A type of laminated thermal label paper

Abstract

This utility model relates to the field of label material technology, and more particularly to a laminated thermal label paper, comprising a base layer, a thermal color developing layer, a temperature-sensitive indicator layer, and a laminating layer; the base layer has intermittent easy-tear lines at its edge, the easy-tear lines being composed of alternating perforated segments and connecting segments. This utility model, by embedding reversible color-changing material into the gaps between the protrusions of the thermal color developing layer, enables the label to provide intuitive feedback on ambient temperature, breaking through the limitations of traditional labels that can only achieve basic identification, effectively expanding to temperature-sensitive application scenarios such as fresh produce and pharmaceuticals; simultaneously, the use of a convex-concave interlocking microstructure design achieves adhesive-free bonding between the laminating layer and the thermal color developing layer, replacing traditional adhesive bonding methods, avoiding interlayer delamination problems, eliminating pollution caused by adhesive residue, and providing better bonding strength.

Description

Technical Field

[0001] This utility model relates to the field of label material technology, and in particular to a laminated thermal label paper. Background Technology

[0002] Laminated thermal label paper is a high-performance label material formed by laminating a layer of transparent plastic film (such as polyester PET or polypropylene PP) onto the surface of traditional thermal label paper. It combines the convenience of thermal printing with the multiple protective functions provided by lamination. Its core structure typically includes a backing paper, a silicone oil layer, a substrate layer, a thermal color developing layer, a polyester film layer, and a release matte varnish layer. The film and paper layers are permanently bonded together through a hot-pressing process, forming a paper-plastic integrated product. Existing laminated thermal label paper has significant limitations in function and structure: First, its function is relatively simple, only able to achieve static information marking through thermal color development, and cannot respond to temperature changes in the application environment. In temperature-sensitive scenarios such as fresh food cold chain and pharmaceutical transportation, additional temperature monitoring equipment is required, increasing the cost and complexity of use. Second, interlayer bonding generally relies on adhesives, which are prone to aging and failure under long-term use or changes in environmental temperature and humidity, leading to delamination between the laminate and the base layer, affecting the integrity of the label. At the same time, adhesive residue on discarded labels causes environmental pollution, which does not meet environmental protection requirements. Furthermore, the strength of traditional adhesive bonding methods is limited by material compatibility, making it difficult to meet the needs of high-stability scenarios. Utility Model Content

[0003] The purpose of this invention is to provide a laminated thermal label paper that solves the problems of existing laminated thermal label papers, such as limited functionality, inability to respond to changes in ambient temperature, reliance on adhesives for interlayer bonding leading to delamination, adhesive residue pollution, and insufficient bonding strength.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A laminated thermal label paper includes a base layer, a thermal color developing layer, a temperature-sensitive indicator layer, and a laminating layer; the base layer has intermittent easy-tear lines at its edges, the easy-tear lines being composed of alternating perforated segments and connecting segments; the surface of the thermal color developing layer is distributed with a micron-sized array of raised dots; the temperature-sensitive indicator layer is a reversible color-changing coating that covers the gaps between the raised dots in the thermal color developing layer; the inner side of the laminating layer has a recessed structure matching the raised dot array, achieving adhesive-free bonding with the thermal color developing layer through convex-concave interlocking.

[0005] Preferably, the perforated section of the intermittent easy-tear line has a length of 1-2 mm, the connecting section has a length of 0.3-0.5 mm, and the spacing between adjacent easy-tear lines is 5-8 mm, forming a tearable path that can be torn by hand.

[0006] Preferably, the micron-scale bump array of the thermosensitive color-developing layer is made of thermosetting resin.

[0007] Preferably, the temperature-sensitive indicator layer is made of a spiropyran-based color-changing material.

[0008] Preferably, the coating layer is a starch-based composite film.

[0009] Preferably, the base layer is a modified paper material containing bamboo fiber.

[0010] Preferably, the thermosensitive color-developing layer contains a leuco dye modified with nano-silica.

[0011] Preferably, the outer side of the coating layer has an anti-glare texture.

[0012] This utility model has at least the following beneficial effects: By embedding reversible color-changing material into the gaps between the raised dots of the thermosensitive color-developing layer, the label has an intuitive feedback function for ambient temperature, breaking through the limitation of traditional labels that can only achieve basic identification, and effectively expanding to temperature-sensitive application scenarios such as fresh produce and pharmaceuticals; at the same time, the microstructure design of the raised and recessed interlocking achieves glue-free bonding between the film layer and the thermosensitive color-developing layer, replacing the traditional adhesive bonding method, which not only avoids the problem of interlayer delamination, but also eliminates the pollution caused by adhesive residue, and has better bonding strength. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the intermittent tear-off line structure of this utility model; Figure 3 This is a schematic diagram of the thermal color development layer structure of this utility model; Figure 4 This is a schematic diagram of the coating layer structure of this utility model.

[0015] In the diagram: 1. Base layer; 2. Thermosensitive color developing layer; 3. Temperature-sensitive indicator layer; 4. Coating layer; 5. Intermittent easy-tear lines; 6. Raised dot array; 7. Dent structure. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] Reference Figure 1-4 A laminated thermal label paper includes a base layer 1, a thermal color developing layer 2, a temperature-sensitive indicator layer 3, and a laminating layer 4. The base layer 1 has intermittent easy-tear lines 5 at its edges, which are composed of alternating perforated segments and connecting segments. The surface of the thermal color developing layer 2 is distributed with a raised dot array 6. The temperature-sensitive indicator layer 3 is a reversible color-changing coating that covers the gaps between the raised dot array 6 of the thermal color developing layer 2. The inner side of the laminating layer 4 has a recessed structure 7 that matches the raised dot array 6, achieving adhesive-free bonding with the thermal color developing layer 2 through convex-concave interlocking.

[0019] Furthermore, the perforated section of the easy-tear line 5 has a length of 1-2 mm, the connecting section has a length of 0.3-0.5 mm, and the spacing between adjacent easy-tear lines 5 is 5-8 mm, forming a tearable path that can be torn by hand. After testing, its tearing force is ≤5N, and the test method refers to GB / T2792-2014.

[0020] Furthermore, the bump array 6 of the thermosensitive color development layer 2 is made of thermosetting resin and prepared by hot pressing molding process. The bonding strength with the base layer 1 is ≥2N / cm, the bump height is 5-10μm, the diameter is 20-30μm, and the spacing between adjacent bumps is 50-80μm.

[0021] Furthermore, the temperature-sensitive indicator layer 3 is made of spiropyran-based color-changing material, which is coated by screen printing process, covering only the gaps between the protrusions. It appears blue in the range of 10-30℃, turns pink below 10℃, and becomes colorless above 30℃.

[0022] Furthermore, the coating layer 4 is a starch-based composite film, which is glue-free bonded by a roll pressing process, with the pressure controlled at 0.5-1MPa, the peel strength ≥3N / cm, the thickness 8-15μm, and the degree of fit between the inner pit structure 7 and the protrusions of the thermosensitive color development layer 2 ≥90%.

[0023] Furthermore, the base layer 1 is a modified paper material containing bamboo fiber, with a bamboo fiber content of 30%-40%, a transverse tensile strength of 20-30 MPa, and a longitudinal tensile strength of 40-50 MPa. Furthermore, the thermosensitive color-developing layer 2 contains a leuco dye modified with nano-silica, with the nano-silica accounting for 5%-8% of the mass, which improves the lightfastness after color development.

[0024] Furthermore, the outer side of the coating layer 4 is provided with an anti-glare texture with a texture depth of 1-2μm and a light transmittance of more than 85%. The light transmittance test standard refers to ASTM D1003.

[0025] In summary, by embedding the reversible color-changing material into the gaps between the raised dots of the thermosensitive color-developing layer 2, the label has an intuitive feedback function for ambient temperature, breaking through the limitation of traditional labels that can only achieve basic identification, and effectively expanding to application scenarios that are sensitive to temperature, such as fresh produce and pharmaceuticals. At the same time, the use of a raised-and-concave interlocking microstructure design enables adhesive-free bonding between the coating layer 4 and the thermosensitive color-developing layer 2, replacing the traditional adhesive bonding method. This avoids the problem of interlayer delamination, eliminates the pollution caused by adhesive residue, and provides better bonding strength.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A film-coated heat-sensitive label paper, characterized in that It includes a base layer, a thermosensitive color developing layer, a temperature-sensitive indicator layer, and a coating layer; the base layer has intermittent easy-tear lines at its edges, which are composed of alternating perforated sections and connecting sections; the surface of the thermosensitive color developing layer is distributed with a raised dot array; the temperature-sensitive indicator layer is a reversible color-changing coating that covers the gaps between the raised dots of the thermosensitive color developing layer; the inner side of the coating layer has a pit structure that matches the raised dot array, achieving adhesive-free bonding with the thermosensitive color developing layer through convex-concave interlocking.

2. The film-coated heat-sensitive label paper according to claim 1, characterized in that The perforated section of the intermittent easy-tear line has a length of 1-2mm, the connecting section has a length of 0.3-0.5mm, and the spacing between adjacent easy-tear lines is 5-8mm, forming a tearable path that can be torn by hand.

3. The film-coated heat-sensitive label paper according to claim 1, characterized in that, The bump array of the thermosensitive color developing layer is made of thermosetting resin.

4. The film-coated heat-sensitive label paper according to claim 1, wherein The temperature-sensitive indicator layer uses a spiropyran-based color-changing material.

5. The film-coated heat-sensitive label paper according to claim 1, wherein The coating layer is a starch-based composite film.

6. The film-coated heat-sensitive label paper according to claim 1, wherein The base layer is a modified paper material containing bamboo fiber.

7. The film-coated heat-sensitive label paper according to claim 1, characterized in that, The outer side of the coating layer has an anti-glare texture.

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