Polymers having improved processability
First Claim
Patent Images
1. A process for film-blowing a poly(lactone), comprising:
- (a) providing a poly(lactone) having non-linear polymer chains, said poly(lactone) being formed by reaction between a lactone monomer and an initiator system comprising at least one polyfunctional initiator having at least three active hydrogens, the amount of said initiator being such that the theoretical molecular weight, per active hydrogen, of the poly(lactone) polymer chains formed by reaction with said initiator is at least 25,000, having a melting temperature of greater than 45°
C., having a shear viscosity, when measured at some temperature in the range of from 35 to 45°
C. above the melting temperature of the poly(lactone), of at least 6 kPas at 0.1 s−
1 shear rate and not greater than 3.5 kPas at 100 s−
1 shear rate, and having a shear viscosity activation energy of greater than 40 kJ/mol;
(b) extruding said poly(lactone) through an annular die to form a tube of molten polymer;
(c) inflating said tube to produce a bubble; and
(d) cooling the bubble or allowing the bubble to cool to solidify the polymer.
2 Assignments
0 Petitions
Accused Products
Abstract
Poly(lactones) are provided. The poly(lactones) are obtained by polymerization of a lactone with an initiator system comprising at least one polyfunctional initiator. The poly(lactones) have a shear viscosity at some temperature in the range of from 35 to 45° C. above the melting temperature of the poly(lactone) of at least 6 kPas at 0.1 s−1 shear rate and no greater than 3.5 kPas at 100 s−1 shear rate, and a shear viscosity activation energy of greater than 40 kJ/mol. Preferably, the poly(lactone) is poly(caprolactone).
-
Citations
32 Claims
-
1. A process for film-blowing a poly(lactone), comprising:
-
(a) providing a poly(lactone) having non-linear polymer chains, said poly(lactone) being formed by reaction between a lactone monomer and an initiator system comprising at least one polyfunctional initiator having at least three active hydrogens, the amount of said initiator being such that the theoretical molecular weight, per active hydrogen, of the poly(lactone) polymer chains formed by reaction with said initiator is at least 25,000, having a melting temperature of greater than 45°
C., having a shear viscosity, when measured at some temperature in the range of from 35 to 45°
C. above the melting temperature of the poly(lactone), of at least 6 kPas at 0.1 s−
1 shear rate and not greater than 3.5 kPas at 100 s−
1 shear rate, and having a shear viscosity activation energy of greater than 40 kJ/mol;
(b) extruding said poly(lactone) through an annular die to form a tube of molten polymer;
(c) inflating said tube to produce a bubble; and
(d) cooling the bubble or allowing the bubble to cool to solidify the polymer. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 29, 31)
(a) a poly(caprolactone) having a molecular weight of from 500 to 2000 and which has itself been initiated by trimethylolpropane or pentaerythritol, and (b) cetyl alcohol and butane-1,4-diol, said poly(caprolactone) having a shear viscosity at 100°
C. from 10 kPas to 20 kPas at 0.1 s−
1 shear rate and from 1 kPas to 2 kPas at 100 s−
1 shear rate.
-
-
2. A polymerization process for the production of a poly(lactone) having non-linear polymer chains which comprises:
-
(a) reacting a lactone monomer with an initiator system, said initiator system comprising at least one polyfunctional initiator having at least three active hydrogens, the amount of said initiator system being such that the theoretical molecular weight, per active hydrogen, of the poly(lactone) polymer chains formed by reaction with said initiator is at least 25,000, said reaction being carried out under an air or inert atmosphere in the presence of a catalyst; and
continuing the reaction until the reaction is substantially complete and until the poly(lactone) produced has a melting temperature of greater than 45°
C., a shear viscosity when measured at some temperature in the range of 35 to 45°
C. above the melting temperature of the poly(lactone) of at least 6 kPas at 0.1 s−
1 shear rate and not greater than 3.5 kPas at 100 s−
1 shear rate, and a shear viscosity activation energy of greater than 40 kJ/mol.- View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 32)
(a) a poly(caprolactone) having a molecular weight of from 500 to 2000 and which has itself been initiated by trimethylolpropane or pentaerythritol, and (b) cetyl alcohol and butane-1,4-diol, said poly(caprolactone) having a shear viscosity at 100°
C. from 10 kPas to 20 kPas at 0.1 s−
1 shear rate and from 1 kPas to 2 kPas at 100 s−
1 shear rate.
-
Specification