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  Crosslinkable pressure-sensitive adhesive for skinRelated Patent Categories: Drug, Bio-affecting And Body Treating Compositions, Preparations Characterized By Special Physical Form, Web, Sheet Or Filament Bases; Compositions Of Bandages; Or Dressings With Incorporated Medicaments, Bandages With Incorporated Medicaments, Pressure Sensitive Adhesive MeansThe Patent Description & Claims data below is from USPTO Patent Application 20070196455. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001] The present invention relates to a crosslinkable pressure-sensitive adhesive for skin, to a crosslinkable pressure-sensitive adhesive sheet for skin employing it, to a composition for production of the crosslinkable pressure-sensitive adhesive for skin and to a process for production of the crosslinkable pressure-sensitive adhesive for skin. BACKGROUND ART [0002] Pressure-sensitive adhesive sheets for skin, in general, must reliably adhere for about 24 hours after being attached to skin and must also adhere without peeling during perspiration and bathing. Also for removal, they must be peelable with a degree of force that does not cause pain, and if the adhesion is stronger than necessary it can result in plucking of hairs and peeling of the corneum, as well as mechanical skin irritation by pulling of the skin. Consequently, this creates erythema that may persist for several days even after peeling, and therefore it is necessary to minimize this inconvenience. Moreover, it is important that no pressure-sensitive adhesive remain on the skin surface after the pressure-sensitive adhesive sheet has been removed from the skin. [0003] Crosslinking of acrylic pressure-sensitive adhesives has been commonly employed in the prior art in pressure-sensitive adhesives for skin in order to improve cohesion of the pressure-sensitive adhesives. Such crosslinking is achieved almost entirely by using the acrylic acid in an acrylic copolymer, but its drawbacks include the facts that (1) the adhesion is excessively strong or chemical activity of the acrylic acid causes significant skin irritation, (2) in percutaneous absorption preparations containing drugs, the acrylic acid and basic drug interact and impede migration of the drug from the pressure-sensitive adhesive into the skin, thereby reducing the percutaneous absorption, and (3) polyisocyanate used as the crosslinking agent is highly active and often reacts with drugs, thereby impairing drug stability. [0004] In Japanese Patent Laid-open (Kokai) Publication SHO No. 61-100520 there is proposed an acrylic acid-free pre-crosslinked pressure-sensitive adhesive, which comprises 45 mol % 2-ethylhexyl acrylate, 20-55 mol % vinylpyrrolidone and no greater than 35 mol % of an acrylic acid ester with 3-12 carbon atoms in the ester portion, as well as 0.005-0.5 wt % of a polyfunctional monomer with respect to the weight of the entire monomer. However, while percutaneous absorption preparations using this type of pressure-sensitive adhesive have satisfactory drug percutaneous absorption and stability, the cohesive strength is insufficient when softening agents and plasticizers are added to improve the drug release property, and therefore adhesive residue remains on the skin after the percutaneous absorption preparation is removed. Thus, the problem of adhesive residue must be solved in order to obtain excellent pressure-sensitive adhesive sheets for skin. [0005] As modifications to crosslinking acrylic-based pressure-sensitive adhesives there have been proposed methods of obtaining pressure-sensitive adhesive sheets by crosslinking after coating and drying acrylic copolymer composition solutions containing large amounts of plasticizers, and specifically there may be mentioned Japanese Patent Publication No. 2700835 and Japanese Patent Publication No. 3014188. With such percutaneous absorption preparations, however, it is possible to increase the shape retention of the pressure-sensitive adhesive layer but difficult to design a preparation with balance between adhesion on the skin and cohesive force of the pressure-sensitive adhesive. [0006] On the other hand, Japanese Patent Laid-open (Kohyo) Publication No. 2002-535475 proposes a method wherein an acrylic-based pressure-sensitive adhesive containing diacetoneacrylamide, and a plasticizer, are mixed with a polyamine such as adipic acid dihydrazide or hexanediamine, the mixture is coated and then the solvent is heated and dried for crosslinking. However, the drawbacks of this method are the following: (1) Mixture of the low-molecular polyamine such as adipic acid dihydrazide or hexanediamine with the pressure-sensitive adhesive solution results in a coating mixture that gels within several hours and becomes impossible to coat. [0007] (2) Low molecular polyamines such as adipic acid dihydrazide and hexanediamine crosslink the diacetoneacrylamide-containing acrylic-based pressure-sensitive adhesive when no drug is present, but in the presence of a drug they react therewith or the drug often interferes, thereby preventing crosslinking. [0008] (3) Adipic acid dihydrazide has low organic solvent solubility, and therefore must be used as a solution in water for addition to the coating solution. Consequently, its use in a large amount promotes precipitation of polymers and renders handling inconvenient. (4) Hydrazine compounds such as adipic acid dihydrazide are absorbed through the skin and are indicated as a toxicity risk, for which reason they have been unsuitable as additives for pressure-sensitive adhesives on skin. [Patent document 1] Japanese Patent Laid-open (Kokai) Publication SHO No. 61-100520 [Patent document 2] Japanese Patent Publication No. 2700835 [Patent document 3] Japanese Patent Publication No. 3014188 [Patent document 4] Japanese Patent Laid-open (Kohyo) Publication No. 2002-535475 DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention [0009] In light of the above, it is an object of the present invention to provide a crosslinkable pressure-sensitive adhesive for skin having satisfactory adhesive and release properties for human skin and low irritation against skin, as well as a crosslinkable pressure-sensitive adhesive for skin that is suitable for medical or cosmetic use, and it is another object of the invention to provide a composition for production of a crosslinkable pressure-sensitive adhesive for skin with excellent shelf life, which is suitable for production of the aforementioned crosslinkable pressure-sensitive adhesive for skin. MEANS FOR SOLVING THE PROBLEMS [0010] The crosslinkable pressure-sensitive adhesive for skin of the invention is formed by 100 parts by weight of an acrylic copolymer (copolymer A) comprising a (meth)acrylic acid alkyl ester as the main constituent component and 3-45 wt % diacetoneacrylamide as an essential constituent component, and containing no free carboxyl groups, and 0.1-30 parts by weight of an acrylic copolymer (copolymer B) comprising a (meth)acrylic acid alkyl ester as the main constituent component and a primary amino group and/or carboxyhydrazide group on a side chain, and containing no free carboxyl groups. The primary amino group and/or carboxyhydrazide on the side chain of copolymer B participates in crosslinking reaction with the carbonyl group of the diacetoneacrylamide in copolymer A, and it therefore functions as a crosslinking agent as well as a constituent component of the pressure-sensitive adhesive. Thus, it is an important feature of the crosslinkable pressure-sensitive adhesive for skin that crosslinking is possible without using a low molecular crosslinking agent. [0011] A first example of copolymer B is an acrylic copolymer obtained by copolymerizing a (meth)acrylic acid alkyl ester as the main constituent component with a (meth)acrylic monomer having a primary amino group on a side chain. [0012] A second example of copolymer B is an acrylic copolymer obtained by copolymerizing a (meth) acrylic acid alkyl ester as the main constituent component with (meth) acrylic acid, and then reacting the free carboxyl group in the obtained copolymer with an imine, diamine and/or dicarboxylic acid dihydrazide. [0013] A third example of copolymer B is an acrylic copolymer obtained by copolymerizing a (meth) acrylic acid alkyl ester as the main constituent component with diacetoneacrylamide, and then reacting the carbonyl group in the obtained copolymer with a diamine and/or dicarboxylic acid dihydrazide. [0014] The crosslinkable pressure-sensitive adhesive for skin of the invention which is formed on a sheet-like support is used as a medical patch. The crosslinkable pressure-sensitive adhesive sheet for skin may be manufactured by dissolving 100 parts by weight of copolymer A and 0.1-30 parts by weight of copolymer B in a solvent, and then evaporating off the solvent by heat according to a publicly known method. In this process, 25-200 parts by weight of a plasticizer with respect to 100 parts by weight of copolymer A, or a percutaneous absorbing medical component and/or cosmetic ingredient, percutaneous absorption accelerator, aromatic or the like may also be added. Continue reading... Full patent description for Crosslinkable pressure-sensitive adhesive for skin Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Crosslinkable pressure-sensitive adhesive for skin patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Crosslinkable pressure-sensitive adhesive for skin or other areas of interest. ### Previous Patent Application: Compositions and methods for treating dermatitis or psoriasis Next Patent Application: Smart patch Industry Class: Drug, bio-affecting and body treating compositions ### FreshPatents.com Support Thank you for viewing the Crosslinkable pressure-sensitive adhesive for skin patent info. 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