Oxygen scavenging composition for low temperature use

• US 5,648,020 A
• Filed: 12/06/1995
• Issued: 07/15/1997
• Est. Priority Date: 10/01/1992
• Status: Expired due to Term

• Current Assignee: Cryovac Incorporated (Sealed Air)
• Original Assignee: W R Grace & Company - CONN (WR Grace & Company)
• Inventors: Speer, Drew Ve, Roberts, William Peyton
• Primary Examiner(s): ANTHONY, JOSEPH DAVID
• Application Number:
  US08/569,373
• Time in Patent Office: 587 Days
• Field of Search: 252/188.28, 252/181.3, 526/90, 526/335, 206/524.2, 502/402, 502/49, 428/411.1
• US Class Current: 252/188.28
• CPC Class Codes: A23L 3/3436 Oxygen absorbent
• CPC Class Codes: C08K 5/0008 Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
• CPC Class Codes: C08K 5/0091 Complexes with metal-heteroatom-bonds
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

Improved compositions for scavenging oxygen are disclosed. These materials, characterized by low degree crystallinity and a glass transition temperature of lower than -15° C., have high oxygen scavenging rates at low temperatures. The composition comprises an ethylenically unsaturated hydrocarbon and a transition metal salt catalyst and can be incorporated into various types of layers. It is preferable that the composition be incorporated into layers of multilayered articles used for packaging oxygen-sensitive products such as food products.

Claims

1. An oxygen scavenging composition in the form of a film, said composition comprising

(1) an oxygen scavenging system consisting essentially of

(a) an ethylenically unsaturated hydrocarbon polymer having a weight average molecular weight of at least about 1,000, and a glass transition temperature (Tg) of lower than -15°

C., and

(b) from 10 to 10,000 ppm of transition metal in the form of a transition metal salt; and

(2) a photoinitiator or mixtures of photoinitiator;

said composition has an oxygen absorption rate of at least 10 cc O₂ per m² per day at a temperature of 4°

C. and an oxygen absorption capacity of at least 250 cc oxygen per m² per mil thickness.

2. The composition according to claim 1 wherein the ethylenically unsaturated hydrocarbon polymer (a) has a glass transition temperature of lower than -25°

C.

3. The composition according to claim 1 wherein polymer (a) is selected from the group consisting of atactic 1,2-polybutadiene, EPDM rubbers, polyoctenamer, 1,4-polybutadiene, or block or graft copolymers thereof, partially polymerized unsaturated fatty acids and their esters, and mixtures thereof.

4. The composition according to claim 3 wherein the ethylenically unsaturated hydrocarbon polymer (a) has a glass transition temperature of lower than -25°

C.

5. The composition according to claim 3 wherein the photoinitiator is selected from the group consisting of benzophenone, o-methoxybenzophenone, acetophenone, o-methyoxy-acetophenone, acenaphthenequinone, methyl ethyl ketone, valerophenone, hexanophenone, α

-phenyl-butyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholinobenzophenone, benzoin, benzoin methyl ether, 4-o-morpholinodeoxybenzoin, p-diacetylbenzene, 4-aminobenzophenone, 4'"'"'-methoxyacetophenone, α

-tetralone, 9-acetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenone, 3-acetylphenanthrene, 3-acetylindole, 9-fluorenone, 1-indanone, 1,3,5-triacetylbenzene, thioxanthen-9-one, xanthene-9-one, 7-H-benz(de)anthracen-7-one, bezoin tetrahydropyranyl ether, 4,4'"'"'-bis(dimethylamine)benzophenone, 1'"'"'-acetonaphthone, 2'"'"'-acetonaphthone, acetonaphthone and 2,3-butanedione, benz(a)anthracene-7,12-dione, 2,2-dimethyoxy-2-2phenylacetophenone, α

,α

-diethoxyacetophenone, α

,α

-dibutoxyacetophenone, methylene blue, tetraphenyl porphine, and mixtures thereof.

6. The composition according to claim 5 wherein the photoinitiator is selected from the group consisting of benzophenone, substituted benzophenone, acetophenone, substituted acetophenone, acetonaphthone, substituted acetonaphthone and mixtures thereof.

7. The composition according to claim 1 wherein the photoinitiator is selected from the group consisting of benzophenone, o-methoxybenzophenone, acetophenone, o-methyoxy-acetophenone, acenaphthenequinone, methyl ethyl ketone, valerophenone, hexanophenone, α

-phenyl-butyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholinobenzophenone, benzoin, benzoin methyl ether, 4-o-morpholinodeoxybenzoin, p-diacetylbenzene, 4-aminobenzophenone, 4'"'"'-methoxyacetophenone, α

-tetralone, 9-acetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenone, 3-acetylphenanthrene, 3-acetylindole, 9-fluorenone, 1-indanone, 1,3,5-triacetylbenzene, thioxanthen-9-one, xanthene-9-one, 7-H-benz(de)anthracen-7-one, bezoin tetrahydropyranyl ether, 4,4'"'"'-bis(dimethylamine)benzophenone, 1'"'"'-acetonaphthone, 2'"'"'-acetonaphthone, acetonaphthone and 2,3-butanedione, benz(a)anthracene-7,12-dione, 2,2-dimethyoxy-2-2phenylacetophenone, α

,α

-diethoxyacetophenone, α

,α

-dibutoxyacetophenone, methylene blue, tetraphenyl porphine, and mixtures thereof.

8. The composition according to claim 7 wherein the photoinitiator is selected from the group consisting of benzophenone, substituted benzophenone, acetophenone, substituted acetophenone, acetonaphthone, substituted acetonaphthone and mixtures thereof.

9. The composition according to claim 7 wherein the ethylenically unsaturated hydrocarbon polymer (a) has a glass transition temperature of lower than -25°

C.

10. A product in the form of a multilayer flexible film having at least one layer of said film comprising the composition of claim 1, 3, 7, 5, 8, 6, 2, 4, or 9 and said flexible film has an oxygen transmission of <

1 cc O₂ /(m² ·

day·

atm) at 25°

C.