Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
231 words
A process for the production of a composite, biaxially oriented, thermoplastic hollow shaped article, comprising externally barrier covering a thermoplastic tubular blank, parison or preform with a relatively thick barrier layer consisting essentially of water and water-resistant and highly crystalline polyvinyl alcohol, said barrier layer having been prepared by (a) introducing into an extruder flakes or granules of a mixture of polyvinyl alcohol and water having a water content ranging from 25 to 35% by weight of said mixture said flakes or granules of polyvinyl alcohol having an ester number less than 20; (b) fluxing and melting the flakes or granules at a temperature at least 100° C. above the equilibrium melting point of said mixture such as to avoid any phase heterogeneity in the molten mass; and (c) forming a barrier covering of said molten mass of flakes having said water content of from 25 to 35% by weight on a substrate of said thermoplastic tubular blank, parison or perform while maintaining the temperature of said molten mass, if necessary by cooling, at a value which is below the temperature at which the vapor pressure of the water in the mixture would cause surface expansion and bubbling of the barrier layer but above or equal to the equilibrium melting point of said mixture; and biaxially orienting and blow molding the barrier covered substrate of step (c) into a final configuration.
Claim 2
Dependent Claim
231 words
A process for the production of a composite, biaxially oriented, thermoplastic hollow shaped article, comprising externally barrier covering a thermoplastic tubular blank, parison or preform with a relatively thick barrier layer consisting essentially of water and water-resistant and highly crystalline polyvinyl alcohol, said barrier layer having been prepared by (a) introducing into an extruder flakes or granules of a mixture of polyvinyl alcohol and water having a water content ranging from 25 to 35% by weight of said mixture said flakes or granules of polyvinyl alcohol having an ester number less than 20; (b) fluxing and melting the flakes or granules at a temperature at least 100° C. above the equilibrium melting point of said mixture such as to avoid any phase heterogeneity in the molten mass; and (c) forming a barrier covering of said molten mass of flakes having said water content of from 25 to 35% by weight on a substrate of said thermoplastic tubular blank, parison or perform while maintaining the temperature of said molten mass, if necessary by cooling, at a value which is below the temperature at which the vapor pressure of the water in the mixture would cause surface expansion and bubbling of the barrier layer but above or equal to the equilibrium melting point of said mixture; and biaxially orienting and blow molding the barrier covered substrate of step (c) into a final configuration.
Claim 3
Dependent Claim
27 words
The process as defined by claim 1, said barrier covering and shaping being carried out by (c-1) extruding the molten mass about said blank, parison or preform.
Claim 4
Dependent Claim
14 words
The process as defined by claim 2, said extrusion being through a coating die.
Claim 5
Dependent Claim
17 words
The process as defined by claim 3, which further comprises cooling the molten mass prior to extrusion.
Claim 6
Dependent Claim
36 words
The process as defined by claim 1, said barrier covering being carried out by (c-2) extruding/blow molding a tube of said molten mass, and (c-4) applying same as a sleeve about said blank, parison or preform.
Claim 7
Dependent Claim
40 words
The process as defined by claim 1, said barrier covering being carried out by (c-3) extruding a tube of said molten mass, under slight internal air pressure, and (c-4) applying same as a sleeve about said blank, parison or preform.
Claim 8
Dependent Claim
46 words
The process as defined by claim 1, said polyvinyl alcohol having a degree of syndiotacticity of more than 50% by weight, an ash content of less than 1.5% by weight and a proportion of 1,2-glycol linkages of less than 1.5 such linkages per 100 monomer units.
Claim 9
Dependent Claim
22 words
The process as defined by claim 7, the water content of said polyvinyl alcohol flakes or granules being about 30% by weight.
Claim 10
Dependent Claim
28 words
The process as defined by claim 1, wherein the temperature of the molten mass being shaped into said barrier covering in step (c) is less than 105° C.
Claim 11
Dependent Claim
33 words
The process as defined by claim 9 wherein the temperature of the molten mass being shaped is between the equilibrium melting point of the admixture of polyvinyl alcohol and water and 98° C.
Claim 12
Dependent Claim
36 words
The process as defined by claim 4 wherein the cooling of the molten extrudate, is carried out before the molten extrudate passes through the die, by means of a cooler-homogenizer introduced upstream of the coating die.
Claim 13
Dependent Claim
21 words
The process as defined by claim 2 wherein the molten mass is extruded through a coating die about a thermoplastic tube.
Claim 14
Dependent Claim
18 words
The process as defined by claim 5 wherein a polyvinyl alcohol sleeve is applied to a thermoplastic preform.
Claim 15
Dependent Claim
18 words
The process as defined by claim 6 wherein a polyvinyl alcohol sleeve is applied to a thermoplastic preform.
Claim 16
Dependent Claim
21 words
The process as defined by claim 1 wherein the thermoplastic constituting said blank, parison or preform is a poly-(alkylene glycol) terephthalate.
Claim 17
Dependent Claim
23 words
The process as defined by claim 1, the thickness of the barrier coating on the product shaped article ranging from 10 to 200μ.
Claim 18
Dependent Claim
36 words
The process as defined by claim 1 wherein the step (b) of fluxing and melting the flakes or granules is carried out at a temperature in the range of from about 150° C. to 220° C.
Claim 19
Dependent Claim
32 words
The process as defined by claim 17 which further comprises cooling the molten mass formed in step (b) to a temperature of less than 105° C. prior to forming the barrier covering.
Claim 20
Dependent Claim
36 words
The process as defined by claim 17 which further comprises cooling the molten mass from step (b) to a temperature between the equilibrium melting point of the admixture of polyvinyl alcohol and water an 98° C.