# US 4,393,115 A · Multilayered polypropylene film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,393,115 A - Document ID: US4393115A - Status: Granted - Kind: A - Application number: 06/283,380 - Filed: 1981-07-15 - Granted: 1983-07-12 - Earliest claimed: 1980-07-22 - Assignees: Toray Industries, Inc. - Inventors: Toshiya Yoshii; Satoru Nakura; Masatsugi Murakami - Web page: https://patentgrep.com/patent/US4393115A ## CPC - B32B 27/08: of synthetic resin - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - B32B 2307/514: Oriented - B32B 2307/516: mono-axially - B32B 2307/518: bi-axially - B32B 2323/10: Polypropylene - B32B 2405/00: Adhesive articles, e.g. adhesive tapes - Y10S 428/91: Product with molecular orientation - Y10T 428/24967: Absolute thicknesses specified - Y10T 428/24975: No layer or component greater than 5 mils thick - Y10T 428/25: Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles - Y10T 428/252: Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.] - Y10T 428/256: Heavy metal or aluminum or compound thereof - Y10T 428/257: Iron oxide or aluminum oxide - Y10T 428/258: Alkali metal or alkaline earth metal or compound thereof - Y10T 428/259: Silicic material - Y10T 428/26: Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension - Y10T 428/265: 1 mil or less - Y10T 428/28: Web or sheet containing structurally defined element or component and having an adhesive outermost layer - Y10T 428/2826: Synthetic resin or polymer - Y10T 428/2848: Three or more layers - Y10T 428/31909: Next to second addition polymer from unsaturated monomers - Y10T 428/31913: Monoolefin polymer - Y10T 428/31938: Polymer of monoethylenically unsaturated hydrocarbon - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Laminating a stretched thin propylene-ethylene block copolymer layer onto a surface of a laminate film hving a biaxially oriented polypropylene layer and a polypropylene layer uniaxially oriented only in the width direction. The resulting film has improved hand-cutting properties and the surface accepts wiring or drawing and is especially advantageous for use as adhesive tape. ## Claims ### Claim 1 A multilayered polypropylene film capable of being readily cut by hand and having a surface which is capable of accepting writing or drawing thereon, which comprises a biaxially oriented polypropylene layer and a polypropylene layer uniaxially oriented in the direction of its width, and laminated upon at least one surface of said laminated film a propylene-ethylene block copolymer layer stretched uniaxially or biaxially. ### Claim 2 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein the thickness of said polypropylene layer uniaxially oriented in the direction of width is in the range between about 1.2 and 5.0 times the thickness of said biaxially oriented polypropylene layer, and wherein the thickness of said block copolymer layer is in the range between about 0.5 and 8.0 .mu.m, and wherein the total thickness of said multilayered polypropylene film is in the range between about 15 and 60 .mu.m. ### Claim 3 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said propylene-ethylene block copolymer layer contains inorganic fine particles in an amount of about 5 to 40% by weight on the basis of the weight of said copolymer. ### Claim 4 (depends on 3) A multilayered polypropylene film as claimed in claim 3, wherein said percentage is about 10-30%. ### Claim 5 (depends on 3) A multilayered polypropylene film as claimed in claim 3, wherein said fine particles have sizes of about 0.1 to 10 .mu.m. ### Claim 6 (depends on 5) A multilayered polypropylene film as claimed in claim 5, wherein said fine particles have sizes of about 0.5 to 5 .mu.m. ### Claim 7 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said propylene-ethylene block copolymer has an ethylene content in the range of about 5 to 40% on the basis of the weight of said copolymer. ### Claim 8 (depends on 7) A multilayered polypropylene film as claimed in claim 7, wherein said ethylene content is about 10 to 30%. ### Claim 9 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said propylene-ethylene block copolymer layer further contains polyethylene in the range of about 1 to 30% on the basis of the weight of said copolymer. ### Claim 10 (depends on 9) A multilayered polypropylene film as claimed in claim 9, wherein the content of said polyethylene is about 2-20%. ### Claim 11 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said propylene-ethylene block copolymer contains organic peroxide in an amount of about 0.001 to 1.0% on the basis of the weight of said copolymer. ### Claim 12 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein the block copolymer has a ratio of absorbence at 720 cm.sup.-1 to absorbence at 731 cm.sup.-1 of about 0.4 to 3.0. ### Claim 13 (depends on 12) A multilayered polypropylene film as claimed in claim 12, wherein said ratio is about 0.6 to 2.0. ### Claim 14 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said stretching is uniaxial and the stretch ratio is about 3-12. ### Claim 15 (depends on 14) A multilayered polypropylene film as claimed in claim 14, wherein said stretch ratio is about 5-10. ### Claim 16 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein said stretching is biaxial and the stretch ratio is about 35-70 expressed as an area ratio. ### Claim 17 (depends on 16) A multilayered polypropylene film as claimed in claim 16, wherein said ratio is about 40-60. ### Claim 18 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein the biaxially oriented polypropylene layer has a refraction index at 589 m.mu. above 1.501 in both the longitudinal and transverse directions of the film. ### Claim 19 (depends on 18) A multilayered polypropylene film as claimed in claim 18, wherein said index is above 1.505. ### Claim 20 (depends on 1) A multilayered polypropylene film as claimed in claim 1, wherein the uniaxially oriented polypropylene layer has a refraction index measured at a wavelength of 589 m.mu. smaller than 1.505 in the longitudinal direction and larger than 1.510 in the transverse direction.