Claims
- 1. Biologically degradable film composed of
- a synthetic polymer and
- biologically degradable polymer particles having a particle size smaller than about 10 .mu.m, said biologically degradable polymer particles being homogeneously distributed in said synthetic polymer,
- said particles of said biologically degradable polymer being coated with enzymes in an amount effective to degrade said biologically degradable polymer when said enzyme is exposed to moisture, said particles being further coated with an oxidizable outer coating comprising vegetable-based oil, said oil coating being present in an effective amount to prevent moisture from contacting said enzymes and thereby temporarily preventing the degradation of said biologically degradable polymer by said enzymes after said biologically degradable polymer particles have attained a particle size smaller than about 10 .mu.m, said oil coating when oxidized allowing moisture to contact said enzymes and thereby degrade said biologically degradable polymer.
- 2. Biologically degradable film of claim 1 further comprising a catalyst which catalyzes oxidation of said oil coating.
- 3. Film according to claim 2 wherein said catalyst is Fe.sup.3+, Cu.sup.2+, Se.sup.2+ or Zn.sup.2+ and is present in an amount from about 0.01% to about 0.1% by weight of said film.
- 4. Film according to claim 2 wherein said film contains about 0.01-0.1% catalyst by weight of said film, about 10-60% biologically degradable polymer particles by weight of said film and about 40-90% synthetic polymer by weight of said film.
- 5. Biologically degradable film of claim 2, wherein the proportions of said biologically degradable polymer and said catalyst in said biologically degradable film are sufficient to provide physical contact between said particles of said biologically degradable polymer and said catalyst through said oil coating.
- 6. Film according to claim 1 wherein the thickness of said film is between about 10-80 .mu.m.
- 7. Film according to claim 1 wherein the amount of said particles of said biologically degradable polymer in said film is from about 10% to about 60% by weight of said film.
- 8. Film according to claim 1 wherein said biologically degradable polymer is a starch and said synthetic polymer has a melting index of about 4.
- 9. Film according to claim 8 wherein said synthetic polymer is polyethylene.
- 10. Film according to claim 1, wherein the proportions of said biologically degradable polymer particles in said film are sufficient to provide physical contact between said particles of said biologically degradable polymer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
894734 |
Oct 1989 |
FIX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/732,412 now abandoned, filed Jul. 19, 1991 which in turn is a divisional of application Ser. No. 07/592,616 filed on Oct. 4, 1990 now U.S. Pat. No. 5,133,909.
US Referenced Citations (23)
Foreign Referenced Citations (11)
Number |
Date |
Country |
0230143 |
Jul 1987 |
EPX |
83920 |
Oct 1990 |
FIX |
891906 |
Dec 1990 |
FIX |
1483838 |
Aug 1977 |
GBX |
1485833 |
Sep 1977 |
GBX |
1487050 |
Sep 1977 |
GBX |
2029836 |
Mar 1980 |
GBX |
1600497 |
Oct 1981 |
GBX |
8806609 |
Sep 1988 |
WOX |
8910381 |
Nov 1989 |
WOX |
9201743 |
Feb 1992 |
WOX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
592616 |
Aug 1990 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
732412 |
Jul 1991 |
|