摘要:
The present invention is based on the finding that when a multi-layer blow-formed body is heat-treated, cooled and taken out, an intermediate layer of a gas-barrier resin in the multi-layer blow-formed body acts as a heat-insulating layer and if the blow-formed body is cooled from the interior by a cooling fluid, a shape-retaining property necessary for taking out the blow-formed body from the mold can be promptly obtained. A biaxially drawn polyester vessel excellent in the resistance to thermal contraction and gas-barrier properties can be prepared at a high manufacturing speed with a reduced number of steps by preheating or temeprature-adjusting a multi-layer preform comprising inner and outer layers of a polyester composed mainly of ethylene terephthalate units and at least one intermediate layer composed of a gas-barrier resin to a temperature suitable for drawing, carrying out the biaxial draw-blow forming of the preform and the heat treatment of the blow-formed body in a mold maintained at a heat-setting temperature, changing over a compressed fluid for the blow-forming to a fluid for internal cooling, cooling the blow-formed body to a temperature at which deformation is not caused when the blow-formed body is taken out from the mold, while contacting the blow-formed body with the surface of the mold cavity, and taking out the formed body from the mold.
摘要:
A transparent multi-layer container comprising a co-extrudate of an oxygen-barrier resin layer and an orienting resin layer which is monoaxially or biaxially oriented is disclosed. An adhesive resin layer is preferably interposed between the oxygen-barrier layer and the orienting resin layer, and this co-extrudate is drawn and molded at a specific temperature determined relatively to the melting points and softening points of the respective resins. This container is excellent in the combination of transparency, rigidity, mechanical strength, gas-barrier property and interlaminar peel strength.
摘要:
A molded container having a wall composed of a thermoplastic resin oriented in at least one direction on the wall face, wherein the container wall has a layer of a blend composed mainly of a plurality of melt-extrudable thermoplastic resins, each of which has a solubility parameter (Sp) of at least 9.5, at least one of said thermoplastic resins has an oxygen permeability lower than 5.times.10.sup.-11 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg, said thermoplastic resins are chosen so that the difference (.DELTA.Sp) of the solubility parameter in said thermoplastic resins is not greater than 4.5, the elongation of said resin blend is higher than the arithmetic mean (.epsilon.) of elongations of the respective thermoplastic resins, and wherein the container has a thermal shrinkability (.delta.) of at least 5% in the orientation direction of said container wall.
摘要:
A transparent multi-layer container comprising a co-extrudate of an oxygen-barrier resin layer and an orienting resin layer which is monoaxially or biaxially oriented is disclosed. An adhesive resin layer is preferably interposed between the oxygen-barrier layer and the orienting resin layer, and this co-extrudate is drawn and molded at a specific temperature determined relatively to the melting points and softening points of the respective resins. This container is excellent in the combination of transparency, rigidity, mechanical strength, gas-barrier property and interlaminar peel strength.
摘要:
A packaging material having an improved gas permeation resistance, which comprises at least one layer composed of (A) an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 50 to 75 mole % and a residual vinyl ester content of up to 4 mole % based on the sum of the vinyl alcohol and vinyl ester or (B) a blend of said ethylene-vinyl alcohol copolymer with up to 150% by weight, based on said copolymer, of at least one thermoplastic polymer other than said copolymer, said ethylenevinyl alcohol copolymer having a main endothermic peak satisfying substantially the following requirement:Y.sub.1 = 1.64X + 68.0wherein Y.sub.1 stands for the main endothermic peak temperature (.degree. C.) in the differential thermal analysis, and X stands for the vinyl alcohol content (mole %) in the ethylene-vinyl alcohol copolymer,And at least one subsidary endothermic peak satisfying substantially the following requirement:0.67 X + 76.7 .gtoreq. Y.sub.2 .gtoreq. 0.40 X + 40.0preferably0.67 X + 76.7 .gtoreq. Y.sub.2 .gtoreq. 0.34 X + 88.0wherein Y.sub.2 stands for the subsidary endothermic peak temperature (.degree. C.) in the differential thermal analysis, and X is as defined above,The ratio (Rs) of the subsidary endothermic peak area to the main endothermic peak area being at least 2.5%.
摘要:
In a multi-layer blow molded container having a joint portion at least in the bottom portion thereof, barrier characteristics to gases such as oxygen and water vapor and liquids such as water, solvents, aqueous ammonia and salt water and interlaminar strength characteristics such as interlaminar adhesion strength, peel strength and impact strength in the content-filled state can be highly improved by blow molding a parison of a laminate structure of two or more polymer layers in which the polymer composition is different with respect to the thickness direction of the container wall but substantially identical with respect to the plane direction and each of the polymer layers is continuous with respect to the plane direction, in such a manner that a tapered projection protruding outwardly in the thickness direction of the container wall is formed in the joint portion so that each of the polymer layers is substantially continuous in this joint portion. This improved container can easily be prepared according to the customary blow molding technique by using a pair of split molds having such a configuration that a tapered concave groove is formed in the section pinching off the parison when the molds are registered with each other.