11 la) of the pressure-sensitive adhesive film sample. The sample was attached on the liner peeling jig and a 180° peeling of the plain paper was conducted at the speed of 300mm/min by peeling off release film on the second adhesive surface (112a).

The measurement was repeated 3 times and the average liner peel strength of the pressure-sensitive adhesive film (110) were recorded in Table 1.

Example 5: Measurement of anchoring strength

The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 100 mm length. The anchoring strength of the samples was measured using a tensile tester (Universal Tensile Testing Machine AG-IS Series, model AG-X series 50N available from Shimadzu). The second adhesive surface (112a) of the sample was laminated to the adhesive surface of a polyester pressure-sensitive adhesive tape (product number ELP BT-315 (NO.315) available from Nitto Denko) by using handroller. The resulting laminate was heat- sealed by using heat-seal machine with 130 °C x 60 second with 0.5 mPa pressure. The sample was left at room temperature for 30 minute and the second adhesive surface (112a) was scraped to create initial peeling between the second adhesive surface (112a) and the NO.315 adhesive. 180° peeling of the laminate was conducted at the speed of 300mm/min.

The measurement was repeated 3 times and the average anchoring strength of the pressure-sensitive adhesive sheet (100) were recorded in Table 2.

Example 6: Measurement of tensile strength and elongation

The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 200 mm length. The tensile strength and elongation at break of the sample were measured using a tensile tester (Universal Tensile Testing Machine AG-IS Series, model AG-X series 50N available from Shimadzu) according to the method as set forth in Standard JIS Z 1528:2003. The gripping interval was set at 125 mm while the peeling speed was set at 300 mm/min.

The measurement was repeated 3 times and the average tensile strength and elongation at break of the pressure-sensitive adhesive sheet (100) were recorded in Table 2.

Example 7: Assessment of reusability of the pressure-sensitive adhesive sheet

The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 250 mm length. The reusability of the pressure-sensitive adhesive sheet was assessed.

Cotton, chiffon, and satin or silk fabric (200) were cut into size 550 mm x 50 mm. The release line of the second adhesive surface (112a) was peeled off and the second adhesive surface (112a) was adhered onto each of the fabric in flat position. The resulting laminate was pressed lightly to enhance adhesion between the second adhesive surface (112a) and the fabric. The laminates were placed onto a dummy head and the ends of the fabric were secured with a mini pin. The laminates were left at room temperature for 4 hours. The mini pin was removed from dummy head and the laminate was placed in flat position. The pressure-sensitive adhesive sheet (100) was removed from the laminate and the second adhesive surface (112a) was placed on a paper release liner. The second adhesive surface (112a) and the fabric surface to which the second adhesive surface (112a) was adhered were observed.

The steps were repeated for three times by using the same pressure-sensitive adhesive sheet (100). The observation results were recorded in Table 2.

Example 8: Assessment of effect of ironing on the pressure-sensitive adhesive sheet The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 250 mm length. The effect of ironing on the pressure-sensitive adhesive sheet was assessed.

Cotton, chiffon, and satin or silk fabric (200) were cut into size 550 mm x 50 mm. The release line of the second adhesive surface (112a) was peeled off and the second adhesive surface (112a) was adhered onto each of the fabric in flat position. The resulting laminate was pressed lightly to enhance adhesion between the second adhesive surface (112a) and the fabric. The laminates were left at room temperature for 10 minutes. The laminate was ironed with medium heat by using a conventional iron or steam iron. Half portion of the pressure-sensitive adhesive sheet (100) was peeled-off immediately after the heat treatment while the other half portion of the pressuresensitive adhesive sheet (100) was peeled off 5 minutes after the heat treatment. The fabric surface to which the second adhesive surface (112a) was adhered was observed for any damage such as fur, tear, adhesive residue, etc.

The assessment was repeated for three times. The observation results were recorded in Table 2.

Example 9: Assessment of leave-on effect of the pressure-sensitive adhesive sheet The pressure-sensitive adhesive sheet (100) was cut into samples of 10 mm width and 250 mm length. The leave-on effect of the pressure-sensitive adhesive sheet was assessed.

Cotton, chiffon, and satin or silk fabric (200) were cut into size 550 mm x 50 mm. The release line of the second adhesive surface (112a) was peeled off and the second adhesive surface (112a) was adhered onto each of the fabric in flat position. The resulting laminate was pressed lightly to enhance adhesion between the second adhesive surface (112a) and the fabric. The laminates were separated into four group in which each group was left at room temperature for 12 hours, 24 hours, 3 days and 7 days, respectively. The pressure-sensitive adhesive sheets (100) were peeled-off from the laminates after the specified duration. The fabric surface to which the second adhesive surface (112a) was adhered was observed for any damage such as fur, tear, adhesive residue, etc.

Claims

1. A pressure-sensitive adhesive sheet (100) for providing support to at least one edge (201) of a flexible clothing (200), the pressure-sensitive adhesive sheet (100) comprising a pressure-sensitive adhesive film (110) having a first adhesive surface (I l la) and a second adhesive surface (112a); and a flexible sheet (120) adhered to the first adhesive surface (11 la), wherein the second adhesive surface (112a) of the pressure-sensitive adhesive sheet (100) is removably adhered to an inner surface (210a) of the at least one edge (210) of the flexible clothing (200) and the pressure-sensitive adhesive sheet (100) is configured to bend according to a desired shape along an interior contour of the flexible clothing (200) such that the at least one edge (210) of the flexible clothing (200) is prevented from collapsing or deformation when the at least one edge (210) of the flexible clothing (200) is not in contact or supported by a user’s body.

2. The pressure-sensitive adhesive sheet (100) according to claim 1, wherein the inner surface (210a) of the edge (210) is an underside of an awning of the flexible clothing (200).

3. The pressure-sensitive adhesive sheet (100) according to claim 1 or 2, wherein the second adhesive surface (112a) has an adhesive strength of 0.05 N/10 mm to 10.00 N/10 mm.

4. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to 3, wherein the first adhesive surface (I l la) has an anchoring strength to the flexible sheet (120) of 0.05 N/10 mm to 10.00 N/10 mm.

5. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to

4, wherein the flexible sheet (120) is made of a plastic material, a non-plastic material and a biomaterial.

6. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to

5, wherein the pressure-sensitive adhesive sheet (100) has a thickness of 23 pm to 450 pm.

7. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to

6, wherein the pressure-sensitive adhesive sheet (100) has a tensile strength of 0.05 MPa to 300.00 MPa.

8. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to

7, wherein the pressure-sensitive adhesive sheet (100) has an elongation ratio of 1% to 400%.

9. The pressure-sensitive adhesive sheet (100) according to any one of claims 1 to

8, wherein the flexible clothing (200) is made of a material selected from a natural material, a synthetic material or a combination thereof.

10. The pressure-sensitive adhesive sheet (100) according to claim 9, wherein the material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.

11. A flexible clothing (200) having at least one edge (210), the flexible clothing (200) comprising at least one pressure-sensitive adhesive sheet (100) having a pressure-sensitive adhesive film (110) having a first adhesive surface (I l la) and a second adhesive surface (112a); and a flexible sheet (120) adhered to the first adhesive surface (I l la), wherein the second adhesive surface (112a) of the pressure-sensitive adhesive sheet (100) is removably adhered to an inner surface (210a) of the at least one edge (210) of the flexible clothing (200) and the pressure-sensitive adhesive sheet (100) is configured to bend according to a desired shape along an interior contour of the flexible clothing (200) such that the at least one edge (210) of the flexible clothing (200) is prevented from collapsing or deformation when the at least one edge (210) of the flexible clothing (200) is not in contact or supported by a user’s body. 12. The flexible clothing (200) according to claim 11, wherein the flexible clothing

(200) is a flexible head covering made of a material selected from a natural material, a synthetic material or a combination thereof.

13. The flexible clothing (200) according to claim 12, wherein the material is selected from cotton, chiffon, silk, satin, ceruty babydoll, diamond crepe, voile, jersey or any combination thereof.