Sterilized oxygen-absorbing resin composition, sterilized oxygen-absorbing multilayer container and method for producing the same

Patent metadata

Field	Value
Publication number	US-9637604-B2
Application number	US-201515115787-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Feb 6, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

The present invention provides a sterilized oxygen-absorbing resin composition obtained by performing at least: a sterilizing step of irradiating with radiation an oxygen-absorbing resin composition containing a transition metal catalyst and a thermoplastic resin (a) having a tetralin ring as a constituent unit; and a step of heating the oxygen-absorbing resin composition at a temperature equal to or higher than the glass transition temperature of the thermoplastic resin (a) and equal to or lower than 200° C., after the sterilizing step.

First claim

The invention claimed is:

1. A sterilized oxygen-absorbing resin composition obtained by performing at least:
a sterilizing step of irradiating with radiation an oxygen-absorbing resin composition comprising a transition metal catalyst and a thermoplastic resin (a) having a tetralin ring as a constituent unit; and
a step of heating the oxygen-absorbing resin composition at a temperature equal to or higher than a glass transition temperature of the thermoplastic resin (a) and equal to or lower than 200° C., after the sterilizing step.

2. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein a time of the heating is 1 to 120 minutes.

3. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein the thermoplastic resin (a) is a polyester compound comprising a constituent unit having at least one tetralin ring selected from the group consisting of the following general formulas (1) to (4):

wherein R independently represents a hydrogen atom or a monovalent substituent; the monovalent substituent is at least one selected from the group consisting of a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a thiol group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group, these of which may further have a substituent; m represents an integer of 0 to 3; n represents an integer of 0 to 7; at least one hydrogen atom is bonded to a benzylic position of the tetralin ring; and X represents a divalent group comprising at least one group selected from the group consisting of an aromatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a linear or branched, saturated or unsaturated aliphatic hydrocarbon group, and a heterocyclic group.

4. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein the transition metal catalyst comprises at least one transition metal selected from the group consisting of manganese, iron, cobalt, nickel, and copper.

5. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein the transition metal catalyst is contained in an amount of 0.001 to 10 parts by mass in terms of the amount of a transition metal based on 100 parts by mass of the thermoplastic resin (a).

6. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein the constituent unit represented by the general formula (1) is at least one selected from the group consisting of the following formulas (5) to (7).

7. The sterilized oxygen-absorbing resin composition according to claim 1 , wherein the radiation is at least one selected from the group consisting of gamma rays, X-rays, and electron beams.

8. A sterilized oxygen-absorbing multilayer container obtained by performing at least:
a sterilizing step of irradiating with radiation an oxygen-absorbing multilayer container comprising an oxygen-absorbing multilayer body, wherein the oxygen-absorbing multilayer body comprises at least an oxygen absorbing layer (layer A) comprising an oxygen-absorbing resin composition comprising a transition metal catalyst and a thermoplastic resin (a) having a tetralin ring as a constituent unit and a layer (layer B) comprising a thermoplastic resin (b) formed on the oxygen absorbing layer (layer A); and
a step of heating the oxygen-absorbing multilayer container at a temperature equal to or higher than a glass transition temperature of the thermoplastic resin (a) and equal to or lower than 200° C., after the sterilizing step.

9. The sterilized oxygen-absorbing multilayer container according to claim 8 , wherein:
the oxygen-absorbing multilayer container comprises an oxygen-absorbing multilayer body having three or more layers, the oxygen-absorbing multilayer body comprising at least
the oxygen absorbing layer (layer A),
a layer (layer B1) comprising a thermoplastic resin (b1) formed on one surface of the oxygen absorbing layer (layer A), and
a layer (layer B2) comprising a thermoplastic resin (b2) formed on an other surface of the oxygen absorbing layer (layer A); and

the temperature of the heating step is equal to or higher than the glass transition temperature of the thermoplastic resin (a) and equal to or lower than either a glass transition temperature of the thermoplastic resin (b1) or a glass transition temperature of the thermoplastic resin (b2).

10. A method for producing a sterilized oxygen-absorbing multilayer container, comprising:
a sterilizing step of irradiating with radiation an oxygen-absorbing multilayer container comprising an oxygen-absorbing multilayer body, wherein the oxygen-absorbing multilayer body comprises at least an oxygen absorbing layer (layer A) comprising an oxygen-absorbing resin composition comprising a transition metal catalyst and a thermoplastic resin (a) having a tetralin ring as a constituent unit and a layer (layer B) comprising a thermoplastic resin (b) formed on the oxygen absorbing layer (layer A); and
a step of heating the oxygen-absorbing multilayer container at a temperature equal to or higher than a glass transition temperature of the thermoplastic resin (a) and equal to or lower than 200° C., after the sterilizing step.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Ito Fumihiro
• Okada Satoshi
• Iwamoto Shinpei

Classifications

• C08G63/189

  containing a naphthalene ring · CPC title

• B32B2439/70

  Food packaging · CPC title

• B32B27/06

  as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title

• A61L2/08

  Radiation · CPC title