A kind of thin and high-rigidity label film

Abstract

The present invention discloses a thinned high-rigidity label film. Among them, the thinned high-rigidity label film comprises an inner layer, a core layer and a printing layer which are sequentially stacked from bottom to top. Among them, the inner layer comprises 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight percentage; the core layer comprises one or two of 15-80% of a second polyethylene and a third polyethylene, and 30-60% of a first polyethylene by weight percentage; the printing layer comprises 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight percentage; the first polyethylene is a high-density polyethylene with a melt index ≥ 5.0 g / 10 min and a melting point ≥ 120 °C; the second polyethylene is a low-density polyethylene with a melt index ≤ 4.0 g / 10 min and a melting point ≥ 100 °C; the melt index of the third polyethylene is 0.5-3.0 g / 10 min and the melting point ≥ 100 °C. The label film provided by the present invention has comprehensive properties of reduced thickness, good rigidity and moderate coefficient of friction.

Description

Technical Field

[0001] The invention relates to the technical field of labels, and in particular to a thinned high-stiffness label film. Background Art

[0002] Good products cannot be separated from good-looking outer packaging, and labels are also indispensable as a way to highlight the company's image. The corresponding label film is such an existence. A good label carries complete product information and display effects, and also highlights the temperament and personality of the product itself, which plays a finishing touch to the product packaging. Typical PE label films have many advantages such as high transparency, bright and beautiful printing colors, good wear resistance, good heat sealability, easy perforation, opening strips and palm-to-strip separation. They are widely used in the packaging of food, beverages and other consumer goods, such as juice, pet food, bottled water, medicines, cosmetics, lawn care products and auto parts.

[0003] Nowadays, labels tend to be lightweight and thinner, but if the thickness of PE is not thick enough, the mechanical strength or stiffness is insufficient, which will lead to poor printing overprint, deformation or breakage when assembling labels on the machine, and easy blistering when compounded with the base paper. In particular, some label products used in high-speed equipment and high-end have higher requirements for PE label film. At present, the domestic market is lacking such lightweight, high-strength and high-stiffness label film.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a thinned high-stiffness label film, aiming to solve the problem that the existing label film cannot take into account both the requirements of thickness reduction and stiffness.

[0006] The technical solution of the present invention is as follows:

[0007] A thinned high-stiffness label film, wherein the thinned high-stiffness label film comprises an inner layer, a core layer and a printing layer which are sequentially stacked from bottom to top, wherein the inner layer comprises 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight; the core layer comprises 15-80% of one or two of a second polyethylene and a third polyethylene by weight, and 30-60% of the first polyethylene; the printing layer comprises 25-55% of the first polyethylene and 40-70% of the second polyethylene by weight; the first polyethylene is a high-density polyethylene with a melting index of ≥5.0 g / 10 min and a melting point of ≥120° C.; the second polyethylene is a low-density polyethylene with a melting index of ≤4.0 g / 10 min and a melting point of ≥100° C.; the third polyethylene has a melting index of 0.5-3.0 g / 10 min and a melting point of ≥100° C.

[0008] The described thinned high-rigidity label film, wherein the core layer further comprises 5-25% of a fourth polyethylene by weight percentage, the melt index of the fourth polyethylene is 0.1-2.5 g / 10 min, and the melting point is ≥105 °C.

[0009] The described thinned high-rigidity label film, wherein the printing layer further comprises 1-5% of a fifth polyethylene by weight percentage, and the melt index of the fifth polyethylene is 0.1-3.0 g / 10 min.

[0010] The described thinned high-rigidity label film, wherein the fifth polyethylene is prepared by blending and modifying polyethylene with inorganic particles.

[0011] The described thinned high-rigidity label film, wherein the inorganic particles are one or more of natural silica, natural diatomite, synthetic silica, and synthetic glass beads.

[0012] The described thinned high-rigidity label film, wherein the printing layer accounts for 10-35% of the total thickness of the thinned high-rigidity label film, the core layer accounts for 30-65% of the total thickness of the thinned high-rigidity label film, and the inner layer accounts for 10-35% of the total thickness of the thinned high-rigidity label film.

[0013] The described thinned high-rigidity label film, wherein the total thickness of the thinned high-rigidity label film is 70-80 μm.

[0014] The described thinned high-rigidity label film, wherein the density of the first polyethylene is 0.94-0.97 g / cm 3 , and the melt index is 5-9 g / 10 min.

[0015] The described thinned high-rigidity label film, wherein the density of the second polyethylene is 0.92-0.935 g / cm 3 , and the melt index is 1.5-4.0 g / 10 min.

[0016] Beneficial effects: The thinned high-rigidity label film provided by the present invention is composed of three layers: a printing layer, a core layer, and an inner layer. The materials of these three layers all contain high-density first polyethylene, which has a high crystallinity, excellent rigidity and hardness properties, can reduce the thickness of the prepared label film by 10%, and can maintain good stiffness performance; in the present invention, high-density and low-density polyethylene are selected for blending in each layer. On the one hand, the prepared label film ensures its good stiffness performance and appearance flatness, which is beneficial to fine printing patterns; on the other hand, it ensures that the film has good toughness and curling properties, and can adapt to the running of different equipment. Specific embodiments

[0017] The present invention provides a thinned high-rigidity label film. To make the objectives, technical solutions and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The present invention provides a thinned high-rigidity label film. Among them, the thinned high-rigidity label film includes an inner layer, a core layer and a printing layer which are sequentially stacked from bottom to top. Among them, the inner layer includes 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight percentage; the core layer includes 15-80% of one or two of the second polyethylene and a third polyethylene, and 30-60% of the first polyethylene by weight percentage; the printing layer includes 25-55% of the first polyethylene and 40-70% of the second polyethylene by weight percentage; the first polyethylene is a high-density polyethylene with a melt index ≥ 5.0 g / 10 min and a melting point ≥ 120 °C; the second polyethylene is a low-density polyethylene with a melt index ≤ 4.0 g / 10 min and a melting point ≥ 100 °C; the melt index of the third polyethylene is 0.5-3.0 g / 10 min and the melting point ≥ 100 °C.

[0019] The thinned high-rigidity label film provided by the present invention is formed by a blown film method. It is composed of three layers: a printing layer, a core layer and an inner layer. Among them, the core layer provides the main skeleton structure, the printing layer provides a good printing effect, and the inner layer provides unrolling performance. In the present invention, by designing the raw materials of the three layers of the printing layer, the core layer and the inner layer, the materials of these three layers all contain a high density of the first polyethylene, which has a high crystallinity, excellent rigidity and hardness properties, and can reduce the thickness of the obtained label film by 10%, and can maintain good stiffness performance; in the present invention, high-density and low-density polyethylene are selected for blending in each layer. On the one hand, the obtained label film ensures its good stiffness performance and appearance flatness, which is beneficial to fine printing patterns; on the other hand, it ensures that the film has good toughness and curling performance and can adapt to the running of different equipment.

[0020] In some embodiments, the core layer further includes 5-25% of a fourth polyethylene by weight percentage. The melt index of the fourth polyethylene is 0.1-2.5 g / 10 min and the melting point ≥ 105 °C. In this embodiment, the fourth polyethylene is added when preparing a label film with a milky white appearance, and its white effective component is 40-80%.

[0021] In some embodiments, the printing layer further comprises 1-5% of a fifth polyethylene by weight percentage, and the melt index of the fifth polyethylene is 0.1-3.0 g / 10 min. In this embodiment, the fifth polyethylene is prepared by blending and modifying polyethylene with inorganic particles, and the fifth polyethylene has good dispersibility, increasing the stiffness of the label film while having good anti-blocking and unwinding properties.

[0022] In some embodiments, the inorganic particles are one or more of natural silica, natural diatomaceous stone, synthetic silica, and synthetic glass beads, but are not limited thereto.

[0023] In some embodiments, the total thickness of the thinned high-stiffness label film is 70-80 μm. Among them, the printing layer accounts for 10-35% of the total thickness of the thinned high-stiffness label film, the core layer accounts for 30-65% of the total thickness of the thinned high-stiffness label film, and the inner layer accounts for 10-35% of the total thickness of the thinned high-stiffness label film. In the present invention, high-density and low-density polyethylene are selected for blending in each layer, and the prepared label film not only ensures its good stiffness performance and appearance flatness, but also can reduce the thickness of the prepared label film by 10%.

[0024] In some embodiments, the density of the first polyethylene is 0.94-0.97 g / cm 3 , and the melt index is 5-9 g / 10 min. The density of the second polyethylene is 0.92-0.935 g / cm 3 , and the melt index is 1.5-4.0 g / 10 min.

[0025] The present invention will be further explained and illustrated by specific examples as follows:

[0026] Example 1

[0027] A label film with a thickness of 70 μm is produced by a three-layer co-extrusion blown film process, and the following formula is used for production:

[0028] 1. Printing layer with a layer thickness of 20%: The content of the first polyethylene is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the content of the second polyethylene is 70%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0029] 2. Core layer with a layer thickness of 60%: The content of the first polyethylene is 40%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the content of the second polyethylene is 60%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0030] 3. Inner layer with 20% layer thickness: The first polyethylene content is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 68%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 2.0%.

[0031] Example 2

[0032] A label film with a thickness of 78 μm is produced by a three-layer co-extrusion blown film process and is produced using the following formula:

[0033] 1. Printing layer with 25% layer thickness: The first polyethylene content is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 70%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0034] 2. Core layer with 50% layer thickness: The first polyethylene content is 40%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 60%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0035] 3. Inner layer with 25% layer thickness: The first polyethylene content is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 67%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 3.0%.

[0036] Example 3

[0037] A label film with a thickness of 72 μm is produced by a three-layer co-extrusion blown film process and is produced using the following formula:

[0038] 1. Printing layer with 25% layer thickness: The first polyethylene content is 40%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 60%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0039] 2. Core layer with 50% layer thickness: The first polyethylene content is 45%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 55%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0040] 3. Inner layer with 25% layer thickness: The first polyethylene content is 40%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 58%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 2.0%.

[0041] Example 4

[0042] The label film with a thickness of 72 μm is produced by a three-layer co-extrusion blown film process and is produced using the following formula:

[0043] 1. Printing layer with a layer thickness of 25%: The first polyethylene content is 40%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 60%, the melting point is ≥110 °C, and the melt index is 4.0 g / 10 min;

[0044] 2. Core layer with a layer thickness of 50%: The first polyethylene content is 45%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 35%, the melting point is ≥110 °C, and the melt index is 4.0 g / 10 min; the content of white masterbatch particles is 20%.

[0045] 3. Inner layer with a layer thickness of 25%: The first polyethylene content is 40%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 58%, the melting point is ≥110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 2.0%.

[0046] Example 5

[0047] The label film with a thickness of 70 μm is produced by a three-layer co-extrusion blown film process and is produced using the following formula:

[0048] 1. Printing layer with a layer thickness of 20%: The first polyethylene content is 30%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 70%, the melting point is ≥110 °C, and the melt index is 4.0 g / 10 min;

[0049] 2. Core layer with a layer thickness of 60%: The first polyethylene content is 40%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the third polyethylene content is 50%, the melting point is ≥100 °C, and the melt index is 3.0 g / 10 min; the fourth polyethylene content is 10%, the melting point is ≥110 °C, and the melt index is 2.5 g / 10 min;

[0050] 3. Inner layer with a layer thickness of 20%: The first polyethylene content is 30%, the melting point is ≥130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 65%, the melting point is ≥110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 5.0%.

[0051] Example 6

[0052] The label film with a thickness of 70 μm is produced by a three-layer co-extrusion blown film process and is produced using the following formula:

[0053] 1. Printing layer with a thickness of 20%: The first polyethylene content is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 70%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min;

[0054] 2. Core layer with a thickness of 60%: The first polyethylene content is 40%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 30%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min; the third polyethylene content is 20%, the melting point ≥ 100 °C, and the melt index is 2.0 g / 10 min; the fourth polyethylene content is 10%, the melting point ≥ 110 °C, and the melt index is 1.5 g / 10 min;

[0055] 3. Inner layer with a thickness of 20%: The first polyethylene content is 30%, the melting point ≥ 130 °C, and the melt index is 5.5 g / 10 min; the second polyethylene content is 67%, the melting point ≥ 110 °C, and the melt index is 4.0 g / 10 min; the fifth polyethylene content is 3.0%.

[0056] Test example

[0057] The stiffness and dynamic friction coefficient of the label films prepared in Examples 1 - 6 were tested, and the results are shown in Table 1:

[0058] Table 1 Test results

[0059]

[0060] It can be seen from the data in Table 1 that by blending different types of polyethylene in the present invention, the comprehensive performance of the prepared label film with reduced thickness, good stiffness, and moderate friction coefficient can be achieved.

[0061] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A thinned high-rigidity label film, characterized in that, The thinned high-rigidity label film comprises an inner layer, a core layer and a printing layer which are sequentially stacked from bottom to top. Among them, the inner layer comprises 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight percentage; the core layer comprises 15-80% of a second polyethylene and a third polyethylene, and 30-60% of a first polyethylene by weight percentage; the printing layer comprises 25-55% of a first polyethylene and 40-70% of a second polyethylene by weight percentage; the first polyethylene is a high-density polyethylene with a melt index of 5-9 g / 10 min, a melting point ≥ 120 °C, and a density of 0.94-0.97 g / cm 3 ; the second polyethylene is a low-density polyethylene with a melt index of 1.5-4.0 g / 10 min, a melting point ≥ 100 °C, and a density of 0.92-0.935 g / cm 3 ; the melt index of the third polyethylene is 0.5-3.0 g / 10 min, and the melting point ≥ 100 °C; the core layer further comprises 5-25% of a fourth polyethylene by weight percentage, the melt index of the fourth polyethylene is 0.1-2.5 g / 10 min, and the melting point ≥ 105 °C; the printing layer further comprises 1-5% of a fifth polyethylene by weight percentage, and the melt index of the fifth polyethylene is 0.1-3.0 g / 10 min; the total thickness of the thinned high-rigidity label film is 70-80 μm; the printing layer accounts for 10-35% of the total thickness of the thinned high-rigidity label film, the core layer accounts for 30-65% of the total thickness of the thinned high-rigidity label film, and the inner layer accounts for 10-35% of the total thickness of the thinned high-rigidity label film.

2. The thinned high-rigidity label film according to claim 1, wherein The fifth polyethylene is prepared by blending and modifying polyethylene with inorganic particles.

3. The thinned high-rigidity label film according to claim 2, wherein The inorganic particles are one or more of natural silica, natural diatomaceous stone, synthetic silica, and synthetic glass microspheres.

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