Idemitsu Petrochemical Co., Ltd.

Kenichi Tanaka

Masao Takashige

Hiroshi Odaka

Shuichi Goto

Yoshikazu Shirai

Each base for fusing a snap-zipper male member and a snap-zipper female member, which form a snap zipper, onto a bag body is formed from a mixture of polypropylene and an ethylene copolymer obtained by copolymerizing ethylene and an .alpha.-olefin having a carbon atom ratio of 3 to 20, in which the ethylene copolymer has a weight average molecular weight/number average molecular weight of less than 3, density in the range from 0.850 g/cm.sup.3 to 0.935 g/cm.sup.3, melt index in the range from 0.3 g/10 min. to 15 g/10 min., and range of number of branching dependent on molecular weight of 0-5 branches/1,000 carbon. A bag with the snap zipper is structured to fuse the snap zipper through the bases onto the bag body.

Snap zipper and a bag with the same

A snap-zipper 10 comprises a male and a female member 11 and 12 having strip-like bases 21 and 22 for fusion bonding, the bases being made of an ethylene.multidot..alpha.-olefin copolymer with a MI of 0.3 to 15 g per 10 min., a density of 0.850 to 0.935 g/ml, a molecular weight distribution of 2 to 5, a molecular-weight-dependent width of branch number of 0 to 5 per 1,000 carbon atoms, an olthodichloroenzene soluble component content of 10% by weight or below, and a maximum melting point determined with a differential scan calorimeter of 115.degree. C. or below. A bag 30 with a snap-zipper is obtained by fusion bonding the stems 21 and 25 of the snap-zipper 10 to a bag body 31.

Snap-zipper and bag with the same

A snap-fastener bag according to the present invention is composed of a quadrilateral bag body, a deaerating passage provided along a bottom-seal and a snap fastener provided along the opening. The deaerating passage is provided by configurating a deaerating passage opening as a non-adhesive part through one side-seal and along the bottom-seal and by configurating an adhesive part near the bottom of the side-seal to near the other side-seal positioned at a predetermined interval from the bottom-seal in parallel to adhere between the top and bottom films. A paint film coated with a sticky substance having the kinematic-viscosity of 4-5,000.times.10.sup.-6 m.sup.2 /s (100.degree. C.) such as polybutene is applied in the deaerating passage.

Snap-fastener bag

A snap fastener having a male strip member and a female strip member, mutually engaged and respectively having a band-like base portion and a snapping portion having a snapping function, in which the band-like base portion includes a first layer fused onto a bag body; a second layer laminated onto the first layer; and a third layer laminated onto the second layer, and further the first layer is consisted of a resin film fusing the inner-most layer of the bag body, the second layer consists of a biaxially oriented film, the third layer consists of a resin film fusing the snapping portion, and the snapping portion consists of synthetic resin having a melt index (MI) of 1-20 g/10 min. At least one layer of the biaxially oriented nylon film consists 40-85% by weight of nylon 6 (Ny 6) and 15-60% by weight of metaxylylene adipamide (MXD 6), in which both magnifications of the MD direction (the moving direction of the film) and the TD direction (the direction of the width of the film) in extending are more than 2.8 times.

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Himeji, Japan

Kenichi Tanaka