Food packaging laminates

Abstract

The invention relates to a flexible packaging. Specifically, this invention relates to a laminate, the use of the laminate in the packaging of food, drinks, medicine and toys, and a corresponding package. The laminate can be a film-to-film and film-to-foil laminates, suitable for typical food packaging uses, using hot melt laminating adhesives. Such laminates are substantially fee from volatile contaminates, especially migratable isocyanates and aromatic amines.

Description

REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 433,027, filed Nov. 26, 2003, which was the National Stage of International Application No. PCT / EP01 / 12879, filed Nov. 7, 2001, which claims the benefit of U.S. Provisional Application No. 60 / 253,903, filed Nov. 29, 2000, all of which are incorporated herein.BACKGROUND OF THE INVENTION [0002] The invention relates to a flexible packaging. Specifically, this invention relates to a laminate, the use of the laminate in the packaging of food, drinks, medicine and toys, methods of producing such laminates, methods of packaging articles and a corresponding package. [0003] It is well known to package food in wraps, bags, pouches etc. made of laminates. Preferred materials for food packaging often consist of a first substrate, such as a film, which is generally thin and transparent, but can be printable, and a second substrate which can be another, (often thicker) film, a metal f...

AI Technical Summary

Benefits of technology

[0088] A substantial advantage of the present invention is that a substantially continuous coating layers can be made from hot melts at very low coating weights. Even with customary commercially available hot melts, continuous layers can be produced at coating weights ranging from about 0.5 g / m2 to as much as 50-60 g / m2, preferably at coating weights of not more than about 20 g / m2, more preferably at coating weights of not more than 10 g / m2, even more preferably between 3 g / m2 and 5 g / m2 and most preferably less than 3 g / m2. However, coating weights higher than 60 g / m2 may be useful for other applications wherein reducing the mechanical and heat-induced stresses is of primary importance.

[0089] The very thin coatings which can be produced according to the invention not only contribute to the economical advantages of the inventive method, but also makes it possible to achieve a very much reduced stiffness of the material, which thus comes much closer, in its properties, to uncoated substrates.

[0090] The invention also concerns foodstuff items packaged in accordance with the invention. The use of such flexible laminating materials as packaging material for the food, drink and drug industries has the major advantage of avoiding contamination of the packaged items by volatile and / or migratable packaging material components such as monomers. This makes it possible to produce packaging laminate materials for the food industry advantageously from solvent-free hot melt laminate adhesives, without incurring the danger of contaminating the food with monomers and their reacting products. At the same time, optically very advantageous laminates are obtained, which are not inferior, but quite often superior, in these aspects than state-of-the-art laminates.

[0091] Specifically, the present invention is related to the use of a flexible laminate material comprising a polymer plastics material film laminated onto a second substrate by means of a hot melt laminating adhesive, as a packaging material to reduce contamination of packaged goods, especially food, by volatile packaging material components, such as monomers or ologomers. Such volatile and / or migratable components can include isocyanates and / or aromatic amines.

[0092] These foodstuffs can be selected from all foodstuffs which have been packaged, are currently packaged or may in the future be packaged using laminated packaging material as above disclosed. Specifically, these will be items such as medicine, snack foods and confectionery, aqueous and moist foods, dry foodstuffs, coffee, tea and such goods, heat-treated and steamed, as well as autoclaved goods, but also fresh fruit, fresh vegetables, fresh meats, fish and cheese, as well as corresponding items for deep freezing and other low temperature preservation purposes. Vacuum preservation packaging is included, and the packed food items of the invention further include prepared food for reheating, as well as beverages. Thus, the invention includes the packaging of milk in film bags, as well as fruit and vegetable juices and alcoholic beverages such as wine.

[0093] In addition, such laminates can be used as capseals for various food, drink and medicine packaging, as well as aseptic packaging of food and drink items mentioned above. Also, other non-food uses can include packaging of toys for example, for small children and babies, who may put such items in their mouths, are expressly within the scope of the present invention. Also, boxes and pouches for baked goods are contemplated.

Problems solved by technology

Whereas in the past, such film-to-film and film-to-foil laminations were often produced using volatile organic solvent-based laminating adhesives, environmental and regulatory restrictions have in the more recent past caused the industry to use waterborne adhesives, especially polyurethane dispersions and acrylic emulsions.

However, film-to-film and film-to-foil laminates using solvent-free reactive laminating adhesives, even including two-component polyurethane laminating adhesives, may lead to problems specifically in food.

Such careful curing requires time and energy expenditure.

Whereas in many applications of laminated materials, such monomer contamination does not present a problem, this is not true in the food industry, since the monomers may migrate into the food, which is not acceptable.

Specifically, the use of reactive polyurethane adhesives has in some cases been found to lead to contamination of the packaged food with unreacted isocyanates and carcinogenic aromatic amines (probably formed by reaction of adhesive components with moisture from the food).

Thus, food packaging materials may release volatile and / or migratable contaminations which result from the adhesives used in manufacturing such materials.

This problem is, as far as the food industry is concerned, acerbated by the need for just-in-time production and delivery, such restraints actually promoting the use of not fully cured laminates.

Contact with the body means the possibility of undesired contamination of the body by volatiles and / or migratables as defined above.

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