Method for degrading biodegradable resin

Patent metadata

Field	Value
Publication number	US-2016229979-A1
Application number	US-201415025151-A
Country	US
Kind code	A1
Filing date	Sep 25, 2014
Priority date	Sep 27, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

An object of the present invention is to provide a method for efficiently degrading a biodegradable resin. In particular, the present invention relates to a method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present. Further, the present invention relates to a method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in an enzymatic reaction liquid containing a biodegradable resin-degrading enzyme having an optimum concentration, wherein the degradation is conducted in a reaction liquid having an enzyme concentration which gives a biodegradable resin degradation ratio of 60% or higher, where a biodegradable resin degradation ratio at said optimum concentration is referred to as 100%.

First claim

1 . A method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein
no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present, wherein: the buffer component in the buffer solution is selected from the group consisting of tris aminomethane, 2-(cyclohexylamino)ethanesulfonic acid and combinations thereof, and the biodegradable resin-degrading enzyme is an alkaline protease selected from the group consisting of Proteinase K, Esperase, Savinase and combinations thereof.

2 . The method according to claim 1 , wherein the buffer component in the buffer solution is tris aminomethane.

3 . (canceled)

4 . The method according to claim 1 , wherein the biodegradable resin-degrading enzyme is Proteinase K.

5 . The method according to claim 1 , wherein the biodegradable resin comprises a polylactic acid-based resin.

6 . The method according to claim 1 , wherein the biodegradable resin is in a form of a pellet, a film, a powder, a single-layer fiber, a core-sheath fiber, or a capsule.

7 . The method according to claim 1 , wherein the biodegradable resin-degrading enzyme is Esperase.

8 - 9 . (canceled)

10 . The method according to claim 1 , wherein the biodegradable resin-degrading enzyme is Savinase.

11 . The method according to claim 1 , wherein the buffer component in the buffer solution is 2-(cyclohexylamino)ethanesulfonic acid.

12 . A method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein
no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present, wherein: the buffer component in the buffer solution is selected from the group consisting of tris aminomethane, 2-(cyclohexylamino)ethanesulfonic acid and combinations thereof, and the biodegradable resin comprises a polylactic acid-based resin.

13 . The method according to claim 12 , wherein the biodegradable resin-degrading enzyme is an alkaline protease.

14 . The method of claim 13 , wherein the alkaline protease is selected from the group consisting of Proteinase K, Esperase, Savinase and combinations thereof.

15 . The method according to claim 12 , wherein the biodegradable resin is in a form of a pellet, a film, a powder, a single-layer fiber, a core-sheath fiber, or a capsule.

16 . The method according to claim 12 , wherein the buffer component in the buffer solution is tris aminomethane.

17 . The method according to claim 12 , wherein the buffer component in the buffer solution is 2-(cyclohexylamino)ethanesulfonic acid.

18 . A method for degrading a biodegradable resin, the method comprising degrading the biodegradable resin in a buffer solution containing a biodegradable resin-degrading enzyme having an optimum pH of 7.5 or higher, wherein
no anion derived from a buffer component is present on one side of an equilibrium equation of buffering of the buffer solution, and a pH of the buffer solution is adjusted within a pH range which gives conditions for shifting the equilibrium towards the side on which no anion is present, wherein: the biodegradable resin-degrading enzyme is an alkaline protease selected from the group consisting of Proteinase K, Esperase, Savinase and combinations thereof, and the biodegradable resin comprises a polylactic acid-based resin.

19 . The method according to claim 18 , wherein the buffer component in the buffer solution is selected from the group consisting of tris aminomethane, 2-(cyclohexylamino)ethanesulfonic acid and combinations thereof.

20 . The method according to claim 19 , wherein the buffer component in the buffer solution is tris aminomethane.

21 . The method according to claim 19 , wherein the buffer component in the buffer solution is 2-(cyclohexylamino)ethanesulfonic acid.

22 . The method according to claim 18 , wherein the biodegradable resin-degrading enzyme is Proteinase K.

23 . The method according to claim 18 , wherein the biodegradable resin-degrading enzyme is Esperase.

24 . The method according to claim 18 , wherein the biodegradable resin-degrading enzyme is Savinase.

25 . The method according to claim 18 , wherein the biodegradable resin is in a form of a pellet, a film, a powder, a single-layer fiber, a core-sheath fiber, or a capsule.

Assignees

• Toyo Seikan Group Holdings Ltd

Inventors

• Katayama Tsutaki

Classifications

• C08J2300/16

  Biodegradable polymers · CPC title

• C08J11/105 Primary

  by treatment with enzymes · CPC title

• C08J2367/04

  Polyesters derived from hydroxy carboxylic acids, e.g. lactones (C08J2367/06 takes precedence) · CPC title

• B09B3/70

  Chemical treatment, e.g. pH adjustment or oxidation (involving an extraction step B09B3/80) · CPC title

• Y02W30/62

  Plastics recycling; Rubber recycling · CPC title