Styrene butadiene copolymer and polyolefin resins based shrink films
AssigneeGrupo Cydsa, S.A. de C.V.
InventorMario Humberto Gutierrez-Villarreal
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Abstract
This invention is related to the production and application of heat- shrinkable films derived from a mixture of styrene-butadiene copolymer and polyolefin type resins produced by any of the known processes for polymeric films production. Thermal and mechanical properties of the films derived from this invention makes them suitable to be used, among other applications and with no restriction to the field of this invention, in heat-shrinkable labels, safety seals and overwrap type packaging, blister type thermoformed packaging and in general terms for any kind of packaging, overwrap safety packaging such as the employed to pack audiocassettes, videocassettes, books, magazines, etc., to protect them from tampering, as well as in general applications for packaging material.
Claims19
A heat shrinkable thermoplastic film or sheet comprising a block copolymer of styrene-butadiene, wherein the amount of polymerized butadiene units in the copolymer constitutes from about 1 to about 50 weight % of the entire composition, said film or sheet having a tensile strength of about 372 Kg/cm.sup.2 in the machine direction and about 255 Kg/cm.sup.2 in the transversal direction, and a shrinking value at 130.degree. C. of about 44% for the machine direction and about 0% for the transversal direction.
A heat shrinkable thermoplastic film comprising:
- a) an effective amount of a block copolymer of styrene-butadiene;
- wherein the amount of polymerized butadiene units the copolymer constitutes from about 1 to about 50 weight % of the entire composition, said film or sheet having a tensile strength of about 372 Kg/cm.sup.2 in the machine direction and about 255 Kg/cm.sup.2 in the transversal direction, and a shrinking value at 130.degree. C. of about 44% for the machine direction asked about 0% for the transversal direction;
- b) about 0-50% polyethylene;
- and
- c) about 0.01-2% additives.
A heat shrinkable thermoplastic film or sheet comprising a block copolymer of styrene-butadiene, wherein the amount of polymerized butadiene units in the copolymer constitutes from about 1 to about 50 weight % of the entire composition, said film or sheet having a tensile strength between about 335 and about 409 Kg/cm.sup.2 in the machine direction and between about 230 and about 280 Kg/cm.sup.2 in the transversal direction and a shrinking value at 130.degree. C. between about 40% and about 48% for the machine direction and between about 0% to about 10% in the transversal direction.
A heat shrinkable thermoplastic film or sheet comprising a blend of styrene-butadiene copolymer and polyolefin;
- wherein the amount of polymerized butadiene units in the copolymer constitutes from about 1 to about 50 weight % of the entire composition, said film or sheet having a tensile strength between about 335 and about 409 Kg/cm.sup.2 in the machine direction and between about 230 and about 280 Kg/cm.sup.2 in the transversal direction, and having a shrinking value of at 130.degree. C. between about 40% and about 48% for the machine direction and between about 0% to about 10% in the transversal direction.
Dependencies are inferred from the claim text.