§
PatentCue
Patent Intelligence
Join Waitlist Sign In
← Back to Patent Explorer
US5726220A Expired / Lapsed US ⏱️ 0.0 years remaining

Biodegradable polymer compositions and shrink films

Assignee: Shin-Etsu Chemical Co Ltd
•
Filing: 1996-08-28
•
Granted: 1998-03-10
•
Expires: 2016-08-28
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The present invention provides polylactic compositions effecting an excellent mold releasability upon processing and significantly improved elongation at break and impact strength without affecting the transparency. Also provided is a shrink film which decomposes under the natural environment and has excellent transparency, flexibility, shrinkability and mold releasability upon processing by applying the polylactic acid composition to a shrink film. There is provided a biodegradable polymer composition comprising 100 parts by weight of polylactic acid and 5 to 70 parts by weight of EVA. Further, a biodegradable polymer composition is provided comprising the polymer composition with one or more additives selected from the group consisting of 0.05 to 5 parts by weight of a lubricant, 1 to 50 parts by weight of plasticizer, 0.5 to 5 parts by weight of thermal stabilizer and 0.05 to 5 parts by weight of mold releasing agent. These biodegradable polymer compositions are applied to shrink films.

Inventors

  • 👤 Yuji Tokushige
  • 👤 Norio Nakamura
  • 👤 Yoichi Tanifuji
  • 👤 Shuhei Ueda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 19:37
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/0008; C08L; C08L67/00; C08L67/04; C08K2201/00; C08K2201/015; C08K2201/018

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 35 words
A biodegradable polymer composition comprising a polylactic acid and an ethylene vinyl acetate copolymer having an ethylene content of 20 to 40% by weight and a vinyl acetate content of 60 to 80% by weight.
Claim 2
Dependent Claim 35 words
A biodegradable polymer composition comprising a polylactic acid and an ethylene vinyl acetate copolymer having an ethylene content of 20 to 40% by weight and a vinyl acetate content of 60 to 80% by weight.
Claim 3
Dependent Claim 57 words
A biodegradable polymer composition comprising a polylactic acid, an ethylene vinyl acetate copolymer having an ethylene content of 20 to 40% by weight and a vinyl acetate content of 60 to 80% by weight, and one or more additives selected from the group consisting of a lubricant, a plasticizer, a thermal stabilizer and a mold release agent.
Claim 4
Dependent Claim 57 words
A biodegradable polymer composition comprising a polylactic acid, an ethylene vinyl acetate copolymer having an ethylene content of 20 to 40% by weight and a vinyl acetate content of 60 to 80% by weight, and one or more additives selected from the group consisting of a lubricant, a plasticizer, a thermal stabilizer and a mold release agent.
Claim 5
Dependent Claim 35 words
The biodegradable polymer composition according to claim 2, wherein the thermal stabilizer is 0.5 to 5 parts by weight, against 100 parts by weight of the polylactic acid, of an inorganic salt of lactic acid.
Claim 6
Dependent Claim 38 words
The biodegradable polymer composition according to claim 2, wherein 0.05 to 5 parts by weight, against on 100 parts by weight of the polylactic acid, of one or more silicone oils are added as said mold release agent.
Claim 7
Dependent Claim 28 words
The biodegradable polymer composition according to claim 2, wherein said mold release agent is a silicone oil having a viscosity of 100 to 10,000 cs at 25° C.
Claim 8
Dependent Claim 65 words
The biodegradable polymer composition according to claim 2 wherein said mold release agent is one or more selected from the group consisting of alkyl-modified silicones, methylstyryl-modified silicones, methacrylic acid-modified silicones, polyether-modified silicones, C 16 and higher fatty acid-containing silicones, C 16 and higher fatty acid-modified silicones, C 16 and higher fatty acid ester-modified silicones, C 16 and higher fatty acid alkoxy-modified silicones and fluorine-modified silicones.
Claim 9
Dependent Claim 12 words
A biodegradable shrink film comprising a biodegradable polymer composition of claim 1.
Claim 10
Dependent Claim 12 words
The biodegradable shrink film comprising a biodegradable polymer composition of claim 2.
Claim 11
Dependent Claim 35 words
A biodegradable polymer composition according to claim 1, wherein said ethylene vinyl acetate copolymer is added in an amount of 5 to 70 parts by weight against 100 parts by weight of said polylactic acid.
Claim 12
Dependent Claim 31 words
A biodegradable polymer composition according to claim 2, wherein said mold release agent is one or more compounds selected from the group consisting of alkyl-modified silicones, methylstyryl-modified silicones, and mixtures thereof.

References Cited (Backward Citations)

US5387623A Cited
US5470526A Cited
US5252646A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-03-09 2001-09-08 2002-03-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-03-09 2005-09-08 2006-03-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-03-09 2009-09-08 2010-03-10 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag