US5326627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyolefin-based wrapping film
Assignee: Mitsubishi Chemical Corp
•
Filing: 1992-10-20
•
Granted: 1994-07-05
•
Expires: 2012-10-20
Abstract
Abstract A polyolefin-based wrapping film having one or more layers which satisfies the following conditions (1) to (4): (1) the film has a thickness ranging from 6 to 100 mu m; (2) the film has a birefringence DELTA nA of from 0.6x10-3 to 8x10-3; (3) the film has a ratio of percent heat shrinkage in MD to percent heat shrinkage in TD of from 0.65 to 1.50 in a silicon oil bath at 140 DEG C. for 3 minutes; and (4) the film has a strain recovery of at least 18 mm, which provides excellent performance properties in stretch wrapping, especially in the area of high deformation recover.
Inventors
- 👤 Takao Yazaki
- 👤 Masataka Noro
- 👤 Takashi Matsui
- 👤 Noriyuki Kobayashi
- 👤 Hironari Sano
- 👤 Koji Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:33
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29D; B29D7/00; B29D7/01; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/25; B29C48/88; B29C48/885; B29C48/91; B29C48/911; B29C48/9115; B29C48/912; B32B1/00; B32B1/08; B32B27/18; B32B27/32; C; C08; C08J; C08J5/00; C08J5/18; B32B2307/00; B32B2307/70; B32B2307/718; B32B2309/00; B32B2309/08; B32B2309/10; B32B2309/105; C08J2323/00; C08J2323/02; C08J2323/04; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149; Y10T428/25; Y10T428/259; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31801; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
170 words
A wrapping film of a polyolefin-based resin, wherein the film has the following properties: (1) a thickness ranging from 6 to 100 μm; (2) a birefringence Δn A ranging from 0.6×10 -3 to 8×10 -3 , said birefringence defined by equation: Δn.sub.A =|n.sub.MD -n.sub.TD | wherein n MD is a refractive index in the machine direction, and n TD is a refractive index in the transverse direction; (3) a ratio S MD /S TD ranging from 0.65 to 1.50, wherein S MD and S TD are each heat shrinkage in the machine direction and that in the transverse direction when the film is allowed to stand in a silicone oil bath at 140° C. for 3 minutes; and (4) a strain recovery of 18 mm or more, as determined by clamping a circular film specimen having a diameter of 100 mm, indenting at the center thereof with a hemispherical indenter 20 mm in diameter to cause deformation, and measuring the maximum strain which disappears completely upon removal of the indenter.
Claim 2
Dependent Claim
170 words
A wrapping film of a polyolefin-based resin, wherein the film has the following properties: (1) a thickness ranging from 6 to 100 μm; (2) a birefringence Δn A ranging from 0.6×10 -3 to 8×10 -3 , said birefringence defined by equation: Δn.sub.A =|n.sub.MD -n.sub.TD | wherein n MD is a refractive index in the machine direction, and n TD is a refractive index in the transverse direction; (3) a ratio S MD /S TD ranging from 0.65 to 1.50, wherein S MD and S TD are each heat shrinkage in the machine direction and that in the transverse direction when the film is allowed to stand in a silicone oil bath at 140° C. for 3 minutes; and (4) a strain recovery of 18 mm or more, as determined by clamping a circular film specimen having a diameter of 100 mm, indenting at the center thereof with a hemispherical indenter 20 mm in diameter to cause deformation, and measuring the maximum strain which disappears completely upon removal of the indenter.
Claim 3
Dependent Claim
27 words
A wrapping film as claimed in claim 1, wherein film has a tensile modulus of from 600 to 1400 kg/cm 2 in both machine and transverse directions.
Claim 4
Dependent Claim
43 words
A wrapping film as claimed in claim 1, wherein said film has a ratio of stress at 50% elongation in the machine direction (T MD ) to stress at 50% elongation in the transverse direction (T TD ) of from 0.50 to 2.50.
Claim 5
Dependent Claim
41 words
A wrapping film as claimed in claim 1, wherein said film has a ratio of percent heat shrinkage in the machine direction (S MD ) to percent heat shrinkage in the transverse direction (S TD ) of from 0.7 to 1.35.
Claim 6
Dependent Claim
120 words
A wrapping film as claimed in claim 1, wherein said film is a blown film obtained by inflating, at a blow-up ratio of from 9 to 20, a laminate tubular film having an intermediate layer comprising a linear low-density polyethylene-based resin having an MFR of from 0.1 to 5 g/10 min and a Q-value of from 1 to 6, wherein said intermediate layer has laminated on both sides thereof a surface Layer comprising a copolymer resin comprising from 60 to 95% by weight of ethylene-based structural units and from 5 to 40% by weight of structural units derived from a monomer selected from the group consisting of vinyl acetate, aliphatic unsaturated carboxylic acids, and aliphatic unsaturated carboxylic acid alkyl esters.
Claim 7
Dependent Claim
22 words
A wrapping film as claimed in claim 5, wherein said blown film has a total thickness of from 8 to 30 μm.
Claim 8
Dependent Claim
34 words
A wrapping film as claimed in claim 6, wherein said intermediate layer has a thickness of from 2 to 10 μm and each surface layer has a thickness of from 3 to 10 μm.
Claim 9
Dependent Claim
51 words
A wrapping resin film as claimed in claim 5, wherein said linear low-density polyethylene-based resin is a resin selected from the group consisting of ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-butene-1-hexene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers, wherein said resin has a density of from 0.89 to 0.93 g/cm 3 .
Claim 10
Dependent Claim
181 words
A wrapping film as claimed in claim 1, wherein said film is a blown film obtained by inflating, at a blow-up ratio of from 9 to 20, a laminate tubular film having an intermediate layer comprising from 80 to 95% by weight of a linear low-density polyethylene having an MFR of from 0.1 to 5 g/10 min and a Q-value of from 1 to 6 and from 5 to 20% by weight of a copolymer resin comprising from 60 to 95% by weight of ethylene-based structural units and from 5 to 40% by weight of structural units derived from a monomer selected from the group consisting of vinyl acetate, aliphatic unsaturated carboxylic acids, and aliphatic unsaturated carboxylic acid alkyl esters, wherein said intermediate layer has laminated on both sides thereof a surface layer comprising a copolymer resin comprising from 60 to 95% by weight of ethylene-based structural units and from 5 to 40% by weight of structural units derived from a monomer selected from the group consisting of vinyl acetate, aliphatic unsaturated carboxylic acids, and aliphatic unsaturated carboxylic acid alkyl esters.
Claim 11
Dependent Claim
22 words
A wrapping film as claimed in claim 9, wherein said blown film has a total thickness of from 8 to 30 μm.
Claim 12
Dependent Claim
34 words
A wrapping film as claimed in claim 10, wherein said intermediate layer has a thickness of from 2 to 10 μm and each surface layer has a thickness of from 3 to 10 μm.
Claim 13
Dependent Claim
50 words
A wrapping film as claimed in claim 9, wherein said linear low-density polyethylene-based resin is a resin selected from the group consisting of ethylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-1-butene-1-hexene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers, wherein said resin has a density of from 0.89 to 0.92 g/cm 3 .
Claim 14
Dependent Claim
131 words
A wrapping film as claimed in claim 1, wherein, said film is a blown film obtained by inflating, at a blow-up ratio of from 8 to 20, a laminate tubular film having an intermediate layer comprising from 10 to 90% by weight of a crystalline polyolefin-based resin selected from the group consisting of ethylene-based resins and propylene-based resins and from 10 to 90% by weight of an olefinic thermoplastic elastomer, wherein said intermediate layer has laminated on both sides thereof a surface layer comprising a copolymer resin comprising from 60 to 95% by weight of ethylene-based structural units and from 5 to 40% by weight of structural units derived from a monomer selected from the group consisting of vinyl acetate, aliphatic unsaturated carboxylic acids, and aliphatic unsaturated carboxylic acid alkyl esters.
Claim 15
Dependent Claim
22 words
A wrapping film as claimed in claim 13, wherein said blown film has a total thickness of from 8 to 30 μm.
Claim 16
Dependent Claim
34 words
A wrapping film as claimed in claim 14, wherein said intermediate layer has a thickness of from 2 to 10 μm and each surface layer has a thickness of from 3 to 10 μm.
Claim 17
Dependent Claim
34 words
A wrapping film as claimed in claim 5, wherein said surface layer or intermediate layer or both further contains at least one additive selected from the group consisting of lubricants, tackifiers, and nucleating agents.
Claim 18
Dependent Claim
33 words
A wrapping film as claimed in claim 9, wherein said surface layer or intermediate layer or both contains at least one additive selected from the group consisting of lubricants, tackifiers, and nucleating agents.
Claim 19
Dependent Claim
34 words
A wrapping film, as claimed in claim 13, wherein said surface layer or intermediate layer or both further contains at least one additive selected from the group consisting of lubricants, tackifiers, and nucleating agents.
Claim 20
Dependent Claim
27 words
A wrapping film as claimed in claim 16, wherein said at least one additive is present in a total amount of from 0.5 to 5% by weight.
Claim 21
Dependent Claim
27 words
A wrapping film as claimed in claim 17, wherein said at least one additive is present in a total amount of from 0.05 to 5% by weight.
Claim 22
Dependent Claim
27 words
A wrapping film as claimed in claim 18, wherein said at least one additive is present in a total amount of from 0.05 to 5% by weight.
Claim 23
Dependent Claim
39 words
A wrapping film as claimed in claim 16, wherein said lubricant is a compound selected from the group consisting of oleamide, stearamide, erucamide, glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol dioleate, and a polyethylene glycol adduct of the glyceride.
Claim 24
Dependent Claim
39 words
A wrapping film as claimed in claim 17, wherein said lubricant is a compound selected from the group consisting of oleamide, stearamide, erucamide, glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol dioleate, and a polyethylene glycol adduct of the glyceride.
Claim 25
Dependent Claim
39 words
A wrapping film as claimed in claim 18, wherein said lubricant is a compound selected from the group consisting of oleamide, stearamide, erucamide, glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol dioleate, and a polyethylene glycol adduct of the glyceride.
Claim 26
Dependent Claim
45 words
A wrapping film as claimed in claim 16, wherein said tackifier is a compound selected from the group consisting of castor oil derivatives, low-molecular viscous polybutylenes, and sorbitan higher fatty acid esters containing from 12 to 22 carbon atoms in the higher fatty acid moiety.
Claim 27
Dependent Claim
45 words
A wrapping film as claimed in claim 17, wherein said tackifier is a compound selected from the group consisting of castor oil derivatives, low-molecular viscous polybutylenes, and sorbitan higher fatty acid esters containing from 12 to 22 carbon atoms in the higher fatty acid moiety.
Claim 28
Dependent Claim
45 words
A wrapping film as claimed in claim 18, wherein said tackifier is a compound selected from the group consisting of castor oil derivatives, low-molecular viscous polybutylenes, and sorbitan higher fatty acid esters containing from 12 to 22 carbon atoms in the higher fatty acid moiety.
Claim 29
Dependent Claim
17 words
A wrapping film as claimed in claim 16, wherein said nucleating agent is talc or silica powder.
Claim 30
Dependent Claim
17 words
A wrapping film as claimed in claim 17, wherein said nucleating agent is talc or silica powder.
Claim 31
Dependent Claim
17 words
A wrapping film as claimed in claim 18, wherein said nucleating agent is talc or silica powder.
References Cited (Backward Citations)
US4367256A
Cited
EP0066149A1
Cited
US4542188A
Cited
EP0092897A2
Cited
JPS59190831A
Cited
US4478564A
Cited
DE3502136A1
Cited
US4551380A
Cited
EP0286430A2
Cited
US4833017A
Cited
EP0348749A2
Cited
EP0351744A2
Cited
EP0436196A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-04 | 1998-01-03 | 1998-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-04 | 2002-01-03 | 2002-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-04 | 2006-01-03 | 2006-07-05 | $7700.00 | Window Closed / Lapsed |