Resinous compositions having improved processability and gas permeation resistance and molded structures thereof

Claim 2

A MOLDED STRUCTURE HAVING AN IMPROVED GAS PERMEATION RESISTANCE, SAID MOLDED STRUCTURE HAVING BEEN FORMED BY MEANS OF EXTRUSION MOLDING FROM A MOLTEN MIXTURE CONTAINING (A) A POLYOLEFIN AND (B) A SAPONIFIED PRODUCT OF AN ETHYLENEVINYL ACETATE COPOLYMER HAVING AN ETHYLENE CONTENT OF 25 TO 50 MOLE PERCENT AND A DEGREE OF SAPONIFICATION OF AT LEAST 96% AT A WEIGHT RATIO OF A : B RANGING FROM 95 : 5 TO 75 : 25, AND (C) 0.5 TO 15 PARTS BY WEIGHT, PER 100 PARTS BY WEIGHT OF THE SUM OF SAID POLYEFIN AND SAID ETHYLENE-VINYL ACETATE COPOLYMER SAPONIFIED PRODUCT, OF A THERMOPOLASTIC POLYMER CONTAINING A CARBONYL GROUP IN THE MAIN OR SIDE CHAIN THEREOF, SAID MOLDED STRUCTURE HAVING A LAYER STRUCTURE IN WHICH THE POLYMER COMPOSITION IS DIFFERENT IN THE THICKNESS DIRECTION BUT SUBSTANTIALLY IDENTICAL IN THE PLANE DIRECTION AND EVERY TWO ADJACENT LAYERS ARE BONDED TO EACH OTHER WITHOUT ANY INTERMEDIATE BONDING LAYER OF AN ADHESIVE, SAID LAYER STRUCTURE CONSISTING ESSENTIALLY OF (A) AT LEAST ONE LAYER IN WHICH THE SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMER IS PREDOMINANTLY DISTRIBUTED, (B) AT LEAST ONE LAYER IN WHICH THE POLYOLEFIN IS PREDOMINANTLY DISTRIBUTED, AND (C) AT LEAST ONE LAYER WHICH COMPRISES THE SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMER AND THE POLYOLEFIN IN AMOUNTS SUBSTANTIALLY SAME AS THE AVERAGE CONTENTS OF THE SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMER AND THE POLYOLEFIN IN SAID LAYER STRUCTURE, SAID LAYER (C)INTERVENING BETWEEN SAID LAYER (A) AND LAYER (B) TO BOND THEM INTEGRALLY, THE SAID CARBONYL GROUP-CONTAINING THERMOPLASTIC POLYMER BEING DISTRIBUTED THROUGHOUT THE SAID LAYER STRUCTURE, AND WHEREIN WHEN SAID MOLED STRUCTURE IS DIVIDED IN THREE LAYER IN THE THICKNESS DIRECTION, AT LEAST ONE LAYER (A) CONTAINS THE ETHYLENE-VINYL ACETATE COPOLYMER SAPONIFIED PRODUCT IN AN AMOUNT EXPRESSED BY FOLLOWING FORMULA M1 = M1 X WHEREIN X IS THE AVERAGE CONTENT (PERCENT BY WEIGHT) OF THE ETHYLENE-VINYL ACETATE COPOLYMER SAPONIFIED PRODUCT IN SAID MOLDED STRUCTURE, M1 IS A NUMBER OF FROM 1.2 TO 4, AND M1 IS THE CONTENT (PERCENT BY WEIGHT) OF THE ETHYLENEVINYL ACETATE COPOLYMER SAPONIFIED PRODUCT IN SAID LAYER, AND AT LEAST ONE LAYER (B) CONTAINS THE ETHYLENE-VINYL ACETATE COPOLYMER SAPONIFIED PRODUCT IN AN AMOUNT EXPRESSED BY THE FOLLOWING FORMULA M2 - M2X WHEREIN X IS AS DEFINED ABOVE, M2 IS A NUMBER OF FROM 0 TO 0.9, AND M2 IS THE CONTENT (PERCENT BY WEIGHT) OF THE ETHYLENE-VINYL ACETATE COPOLYMER SAPONIFIED PRODUCT IN SAID LAYER.

Claim 3

A molded structure according to claim 1 wherein when said molded structure is divided in three layers in the thickness direction, a first surface layer is said layer (a), and a second layer is said layer (b) and an intermediate layer is said layer (c).

Claim 4

A molded structure according to claim 1 wherein when Said molded structure is divided in three layers in the thickness direction, two surface layers comprise said layer (a) and an intermediate layer comprises said layer (b).

Claim 5

A molded structure according to claim 1 wherein when said molded structure is divided in three layers in the thickness direction, two surface layers comprise said layer (b) and an intermediate layer comprises said layer (a).

Claim 6

A molded structure is set forth in claim 1, wherein the thermoplastic polymer (C) is a member selected from the group consisting of polymers composed of a monomer expressed by the following formula

Claim 7

A molded structure as set forth in claim 1, wherein the thermoplastic polymer (C) is a member selected from the group consisting of polymers composed of a monomer expressed by the following formula

Claim 8

A molded structure as set forth in claim 1, wherein the thermoplastic polymer (C) is an ionomer.

Claim 9

A molded structure as set forth in claim 1, wherein the thermoplastic polymer (C) is a copolymer of maleic anhydride with other Alpha , Beta -ethylenically unsaturated monomer free of a carbonyl group.

Claim 10

A molded structure as set forth in claim 1, wherein the thermoplastic polymer (C) is a polyamide or interpolyamide consisting of the recurring units expressed by the formula

Claim 11

A molded structure set forth in claim 1, wherein the polyolefin is a crystalline homopolymer or copolymer of an olefin expressed by the following formula

Claim 12

A molded structure set forth in claim 1, wherein the polyolefin is a low density polyethylene having a density of from 0.917 to 0.929 g/cc.

Claim 13

A molded structure set forth in claim 1, wherein the polyolefin is a medium density polyethylene having a density of from 0.930 to 0.939 g/cc.

Claim 14

A molded structure set forth in claim 1, wherein the polyolefin is a high density polyethylene having a density of at least 0.940 g/cc.

Claim 15

A molded structure set forth in claim 1, wherein the polyolefin is an isotactic polypropylene.

Claim 16

A molded structure set forth in claim 1, wherein the saponified ethylene-vinyl acetate copolymer has an intrinsic viscosity ( eta ), measured at 30*C. with use of a mixed solvent of 85 % by weight of phenol and 15 % by weight of water, of from 0.07 to 0.17 l/g.

Claim 17

A molded structure set forth in claim 1, wherein the thermoplastic polymer (C) contains carbonyl groups in an amount of from 120 to 1400 milliequivalents per 100 g of the polymer.

Claim 18

A molded structure set forth in claim 1, which is in the form of a container.

Claim 19

A molded structure set forth in claim 1, which is in the form of a film.

Claim 20

A molded structure set forth in claim 1, which is in the form of a tube.

Claim 21

A molded structure, said molded structure having been formed by means of extrusion molding from a molten mixture containing (A) a polyolefin and (B) a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 25 to 50 mole percent and a degree of saponification of at least 96% at a weight ratio of A : B ranging from 95 : 5 to 75 : 25, and (C) 0.5 to 15 parts by weight, per 100 parts by weight of the sum of said polyolefin and said ethylene-vinyl acetate copolymer saponified product, of a thermoplastic polymer containing a carbonyl group in the main or side chain thereof, under such condition that the difference between the average flow rate of the polyolefin melt and the average flow rate of the melt of the saponified ethylene-vinyl acetate copolymer is at least 1 cm/sec and the molten mixture moves through the extrusion apparatus in the form of a laminar flow, said molded structure having a layer structure in which the polymer composition is different in the thickness direction but substantially identical in the plane direction, said layer structure consisting essentially of (a) at least one layer in which the saponified ethylene-vinyl acetate copolymer is predominantly distributed, (b) at least one layer in which the polyolefin is predominantly distributed, and (c) at least one layer which comprises a mixture of saponified ethylene-vinyl acetate copolymer and the polyolefin in an approximately same amount as the average content, said layer (c) intervening between said layer (a) and layer (b) to bond them integrally, the said carbonyl group-containing thermoplastic polymer being distributed throughout the layer structure, and wherein when said molded structure is divided in three layers in the thickness direction, at least one layer (a) contains the ethylene-vinyl acetate copolymer saponified product in an amount expressed by following formula M1 m1X wherein X is the average content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said molded structure, m1 is a number of from 1.2 to 4, and M1 is the content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said layer. and at least one layer (b) contains the ethylene-vinyl acetate copolymer saponified product in an amount expressed by the following formula M2 - m2X wherein X is as defined above, m2 is a number of from 0 to 0.9, and M2 is the content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said layer.

Claim 22

A molded structure, said molded structure having been formed by means of extrusion molding from a molten mixture containing (A) a polyolefin and (B) a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 25 to 50 mole percent and a degree of saponification of at least 96% at a weight ratio of A : B ranging from 95 : 5 to 75 : 25, and (C) 0.5 to 15 parts by weight, per 100 parts by weight of the sum of said polyolefin and said ethylene-vinyl acetate copolymer saponified product, of a thermoplastic polymer containing a carbonyl group in the main or side chain thereof, under such condition that the difference between the average flow rate of the polyolefin melt and the average flow rate of the melt of the saponified ethylene-vinyl acetate copolymer is at least 1 cm/sec and the molten mixture moves through the extrusion apparatus in the form of a laminar flow, said molded structure having a layer structure in which the polymer composition is different in the thickness direction but substantially identical in the plane direction, said layer structure consisting essentially of (a) at least one layer in which the saponified ethylene-vinyl acetate copolymer is predominantly distributed, (b) at least one layer in which the polyolefin is predominantly distributed, and (c) at least one layer which comprises a mixture of saponified ethylene-vinyl acetate copolymer and the polyolefin in an approximately same amount as the average content, said layer (c) intervening between said layer (a) and layer (b) to bond them integrally, the said carbonyl group-containing thermoplastic polymer being distributed throughout the layer structure, and wherein when said molded structure is divided in three layers in the thickness direction, at least one layer (a) contains the ethylene-vinyl acetate copolymer saponified product in an amount expressed by following formula M1 m1X wherein X is the average content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said molded structure, m1 is a number of from 1.2 to 4, and M1 is the content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said layer. and at least one layer (b) contains the ethylene-vinyl acetate copolymer saponified product in an amount expressed by the following formula M2 - m2X wherein X is as defined above, m2 is a number of from 0 to 0.9, and M2 is the content (percent by weight) of the ethylene-vinyl acetate copolymer saponified product in said layer.