← Back to Patent Explorer
US4393115A Expired / Lapsed US ⏱️ 0.0 years remaining

Multilayered polypropylene film

Assignee: Toray Industries Inc
•
Filing: 1981-07-15
•
Granted: 1983-07-12
•
Expires: 2001-07-15
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

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.

Inventors

  • 👤 Toshiya Yoshii
  • 👤 Satoru Nakura
  • 👤 Masatsugi Murakami

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 02:30
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B7/00; B32B7/04; B32B7/12; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/516; B32B2307/518; B32B2323/00; B32B2323/10; B32B2405/00; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/25; Y10T428/252; Y10T428/256; Y10T428/257; Y10T428/258; Y10T428/259; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/2848; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31938

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 63 words
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
Dependent Claim 63 words
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 3
Dependent Claim 80 words
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 μm, and wherein the total thickness of said multilayered polypropylene film is in the range between about 15 and 60 μm.
Claim 4
Dependent Claim 38 words
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 5
Dependent Claim 15 words
A multilayered polypropylene film as claimed in claim 3, wherein said percentage is about 10-30%.
Claim 6
Dependent Claim 21 words
A multilayered polypropylene film as claimed in claim 3, wherein said fine particles have sizes of about 0.1 to 10 μm.
Claim 7
Dependent Claim 21 words
A multilayered polypropylene film as claimed in claim 5, wherein said fine particles have sizes of about 0.5 to 5 μm.
Claim 8
Dependent Claim 35 words
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 9
Dependent Claim 18 words
A multilayered polypropylene film as claimed in claim 7, wherein said ethylene content is about 10 to 30%.
Claim 10
Dependent Claim 35 words
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 11
Dependent Claim 18 words
A multilayered polypropylene film as claimed in claim 9, wherein the content of said polyethylene is about 2-20%.
Claim 12
Dependent Claim 34 words
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 13
Dependent Claim 33 words
A multilayered polypropylene film as claimed in claim 1, wherein the block copolymer has a ratio of absorbence at 720 cm -1 to absorbence at 731 cm -1 of about 0.4 to 3.0.
Claim 14
Dependent Claim 17 words
A multilayered polypropylene film as claimed in claim 12, wherein said ratio is about 0.6 to 2.0.
Claim 15
Dependent Claim 21 words
A multilayered polypropylene film as claimed in claim 1, wherein said stretching is uniaxial and the stretch ratio is about 3-12.
Claim 16
Dependent Claim 16 words
A multilayered polypropylene film as claimed in claim 14, wherein said stretch ratio is about 5-10.
Claim 17
Dependent Claim 26 words
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 18
Dependent Claim 15 words
A multilayered polypropylene film as claimed in claim 16, wherein said ratio is about 40-60.
Claim 19
Dependent Claim 34 words
A multilayered polypropylene film as claimed in claim 1, wherein the biaxially oriented polypropylene layer has a refraction index at 589 mμ above 1.501 in both the longitudinal and transverse directions of the film.
Claim 20
Dependent Claim 15 words
A multilayered polypropylene film as claimed in claim 18, wherein said index is above 1.505.
Claim 21
Dependent Claim 41 words
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 mμ smaller than 1.505 in the longitudinal direction and larger than 1.510 in the transverse direction.

References Cited (Backward Citations)

US3515626A Cited
US3887745A Cited
US4132050A Cited
JPS5593450A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-07-11 1987-01-10 1987-07-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-07-11 1991-01-10 1991-07-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-07-11 1995-01-10 1995-07-12 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag