Toyo Seikan Kaisha, Ltd.

Japan Crown Cork Co Ltd.

Isao Ichinose

Fumio Mori

Noboru Suzuki

Go Kunimoto

Osamu Ishii

Junichi Itsubo

Takashi Yazaki

Koichi Doi

Katsuhiko Kitakawa

Tetsuomi Ogimoto

Mitsuhiro Sakemoto

Katsuake Tanaka

A pilferproof plastic closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall. A circumferential weakening line extending circumferentially is formed in the skirt wall, and the skirt wall is divided into a main portion above the weakening line and a pilferproof bottom portion beneath it. An internal thread to be screwably fitted with an external thread formed on the mouth-neck portion of a container is formed on the inner surface of the main portion, and a plurality of radially inwardly projecting and circumferentially spaced engaging flaps are formed on the inner surface of the pilferproof bottom portion. An axial breaking line is formed in the pilferproof bottom portion which extends downwardly from the upper end of the pilferproof bottom portion but is non-existent in at least a greater portion of the lower part of the pilferproof bottom portion. At least a greater portion of the base edge of each of the engaging flaps is positioned in the aforesaid lower part where the axial breaking line does not exist.

Plastic container closure having pilferproof characteristics

A peelable adhesive structure is disclosed which comprises a plurality of parts at least one of which is made of metal, adhering together by means of a coating, characterized in that said coating has a peelable surface formed between a first layer of a denatured hydrocarbon resin or denatured hydrocarbon resin composition having an acid value of from 0.1 to 20 and a second layer containing an epoxy resin.

Peelable adhesive structure

A closure cap having a liner adhered to a cap shell by a plurality of coating layers. Prize markings are printed on one of the coating layers and are positioned between the coating layers. The peel resistance in the interface between the coating layers is less than that between the topmost coating layer and the liner to assure that the prize markings will be transferred to the liner when the liner is peeled from the cap shell. The liner includes a starting portion which adheres to the topmost coating layer only slightly to facilitate easy removal of the liner from the cap shell.

Closure cap having prize markings and peelable liner

A peelable bonded structure having a peel strength of 0.05 to 5 kg/cm comprises a plurality of articles, at least one of which is made of metal, bonded together through a composite coating layer. The composite coating layer is composed of adjacent first and second coating layers at least one of which comprises (A) a modified olefin resin having a carbonyl group concentration of 0.01 to 200 milliequivalents per 100 g of the olefin resin and (B) a coating film-forming base resin at an (A)/(B) weight ratio of from 0.2/99.8 to 40/60 and has a multi-layer distribution structure having resin concentration gradients in the thickness direction such that the modified olefin resin (A) is distributed predominantly in the portion contiguous to the interface between the two coating layers and the base resin (B) is distributed predominantly in the opposite portion.

Peelable bonded structures and process for preparing same

A container cap having a coated metal shell. A peelable adhesive layer joins a liner to the shell. The peelable adhesive layer comprises a local coating resin layer having a diameter less than that of the metal shell and a layer of an epoxy resin.

Container cap having a peelable liner

A container closure for use in packaging flowable materials is disclosed comprising a closure shell, a peelable thermoplastic liner disposed on the inner surface of the shell and having a thick periphery and a comparatively thin central portion with a demarcated peeling tab extending to the periphery of the liner, and at least one adhesive interfacial layer separating the liner from and peelably bonding said liner to the shell and having a non-adhesive or weakly adhesive zone underlying and corresponding to the periphery of the liner and a relatively strongly adhesive zone underlying and corresponding to the central portion of the liner.

Container cover with peelable liner

When a polyolefin layer is bonded to a metal substrate through a primer layer, if a polar group-containing ethylenically unsaturated monomer-modified olefin resin (A) having a specific polar group concentration and a specific degree of crystallinity and a coating film-forming base resin (B) are incorporated at a specific ratio into a specific mixed solvent to form a paint and the primer layer is formed by using this paint, there is obtained a novel multi-layer distribution structure comprising the base resin distributed predominantly in the portion of the primer layer contiguous to the surface of the metal substrate and the modified olefin resin distributed predominantly in the portion of the primer layer contiguous to the polyolefin layer and having a concentration gradient of the two components (A) and (B) in the thickness direction. By virtue of the presence of this primer layer, the bonding strength between the metal substrate and the polyolefin and the corrosion resistance of the metal substrate as well as the processability of the polyolefin-metal bonded structure are substantially improved.

Polyolefin-metal bonded structures and process for preparing same

A peelable bonded structure comprising a metal substrate and a polyolefin layer bonded to the substrate through a primer layer, wherein the primer layer is a composition comprising (A) a modified olefin resin having a carbonyl group concentration of 0.01 to 200 milliequivalents per 100 g of the olefin resin and (B) a coating film-forming base resin at an (A)/(B) weight ratio of from 0.1/99.8 to 70/30. The primer layer has in at least one first planar region thereof a multi-layer distribution structure having a resin concentration gradient in the thickness direction such that the modified olefin resin (A) is distributed predominantly in the portion of the primer layer contiguous to the polyolefin layer and the base resin (B) is distributed predominantly in the portion of the primer layer contiguous to metal substrate, and in at least one second planar region the modified olefin resin (A) is distributed in the portion of the primer layer contiguous to the polyolefin layer at a lower distribution ratio.

A crown closure having a polyolefin liner that can be readily removed, said crown closure comprising a crown shell having a primer layer on its inner surface and a polyolefin liner applied to the inside of said crown shell, characterized in that said primer layer is a two-component priming consisting of an undercoat layer containing a polyethylene oxide and a topcoat layer containing a polyethylene oxide and at least one other compatible resin, with the provision of a printing layer of indicia at the interface between said undercoat and topcoat layers or atop said topcoat layer. Aforesaid crown closure can be prepared by providing at one face of a metal stock sheet a primer undercoat layer containing a polyethylene oxide, printing indicia thereon, providing atop said undercoat layer a primer topcoat layer containing a polyethylene oxide and at least one other compatible resin, and thereafter forming said metal stock sheet into crown shells in such a manner that said coating layers come to the inside of the shells followed by depositing a polyolefin mass in said shells and molding same into the form of liners.

Growing community of inventors

Hiratsuka, Japan

Isao Ichinose