LAMINATE COMPOSITE

Abstract

A laminate composite composed of at least two laminations (1, 7) and an imprint located between them (3). The lamination (7) includes at least two layers (4, 5, 6). One layer (5) includes a UV absorber to protect the imprint. This layer (5) is characterized by having a lower density than the other layers (4, 6). The other layers (4, 6) preferably have a density that is higher relative to the one layer (5) by a factor of 1.005, in particular by a factor of 1.01, preferably by a factor of 1.015.

Claims

1. A laminate composite, comprising: first and second laminations, an imprint arranged between the first and second laminations, the second lamination comprises at least two layers, one of the layers comprises a UV absorber to protect the imprint, the one of the layers has a lower density relative to at least one of the other layers, and the other layers have a higher density relative to the one of the layers by a factor of at least 1.005.

2. The laminate composite as claimed in claim 1, wherein the layers are composed primarily of polyolefins.

3. The laminate composite as claimed in claim 1, wherein the one of the layers is composed primarily of at least one of an LDPE or an LLDPE.

4. The laminate composite as claimed in claim 2, wherein the other layers are composed primarily of at least one of an MDPE or an HDPE.

5. The laminate composite as claimed in claim 1, wherein the second lamination has a thickness of less than 60 μm.

6. The laminate composite as claimed in claim 1, wherein the one of the layers in the second lamination has a greater thickness relative to the other layers, and the thickness is greater by more than a factor of 1.1.

7. The laminate composite as claimed in claim 1, wherein the one of the layers comprises organic UV absorbers.

8. The laminate composite as claimed in claim 1, wherein the one of the layers comprises inorganic UV absorbers.

9. The laminate composite as claimed in claim 8, wherein a content of the UV absorber in the one of the layers is at least 1 wt. %.

10. The laminate composite as claimed in claim 1, wherein at least one of the layers in the second lamination contains UV stabilizers.

11. The laminate composite as claimed in claim 1, wherein the first lamination has a thickness of less than 200 μm.

12. The laminate composite as claimed in claim 1, wherein the one of the layers is embedded between two of the other layers which have a higher density.

13. A bag for bulk materials comprising the laminate composite as claimed in claim 1.

14. The laminate composite as claimed in claim 1, wherein the lamination has a thickness of more than 20 μm.

15. The laminate composite as claimed in claim 10, wherein the UV stabilizers are hindered amine light stabilizers (HALS).

16. The laminate composite as claimed in claim 11, wherein the first lamination has a thickness of more than 50 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further advantages and features of the invention can be found in the description of a working example with reference to a drawing and in the drawing itself.

[0039] FIG. 1 shows a section through a laminate composite according to the invention.

DETAILED DESCRIPTION

[0040] FIG. 1 shows a composite that comprises a base lamination 1 and a transparent imprint lamination 7 with an imprint 3 lying between them. The two laminations 1 and 7 are joined by means of a laminating agent 2.

[0041] The laminate composite is characterized by a novel imprint lamination 7. Its unique feature is its multilayer structure, which is characterized by polyethylene films of varying density. The laminate composite according to the invention thus provides a specific combination of features that are not known in laminated film compositions of the prior art. The specific combination of the layers makes it possible to equip a thin lamination 7 with an additive package that makes it possible, as a transparent imprint lamination, to provide weather resistance to an imprint 3 applied underneath it.

[0042] In the working example shown, a three-layer imprint lamination is used. Layer 5 is embedded between layers 4 and 6 and is composed primarily of LLDPE and/or LDPE with a density of 0.923 g/cm.sup.3.

[0043] The following components are used in the production of layer 5: 45% LLDPE, 40% LDPE, 10% UV absorber batch (20% active ingredient content), 5% UV stabilizer batch.

[0044] In the laminate composite, external layers 4 and 6, which do not have additive UV absorbers and UV stabilizers, function as a migration barrier for the absorber molecules in the middle layer 5.

[0045] The following components are used in the production of layers 4 and 6: 59% MDPE, 40% LLDPE, 1% anti-block batch in layer 4, and 55% MDPE, 40% LLDPE, 4% UV stabilizer batch, 1% anti-block batch in layer 6.

[0046] In the laminate composite according to the invention, the transparent imprint lamination 7 exhibits a total thickness of 30 μm. The ratio of the layer thicknesses is 30% for layer 4, 40% for layer 5 and 30% for layer 6. The imprint lamination 7 is produced by means of blown film coextrusion.

[0047] The thickness of the base lamination 1 is 80 μm in order to ensure the necessary stability in combination with the necessary flexibility of the laminate composite according to the invention. The white base lamination 1 is shown schematically in FIG. 1 as a monofilm. However, it has been found to be particularly advantageous to select a multilayer base lamination in particular in the form of a coextrusion film.

[0048] In the working example shown, the base lamination 1 has a three-layer configuration. The following components are used: 94% met. LLDPE, 6% additives (processing aid, white batch, filling material) in layer 1.1, 80% HDPE 10% LLDPE, 10% white batch and filling material in layer 1.2 and 94% met. LLDPE, 6% additives (processing aid, white batch, filling material) in layer 1.3.

[0049] Pigments are used for printing of the print image via reverse printing.

[0050] A polyurethane-based adhesive is used in lamination of the two laminations 1 and 7.

[0051] In conclusion, the composition of a particularly advantageous working example is shown in the following table:

TABLE-US-00001 Imprint 6 55% MDPE lamination 40% LLDPE 4% UV stabilizer batch 1% anti-block batch 5 45% LLDPE 40% LDPE 10% UV absorber batch (20% active ingredient content) 5% UV stabilizer batch 4 59% MDPE 40% LLDPE 1% anti-block batch Base 1.3 94% met. LLDPE lamination 6% additives (processing aid, white batch, filling material) 1.2 80% HDPE 10% LLDPE 10% white batch and filling material 1.1 94% met. LLDPE 6% additives (processing aid, white batch, filling material)

[0052] The laminate composite according to the invention exhibits particularly favorable product properties for use as packaging of bulk materials and also meets for the first time the requirement for weather-resistant imprints.