# US 4,399,181 A · Cold drawn high-orientation multilayered film and process for manufacture of said film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,181 A - Document ID: US4399181A - Status: Granted - Kind: A - Application number: 06/326,062 - Filed: 1981-11-30 - Granted: 1983-08-16 - Earliest claimed: 1978-12-18 - Assignees: Asahi-Dow Limited - Inventors: Isao Yoshimura; Osamu Mizukami; Hideo Hata; Junichi Kageyama; Takashi Kaneko - Web page: https://patentgrep.com/patent/US4399181A ## CPC - B32B 27/08: of synthetic resin - B29C 55/023: {using multilayered plates or sheets} - B32B 27/304: {comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF} - B32B 27/306: {comprising vinyl acetate or vinyl alcohol (co)polymers} - B32B 27/308: {comprising acrylic (co)polymers} - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - C08J 7/042: {with two or more layers, where at least one layer of a composition contains a polymer binder} - B29K 2023/06: {PE, i.e. polyethylene} - B29K 2023/083: {EVA, i.e. ethylene vinyl acetate copolymer} - B29K 2096/005: {Ionomers} - B32B 2307/514: Oriented - B32B 2307/54: Yield strength; Tensile strength - B32B 2307/736: Shrinkable - B32B 2323/04: Polyethylene - B32B 2323/10: Polypropylene - B32B 2331/04: Polymers of vinyl acetate, e.g. PVA - B32B 2439/00: Containers; Receptacles - B32B 2553/00: Packaging equipment or accessories not otherwise provided for - C08J 2323/06: Polyethene - Y10S 428/91: Product with molecular orientation - Y10T 428/2495: Thickness [relative or absolute] - Y10T 428/26: Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension - Y10T 428/269: including synthetic resin or polymer layer or component - Y10T 428/31725: Of polyamide - Y10T 428/31743: Next to addition polymer from unsaturated monomer[s] - Y10T 428/31746: Polymer of monoethylenically unsaturated hydrocarbon - Y10T 428/31797: Next to addition polymer from unsaturated monomers - Y10T 428/31801: Of wax or waxy material - Y10T 428/31855: Of addition polymer from unsaturated monomers - Y10T 428/31909: Next to second addition polymer from unsaturated monomers - Y10T 428/3192: Next to vinyl or vinylidene chloride polymer - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A high-orientation multilayered film incorporates at least one cold drawn, highly oriented resin layer excellent in mechanical strength and suitable mainly for use as packaging material. Because of its specific stratal construction which is highly adaptable to afford a wide variety of specific functions, the composite film is suitable for manufacture of thermally shrinkable films which excel in transparency and in ability to shrink rapidly particularly at low temperatures. Also disclosed is a process for drawing at specific low temperatures at high expansion ratios the aforementioned multiplicity of resin layers either all by themselves or in conjunction with layers of other resins by utilizing the cold drawability of the aforementioned resin layers excelling in mechanical strength. ## Claims ### Claim 1 A cold drawn high-orientation multilayered film, having a tensile strength of not less than 5.0 g/mm.sup.2, the principal component layers of said film being highly oriented, said multilayer film comprising at least one layer preponderantly comprising a cold-drawable resin selected from the group consisting of blended and unblended specific polymers, [1] (B)+(A)+(C), [2] (B)+(A), [3] (B)+(C), [4] (D), and [5] (E), wherein, (A) is at least one ethylene type polymer selected from the group consisting of copolymers of ethylene with another monomer selected from the group consisting of vinyl esters, aliphatic unsaturated carboxylic acids and alkyl esters of said carboxylic acids, ionically crosslinked resins derived from said copolymers and low-density polymers of ethylene, (B) is a soft copolymer elastomer having a Vicat softening point of not more than 60.degree. C. (C) is at least one polymer selected from the group consisting of crystalline polypropylene, high-density polyethylene, crystalline polybutene-1, and polymethyl pentene-1, (D) is a crystalline polybutene-1 having a concentration of 50 to 100% by weight, and (E) is an ionically crosslinked resin, said multilayered film consisting of at least one cold drawable resin layer (CDR.sub.1-3) preponderantly containing at least one cold drawable resin selected from the group consisting of blended polymers [1], [2], and [3], and at least one cold drawable resin layer (CDR.sub.4) preponderantly containing a polymer [4], and said film having a multilayer construction represented by the layer combination of (I) CDR.sub.1-3 /CDR.sub.4 or CDR.sub.1-3 /CDR.sub.4 /CDR.sub.1-3. ### Claim 2 (depends on 1) The multilayered film according to claim 1, wherein the polymer (A) of the blended specific polymers [1] and [2] is at least one member selected from the group consisting of ethylene-vinylacetate copolymer, ethylene-acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylate copolymer and ethylene-methacrylic acid copolymer. ### Claim 3 (depends on 1, 2) The multlayered film according to claim 1 or 2, wherein the polymer (A) of the blended specific polymers [1] and [2] is an ethylene-vinyl acetate copolymer containing 1 to 13 mol% of vinyl acetate group and having a melt index within the range of from 0.2 to 10. ### Claim 4 (depends on 1) The multilayered film according to claim 1, wherein the polymer (A) of the blended specific polymers [1] and [2] is an ionically crosslinked resin which is a copolymer of ethylene and aliphatic unsaturated carboxylic acid, the carboxyl group of said copolymer being at least partially ionized with metal, and said ionically crosslinked resin is obtained by at least partially saponifying an aliphatic unsaturated alkyl carboxylate and then subjecting the product of saponification to at least partial ionic bonding with metal ### Claim 5 (depends on 1) The multilayered film according to claim 1, wherein the polymer (B) of the blended specific polymers [1], [2] and [3] is a copolymer elastomer containing 90 to 20 mol% of ethylene. ### Claim 6 (depends on 1) The multilayered film according to claim 1, wherein the polymer (B) of the blended specific polymers [1], [2] and [3] is a copolymer elastomer containing 88 to 40 mol% of ethylene. ### Claim 7 (depends on 1) The multilayered film according to claim 1, wherein the polymer (B) of the blended specific polymers [1], [2] and [3] is a soft copolymer comprising ethylene and at least one member selected from the group consisting of .alpha.-olefins of 3 to 12 carbon atoms and possessing a Vicat softening point of not more than 50.degree. C. and a crystallization degree of not more than 30%. ### Claim 8 (depends on 1, 7) The multilayered film according to claim 1 or 7, wherein the copolymer elastomer of the polymer (B) of the blended specific polymers [1], [2] and [3] is a copolymer of ethylene with an .alpha.-olefin and a small amount of a polyene. ### Claim 9 (depends on 8) The multilayered film according to claim 8, wherein the copolymer elastomer is a copolymer containing not more than 5 mol% of a non-conjugated diene selected from the group consisting of polyenes, hexadiene, pentadiene and norbornene derivatives. ### Claim 10 (depends on 7) The multilayered film according to claim 7, wherein the polymer (B) of the blended specific polymers [1], [2] and [3] is a random copolymer whose .alpha.-olefin component is one member selected from the group consisting of propylene and butene-1. ### Claim 11 (depends on 1) The multilayered film according to claim 1, wherein the polymer (C) of the blended specific polymers [1] and [3] is a rigid polymer having a Vicat softening point of not less than 100.degree. C. ### Claim 12 (depends on 1) The multilayered film according to claim 1, wherein the polymer (C) of the blended polymers [1] and [3] is a crystalline polypropylene containing 0 to 7 mol% of ethylene or other .alpha.-olefin as a modifier. ### Claim 13 (depends on 1) The multilayered film according to claim 1, wherein the cold-drawable resin of the specific polymer [1] has a composition such as to satisfy the relations of 0.90.gtoreq.B/(A+B).gtoreq.0.05 and 2.0.gtoreq.C/(A+B).gtoreq.0.05, that of the specific polymer [2] a composition to satisfy the relation of 0.90.gtoreq.B/(A+B).gtoreq.0.05, and that of the specific polymer [3] a composition to satisfy the relation of 0.90.gtoreq.B/(B+C).gtoreq.0.30. ### Claim 14 (depends on 1, 13) The multilayered film according to claim 1 or 13, wherein the cold-drawable resin of the specific polymer [1] has a composition such as to satisfy the relations of 0.70.gtoreq.B/(A+B).gtoreq.0.07 and 1.0.gtoreq.C/(A+B).gtoreq.0.10, that of the specific polymer [2] a composition to satisfy the relation of 0.70.gtoreq.B/(A+B).gtoreq.0.07, and that of the specific polymer [3] a composition to satisfy the relation of 0.87.gtoreq.B/(B+C).gtoreq.0.40. ### Claim 15 (depends on 1) The multilayered film according to claim 1, wherein the film contains at least one layer formed of the polymer [1]. ### Claim 16 (depends on 1) The multilayered film according to claim 1, wherein the specific polymer [4] is included and is a polymer containing not less than 85 mol% of a butene-1 component and having a melt index within the range of from 0.1 to 20. ### Claim 17 (depends on 1) The multilayered film according to claim 1, wherein there is a layer formed of the specific polymer [4] and it contains at least 80% by weight of crystalline polybutene-1. ### Claim 18 (depends on 1) The multilayered film according to claim 1, wherein there is a layer formed predominantly of the specific polymer [5] which contains 50 to 100% by weight of an ionically crosslinked resin which is a copolymer of ethylene and aliphatic unsaturated carboxylic acid, the carboxyl group of said copolymer being at least partially ionized with metal, and said ionically crosslinked resin is obtained by at least partially saponifying an aliphatic unsaturated alkyl carboxylate and then subjecting the product of saponification to at least partial ionic bonding with metal. ### Claim 19 (depends on 1) The multilayered film according to claim 1 wherein there is a layer formed of blended polymers selected from the group consisting of blended specific polymers [1], [2] and [3] which contains at least 50% by weight of the blended polymers. ### Claim 20 (depends on 1) The multilayered film according to claim 1, wherein the layer formed of the cold-drawable resin selected from the group of blended and unblended specific polymers [1] through [5] inclusive has a thickness accounting for at least 20% of the total thickness of the film. ### Claim 21 (depends on 1, 20) The multilayered film according to claim 1 or 20, wherein the layer formed of the cold-drawable resin has a thickness accounting for at least 50% of the total thickness of the film. ### Claim 22 (depends on 1) The multilayered film according to claim 1, wherein there is a cold-drawable resin selected from the group consisting of blended and unblended specific polymers [1], [2], [3] and [5] which is treated with an activated energy ray to an extent such as to contain 0 to 50% by weight of an insoluble gel in boiling xylene and possess a melt index of not more than 0.5. ### Claim 23 (depends on 1) The multilayered film according to claim 1, wherein the component layers of the film excepting the layer containing the cold-drawable resin include at least one layer formed of at least one polymer selected from the group consisting of crystalline polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-aliphatic unsaturated carboxylic acid copolymers and ethylene-aliphatic unsaturated carboxylate copolymers. ### Claim 24 (depends on 1) The multilayered film according to claim 1, wherein the component layers of the film excepting the layer containing the cold-drawable resin includes, as the adhesive layer, at least one layer formed of one member selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-.alpha.-olefin copolymer elastomers, ethylene-aliphatic unsaturated carboxylic acid copolymers and derivatives thereof, and block-copolymerized elastomers of styrene-conjugated diene type monomers. ### Claim 25 (depends on 1) The multilayered film according to claim 1, wherein the layer containing the cold-drawable resin of the specific polymer [4] has deposited on at least one surface thereof a layer formed preponderantly of crystalline polypropylene. ### Claim 26 (depends on 1, 25) The multilayered film according to claim 1 or 25, wherein the film is composed of at least three layers including, as the intermediate layer, the layer containing the cold drawable resin of the specific polymer [4]. ### Claim 27 (depends on 1) The multilayered film according to claim 1, wherein the film is composed of at least three layers including at least one inner layer formed of blended specific polymers selected from [1], [2], and [3] and at least one outer layer formed predominantly of the ionically crosslinked polymer [5]. ### Claim 28 (depends on 1) The multilayered film according to claim 1, wherein the film has a tensile strength of not less than 7 Kg/mm.sup.2 and an elongation of not less than 100%. ### Claim 29 (depends on 1) The multilayered film according to claim 1, wherein the film has a Haze of not more than 4.0%. ### Claim 30 (depends on 1) The multilayered film according to claim 1, wherein the film has a heat shrink tension of not less than 50 gr/mm.sup.2. ### Claim 31 (depends on 1, 30) The multilayered film according to claim 1 or 30, wherein the film has a heat shrink tension of not less than 100 gr/mm.sup.2. ### Claim 32 (depends on 1) The multilayered film according to claim 1, wherein the film has a shrinkage gradient of not more than 2.0. ### Claim 33 (depends on 1) The multilayered film according to claim 1, wherein the temperature at the heat shrinkage of 20% is not more than 85.degree. C.