Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Adhesive outermost layer
Reexamination Certificate
1999-09-13
2003-02-04
Seidleck, James J. (Department: 1711)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Adhesive outermost layer
C428S522000, C428S523000, C524S394000, C524S398000, C524S399000, C524S400000, C524S450000, C602S042000, C602S043000, C602S046000, C602S054000, C602S058000
Reexamination Certificate
active
06514606
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pressure-sensitive adhesive sheet for skin adhesion comprising a backing film comprising a flexible vinyl chloride resin, and a pressure-sensitive adhesive layer provided on one side of the backing film, and its use. More particularly, the invention relates to a pressure-sensitive adhesive sheet for skin adhesion that an adhesive force of the pressure-sensitive adhesive on the backing film does not lower greatly even with the lapse of long term and substantially maintains the initial adhesive force, and to its use, for example, a use as a first-aid adhesive plaster.
2. Description of the Related Art
Conventionally, a pressure-sensitive adhesive sheet for skin adhesion comprising a flexible backing film having provided thereon a pressure-sensitive adhesive layer has been used as a dressing, a bandage or the like, and has also been widely used in homes as a first-aid adhesive plaster by providing an absorbent pad such as gauze at a central region on a surface of the pressure-sensitive layer. Further, an adhesive drug sheet for skin adhesion comprising a backing film having provided thereon a layer comprising a pressure-sensitive adhesive containing various drugs is used for various medical uses. Conventionally, a film comprising a so-called flexible vinyl chloride resin has widely been used as the backing film for such a pressure-sensitive adhesive sheet for skin adhesion from the points that it is flexible, has good adaptability to skin, and has excellent printability. In such a flexible vinyl chloride resin, a combination of a fatty acid calcium-fatty acid zinc type stabilizer and an epoxidized soybean oil has generally been used as a stabilizer from the standpoint of safety. However, when an acrylic pressure-sensitive adhesive, for example, is coated on a backing film comprising such a vinyl chloride resin to prepare an adhesive plaster, an adhesive force of the backing film decreases with the passage of time. Thus, where the adhesive force of the pressure-sensitive adhesive decreases, even if the adhesive plaster is adhered to a skin, an edge of the adhesive plaster lifts from the skin, and in some cases, the adhesive plaster peels off from the skin. As a result, the adhesive plaster may not exhibit the function as a first-aid adhesive plaster.
SUMMARY OF THE INVENTION
As a result of extensive investigations to overcome those problems in the conventional pressure-sensitive adhesive sheet for skin adhesion using a vinyl chloride resin film as a backing film, the inventors have found that in the conventional vinyl chloride resin film, an epoxidized soybean oil compounded as a plasticizer migrates from the backing film to the pressure-sensitive adhesive layer with the passage of time, thereby crosslinking or curing an acrylic pressure-sensitive adhesive, for example, and as a result, the pressure-sensitive adhesive loses its initial adhesive force, so that the adhesive force lowers with the passage of time.
Based on the above-described finding, the inventors also have made further investigation and found that when a polyester plasticizer is used as a plasticizer in place of the epoxidized soybean oil, and a combination of a metallic soap and a hydrotalcite is used as a stabilizer, a film produced by calendering has an excellent heat stability, and also found that when the film thus obtained is used as the backing film, and a pressure-sensitive adhesive is applied to one side of the backing film to form a pressure-sensitive adhesive sheet for skin adhesion, the plasticizer does not migrate into the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive sheet for skin adhesion can substantially maintain the initial adhesive force even with the lapse of long term. The present invention has been completed based on this finding.
Accordingly, one object of the present invention is to provide a pressure-sensitive adhesive sheet for skin adhesion including a backing film that has an excellent heat stability during its production by calendering and a pressure-sensitive adhesive layer coated on one side of the backing film, a pressure-sensitive adhesive in the adhesive layer does not lose adhesive force greatly so that the initial adhesive force is substantially maintained.
Another object of the present invention is to provide a first-aid adhesive plaster using the pressure-sensitive adhesive sheet for skin adhesion.
According to a first aspect, the present invention provides a pressure-sensitive adhesive sheet for skin adhesion, which comprises a backing film and a pressure-sensitive adhesive layer for skin adhesion formed on one side of the backing film, wherein the backing film comprises: 100 parts by weight of a vinyl chloride polymer; about 40 to about 70 parts by weight of a polyester plasticizer having a number average molecular weight of about 1,500 to about 3,000; a stabilizing effective amount of a stabilizer comprising at least one metallic soap selected from the group consisting of fatty acid calcium, fatty acid zinc and fatty acid barium; and about 0.1 to about 1.0 part by weight of hydrotalcite.
Here, the vinyl chloride polymer may be at least one polymer selected from a polymer of vinyl chloride alone and copolymers of vinyl chloride and an ethylenically unsaturated hydrocarbon having 2 to 4 carbon atoms.
The vinyl chloride polymer may be at lest one polymer selected from the group consisting of polyvinyl chloride and vinyl chloride/ethylene copolymers and vinyl chloride/vinyl acetate copolymer.
The vinyl chloride polymer may preferably have an average degree of polymerization of about 500 to about 1,500.
The polyester plasticizer may comprise a polyester obtained from an aliphatic or aromatic dicarboxylic acid having 2 to 10 carbon atoms and a glycol having 2 to 10 carbon atoms.
The polyester plastercizer may preferably have a number average molecular weight of about 1,500 to about 3,000.
The metallic soap may preferably be a combination of a fatty acid calcium and a fatty acid zinc.
The fatty acid in the metallic soap may be a saturated or unsaturated fatty acid having 12 to 20 carbon atoms.
The metallic soap may be in an amount of about 0.5 to about 2.5 parts by weight per 100 parts by weight of the vinyl chloride polymer.
The pressure-sensitive adhesive may preferably be an acrylic pressure-sensitive adhesive.
The acrylic pressure-sensitive adhesive may comprise a polymer comprising an alkyl acrylate having 4 to 12 carbon atoms in the alkyl moiety as a main monomer component.
The acrylic pressure-sensitive adhesive may further comprise at least one vinyl ester selected from the group consisting of alkyl (meth)acrylates having 1 to 3 carbon atoms in the alkyl moiety, vinyl acetate and N-methyl-2-pyrrolidone.
The acrylic pressure-sensitive adhesive may preferably comprise an acrylic pressure-sensitive adhesive that contains at least one of a hydroxyl group and a carboxyl group.
The acrylic pressure-sensitive adhesive may comprise a copolymer comprising an alkyl acrylate ester as a main monomer component and an hydroxyalkyl (meth) acrylate or (meth) acrylic acid as a comonomer copolymerizable therewith.
According to a second aspect, the present invention provides a first-aid adhesive plaster comprising the above-mentioned pressure-sensitive adhesive sheet for skin adhesion and an absorbent pad provided on a central region on a surface of the pressure-sensitive adhesive layer.
As described above, the pressure-sensitive adhesive sheet for skin adhesion according to the present invention comprises a backing film comprising a flexible vinyl chloride resin having compounded therewith a polyester plasticizer as a plasticizer, and hydrotalcite together with a metallic soap as a stabilizer, and a pressure-sensitive adhesive layer provided on one side of the backing film, and also the first-aid adhesive plaster of the present invention uses such a pressure-sensitive adhesive sheet for skin adhesion, so that the pressure-sensitive adhesive does not show a great decrease in adhe
Kinoshita Takashi
Kuniya Masayoshi
Sasaki Yasuyuki
Bissett Melanie
Nitto Denko Corporation
Seidleck James J.
Sughrue & Mion, PLLC
LandOfFree
Pressure-sensitive adhesive sheet for skin adhesion and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure-sensitive adhesive sheet for skin adhesion and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure-sensitive adhesive sheet for skin adhesion and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3135961