EP0053925A2
Expired / Lapsed
EP
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Multi-layered polyolefin laminated film
Assignee: Toray Industries Inc
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Filing: 1981-12-04
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Granted: —
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Expires: 2001-12-04
Abstract
Abstract A three-layered laminated film consisting essentially of (A) a center layer consisting of a crystalline low molecular weight polyolefin having an intrinsic viscosity of 0.5 to 1.4 and (B) two surface layers disposed on both sides of the center layer and each consisting of a crystalline polyolefin (b) having a melting point higher than that of the crystalline low molecular weight polyolefin (a), whereby the thickness of the center layer (A) accounts for 30 to 98 %, especially 50 to 85 %, of the total thickness of the laminated film. The invention also relates to applications of the laminated film. The laminated film of the invention has excellent finger-tearability and high toughness but little tendency to curl, to whiten when torn, to get turbid and fibrillated, and so forth. The laminated film is effectively used as an adhesive tape or other applications.
Inventors
- 👤 Kenji Tsunashima
- 👤 Toshiya Yoshii
- 👤 Takeo Fukuyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 15:21
CPC Classifications
C; C09; C09J; C09J7/00; C09J7/20; C09J7/29; B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B7/00; B32B7/04; B32B7/12; B29; B29K; B29K2995/00; B29K2995/0037; B29K2995/0072; B32B2255/00; B32B2255/10; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/518; B32B2307/538; B32B2307/70; B32B2307/704; B32B2323/00; B32B2323/10; C09J2301/00; C09J2301/10; C09J2301/16; C09J2301/162; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/25; Y10T428/28; Y10T428/2848; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
84 words
A laminated film characterised in that it comprises (A) a centre layer comprising a first crystalline polyolefin, namely a low molecular weight crystalline polyolefin having an intrinsic viscosity of from 0.5 to 1.4, and (B) a surface layer disposed on each side of said centre layer and each comprising a second crystalline polyolefin having a melting point higher than that of said first crystalline polyolefin, the thickness of said centre layer being from 30 to 98% of the total thickness of said laminated film.
Claim 2
Dependent Claim
84 words
A laminated film characterised in that it comprises (A) a centre layer comprising a first crystalline polyolefin, namely a low molecular weight crystalline polyolefin having an intrinsic viscosity of from 0.5 to 1.4, and (B) a surface layer disposed on each side of said centre layer and each comprising a second crystalline polyolefin having a melting point higher than that of said first crystalline polyolefin, the thickness of said centre layer being from 30 to 98% of the total thickness of said laminated film.
Claim 3
Dependent Claim
27 words
A laminated film as claimed in claim 1, wherein the intrinsic viscosity of said first crystalline polyolefin is from 0.7 to 1.2, preferably from 0.8 to 1.1.
Claim 4
Dependent Claim
41 words
A laminated film as claimed in claim 1 or 2, wherein the difference between the melting point of said second crystalline polyolefin and the melting point of said first crystalline polyolefin is from 5 to 50°C, preferably from 10 to 30°C.
Claim 5
Dependent Claim
32 words
A laminated film as claimed in any of claims 1 to 3, wherein the thickness of said centre layer is from 50 to 85% of the total thickness of said laminated film.
Claim 6
Dependent Claim
66 words
A laminated film as claimed in any of claims 1 to 4, .wherein the thickness of said centre layer is from 5 to 90 µm, preferably from 5 to 50 µm, more preferably from 10 to 40 µm, and wherein the thickness of each said surface layer is from 0.5 to 20 µm, preferably from 0.5 to 8 µm, more preferably from 0.5 to 5 µm.
Claim 7
Dependent Claim
27 words
A laminated film as claimed in any of claims 1 to 5, wherein said centre layer is biaxially oriented and said surface layer is also biaxially oriented.
Claim 8
Dependent Claim
64 words
A laminated film as claimed in any of claims 1 to 6, wherein the orientation of said laminated film is such that the difference obtained by reducing birefringence from the absolute value of the difference between the refractive index in the longitudinal direction of the film and the refractive index in the transverse direction is from 0.002 to 0.02, preferably from 0.003 to 0.01.
Claim 9
Dependent Claim
31 words
A laminated film as claimed in any of claims 1 to 7, wherein the intrinsic viscosity of said second crystalline polyolefin is from 0.5 to 2.0, preferably from 0.8 to 1.5.
Claim 10
Dependent Claim
25 words
A laminated film as claimed in any of claims 1 to 8, wherein said first crystalline polyolefin is a propylene copolymer or other olefinic copolymer.
Claim 11
Dependent Claim
22 words
A laminated film as claimed in claim 9, wherein said propylene copolymer contains at least 50 mol % of propylene monomer units.
Claim 12
Dependent Claim
34 words
A laminated film as claimed in claim 9 or 10, wherein said propylene copolymer is a copolymer of propylene and at least one olefin containing from 2 to 10 carbon atoms (other than propylene).
Claim 13
Dependent Claim
23 words
A laminated film as claimed in claim 11, wherein said propylene copolymer is an ethylene-propylene copolymer, a propylene-butene copolymer, or an ethylene-propylene-butene copolymer.
Claim 14
Dependent Claim
20 words
A laminated film as claimed in any of claims 9 to 12, wherein said propylene copolymer is a random copolymer:
Claim 15
Dependent Claim
42 words
A laminated film as claimed in any of claims 1 to 13, wherein said second crystalline polyolefin of at least one of said two surface layers is at least one polymer selected from C 2 - C 10 olefinic homopolymers and copolymers.
Claim 16
Dependent Claim
32 words
A laminated film as claimed in claim 14, wherein said second crystalline polyolefin of at least one of said two surface layers is polypropylene or other C3 7 C 7 olefinic homopolymer.
Claim 17
Dependent Claim
33 words
A laminated film as claimed in any of claims 1 to 15, wherein at least one of the surfaces of said surface layers is rough with surface roughness of 3 to 20 pm.
Claim 18
Dependent Claim
44 words
A laminated film as claimed in claims 15 and 16, wherein said surface layer having said rough surface is polypropylene containing 1 to 25 % by weight, based on said polypropylene, of inorganic particles having a particle size of from 0.1 to 10 fm.
Claim 19
Dependent Claim
47 words
A laminated film as claimed in claims 14 and 16, wherein said surface layer having said rough surface is an ethylene-propylene block copolymer containing 1 to 25 % by weight, based on said copolymer, of inorganic particles having a particle size of from 0.1 to 10 µm.
Claim 20
Dependent Claim
43 words
A laminated film as claimed in any of claims 1 to 18, wherein.said centre layer comprises a blend of said first crystalline polyolefin and from 5 to 40 % by weight, preferably from 10 to 30% by weight, of said second crystalline polyolefin.
Claim 21
Dependent Claim
33 words
A laminated film as claimed in any of claims 1 to 19, wherein the Sharpy impact value of said laminated film is up to 5 kg - cm/cm, preferably up to 3 kg-cm/cm.
Claim 22
Dependent Claim
46 words
A laminated film as claimed in any of claims 1 to 20, wherein at least one of said first crystalline polyolefin and said second crystalline polyolefin contains from 0.001 to 0.5 % by weight, preferably from 0.05 to 0.3 % by weight of a nucleating agent.
Claim 23
Dependent Claim
32 words
A laminated film as claimed in any of claims 1 to 21, wherein at least one surface of said laminated film is coated with an adhesive agent to form an adhesive tape.
References Cited (Backward Citations)
No citation records indexed.
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