Method for producing sterilized oxygen-absorbing multilayer body

1. A method for producing a sterilized oxygen-absorbing multilayer body, comprising:

irradiating with radiation an oxygen-absorbing multilayer body comprising at least an oxygen-absorbing layer containing a transition metal catalyst and a thermoplastic resin (a) having a tetralin ring as a structural unit and a layer containing a thermoplastic resin (b); and

heating the oxygen-absorbing multilayer body which has been irradiated with radiation at a temperature of the glass transition temperature of the thermoplastic resin (a) minus 20° C. or more and lower than the glass transition temperature of the thermoplastic resin (a) for 50 hours or more.

2. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the oxygen-absorbing multilayer body comprises at least two layers containing a thermoplastic resin (b) and the oxygen-absorbing layer is disposed between the two layers containing a thermoplastic resin (b).

3. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the glass transition temperature of the thermoplastic resin (a) (Tg 1 ) and the glass transition temperature of the thermoplastic resin (b) (Tg 2 ) have the relation represented by the following equation (A):

Tg 1 ≤Tg 2 ≤[Tg 1 +10° C.]  Equation (A).

4. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the heating time is 50 hours or more and 120 hours or less.

5. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the heating temperature is a temperature of the glass transition temperature of the thermoplastic resin (a) minus 20° C. or more and the glass transition temperature of the thermoplastic resin (a) minus 5° C. or less.

6. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the oxygen-absorbing multilayer body is heated in the presence of oxygen.

7. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the thermoplastic resin (b) has a glass transition temperature of 60 to 80° C.

8. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the oxygen-absorbing multilayer body is an oxygen-absorbing multilayer container.

9. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein

the thermoplastic resin (a) is a polyester compound comprising at least one structural unit having a 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, wherein the monovalent substituent 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 the 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.

10. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the transition metal catalyst contains at least one transition metal selected from the group consisting of manganese, iron, cobalt, nickel, and copper.

11. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the transition metal catalyst is contained in an amount of 0.0001 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).

12. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the thermoplastic resin (a) is a polyester compound comprising at least one structural unit having a tetralin ring selected from the group consisting of the following general formulas (5) to (7):

13. The method for producing a sterilized oxygen-absorbing multilayer body according to claim 1 , wherein the radiation is gamma rays, X-rays, or electron beams.