TH45898A - Laminated packaging material Improved And related production methods - Google Patents

Abstract

DC60 (03/08/43) Laminated packaging material in the form of sheets, strips or mesh for the manufacture of rigid, leak-proof packaging by folding, thermoforming or other mechanical processes for shaping the material. The material consists of extruded first and second layers; the first layer consists of a type 1 thermoplastic material chosen from a polymer group consisting primarily of propylene, preferably propylene homopolymers or copolymers derived from propylene and ethylene, and includes 5% to 85% by weight of inorganic mineral fillers, preferably dolomite and talc. The second layer consists of a type 2 thermoplastic material chosen from a polymer group consisting primarily of ethylene, preferably low-density polyethylene (LDPE). Under this invention, the first and second layers are laminated directly onto each other and no adhesive is required. In this invention, laminated packaging materials, in the form of sheets, strips, or mesh, are used to produce rigid, leak-proof packaging by folding, thermoforming, or other mechanical processes for shaping the material. The material consists of two extruded layers: a first and a second layer; the first layer includes a type I thermoplastic material chosen from a polymer group primarily composed of propylene, preferably propylene homopolymers or copolymers derived from propylene and ethylene, and includes 5% to 85% by weight of inorganic mineral fillers, preferably dolomite and talc. The second layer includes a type II thermoplastic material chosen from a polymer group primarily composed of ethylene, preferably low-density polyethylene (LDPE). Under this invention, the first and second layers are laminated directly onto each other without the need for any adhesive in between.

Claims (21)

1. Laminated packaging materials in the form of sheets, strips or meshes used to produce rigid, leak-proof packaging by folding and sealing, heat forming or other mechanical processes for shaping the material; which materials consist of at least one such first layer (3) and a second layer (4); the first layer (3) consists of a thermoplastic material of type one selected from the group consisting mainly of propene resins; and the second layer (4) consists of a thermoplastic material of type two selected from the group consisting mainly of polyethene resins; which is notable in that the aforementioned first layer (3) and second layer (4) are laminated directly onto each other and the first layer (3) contains 5% to 85% by weight of inorganic mineral filler. 2. Laminated packaging material, according to claim 1, which has the special characteristics that the first layer (3) is composed of 50% to 85% inorganic mineral filler by weight. 3. Laminated packaging materials as per claim 1 or 2, with the following characteristics: 1. Inorganic mineral filler consisting of at least one substance selected from a group comprising dolomite, track, chalk, mica, calcium carbonate. 4. Laminated packaging materials, as per claim 3, which are characterized by the inorganic mineral filler consisting of a mixture of dolomite and talc. 5. Laminated packaging materials, as per claim 4, are characterized by the total content of dolomite in the inorganic mineral filler being between 75% and 90% by weight, and the content of tac being between 10% and 25% by weight. 6. Laminated packaging materials, as per any one of claims 1 through 5, which are characterized by the first layer still containing a compatibility substance in an amount less than 1% by weight. 7. Laminated packaging materials, as per claim 6, which is characterized by the second thermoplastic material being low-density polyethylene. 8. Laminated packaging materials, as per one of the claims above, which are characterized by the fact that the thermoplastic material of type I is a polyethylene resin. 9. Laminated packaging materials, as per any one of claims 1 through 7, which are characterized by the fact that the first type of thermoplastic material is a copolymer of propylene and ethylene. 10. Laminated packaging materials under any of the above claims that have the special characteristic that the first layer (3) shall have a thickness between 90 and 150 μm. 11. Laminated packaging materials according to any one of the above claims which have the special characteristic that the second layer (4) shall have a thickness between 10 and 25 μm. 12. Laminated packaging materials, according to one of the above claims, which have the special characteristic that they are also composed of a divider (5). 13. Laminated packaging materials, according to the claim in clause 12, which has special characteristics, the divider (5) is a thin aluminum sheet. 14. Laminated packaging materials according to claims in clauses 12 or 13 that have the special characteristics of such partitions (5) have a thickness between 5 and 10 μm. 15. Laminated packaging materials under any of the claims 11 to 14 that have the special characteristic that in fact they also consist of a third layer (6). 16. Laminated packaging material, according to claim 15, which is characterized as a third layer (6) composed of polyethylene homopolymer. 17. Laminated packaging material according to claim 15 or 16 which is of a special nature in that it actually still consists of a fourth layer (7). 18. Laminated packaging material, according to claim 17, which has the following characteristics: 1. The fourth layer sheet (7) consists of a material selected from a group consisting of polyethylene resin and polymer adhesive. 19. A laminated packaging material under any of the above claims which is of the special characteristic that it still consists of an outer layer (2) which is laminated directly onto the first layer (3) and which is made of polyethylene homopolymer. 20. Methods for producing laminated packaging materials in the form of sheets, strips, and meshes for use in rigid, leak-proof packaging by folding, thermoforming, or other mechanical processes for shaping the material: Such methods consist of the following steps: - Forming a first layer of a thermoplastic material of type I, selected from groups consisting primarily of polypropylene polymers. - Forming a second layer of thermoplastic material of type II, selected from groups consisting primarily of ethylene homopolymers; notably, the first and second layers are laminated directly onto each other; and the first layer contains 5% to 85% inorganic mineral fillers by weight. 21. Laminated material as per claim 18, with such polymerization being an ethylene-acid copolymer.