Frosted direct-plating paper label as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of labels, and discloses a frosted direct-plating paper label and a preparation method and application thereof. The frosted direct plating paper label sequentially comprises a gloss oil layer, an ink layer, a surface coating, an anti-counterfeiting aluminum plating layer, a frosted coating, a body paper layer and a back coating from top to bottom, the raw materials of the frosted coating comprise a water-based acrylic emulsion and sand flour; the raw paper layer is made of wet-strength paper, and the wet tensile strength of the wet-strength paper is larger than or equal to 9 N / 15 mm. The frosted direct-plating paper label is easy to elute, the label removal time is less than or equal to 3 minutes, the ink retention rate is more than or equal to 80 percent, and meanwhile, the frosted direct-plating paper label has excellent wear resistance and labeling performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of labels, and in particular relates to a frosted direct-plated paper label and a preparation method and application thereof. Background Art

[0002] With the continuous development of the industry, the requirements for label materials are getting higher and higher. Although traditional aluminized paper labels have good metallic luster and barrier properties, the aluminum grain on the surface is smooth and lacks unique texture. In order to meet the market demand for label materials with special visual and tactile effects, frosted direct-plated aluminized paper came into being.

[0003] Frosted direct-plated aluminized paper not only has the basic properties of aluminized paper, but also has a delicate frosted texture on its surface through special process treatment, which increases the beauty and uniqueness of the label. However, the frosted direct-plated aluminized paper technology on the market still has some shortcomings. Its production process is roughly as follows: primer → aluminizing → top coating → back coating → reverse UV printing. It obtains a frosted effect through reverse UV printing. After the labels made by reverse UV printing are labeled on beer bottles, they need to be delabeled during the subsequent recycling and reuse of the bottles. The labels are difficult to wash off (the delabeling time is greater than 3 minutes), and the ink basically does not remain on the labels, causing pollution. Recycling is difficult, which limits its further promotion and application.

[0004] Therefore, it is necessary to develop a frosted direct-plated paper label that is easy to remove. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a frosted direct-plated paper label and a preparation method and application thereof, wherein the frosted direct-plated paper label is easy to wash off, the label removal time is ≤3min, and the ink retention rate is ≥80%.

[0006] The first aspect of the present invention provides a frosted direct-plated paper label, which includes, from top to bottom, a varnish layer, an ink layer, a top coating layer, an anti-counterfeiting aluminum-plated layer, a frosted coating layer, a base paper layer and a back coating layer; the raw materials of the frosted coating layer include water-based acrylic emulsion and sand powder; the base paper layer adopts wet-strength paper, and the wet tensile strength of the wet-strength paper is ≥9N / 15mm.

[0007] Specifically, the sand powder used in the present invention has the characteristics of UV resistance, light resistance, heat resistance, acid and alkali resistance, good compatibility with water-based acrylic emulsion, can be better and more evenly distributed in the matte coating, has a unique matte texture and visual effect, is not easy to fall off or peel off, and helps to ensure the quality and durability of the matte coating.

[0008] Specifically, the wet tensile strength of the wet-strength paper used in the present invention is ≥9N / 15mm. If the wet tensile strength is too low, the paper may break easily during processing, and the performance requirements of the direct-plated frosted paper label cannot be met.

[0009] In some embodiments of the present invention, the wet-strength paper has a transverse wet tensile strength of ≥9N / 15mm.

[0010] In some embodiments of the present invention, the longitudinal wet tensile strength of the wet-strength paper is ≥12N / 15mm.

[0011] In some embodiments of the present invention, the solid content of the aqueous acrylic emulsion is 25±3%.

[0012] In some embodiments of the present invention, the coating-4 cup viscosity of the aqueous acrylic emulsion is 24±2s.

[0013] In some embodiments of the present invention, the particle size of the sand flour is 30-60 μm.

[0014] In some embodiments of the present invention, the particle size of the sand flour is 35-55 μm.

[0015] Specifically, if the particle size of the sand flour in the present invention is greater than 60 μm, the compatibility of the aqueous acrylic emulsion is poor, and the sand flour is prone to stratification and sinking to the bottom; if the particle size is less than 30 μm, the frosting effect is not obvious enough, and the unique texture and visual effect of frosted aluminum-plated paper cannot be fully demonstrated. Therefore, the present invention selects sand flour with a particle size in a suitable range.

[0016] In some embodiments of the present invention, the density of the sand flour is 0.5-2 g / cm 3 .

[0017] In some embodiments of the present invention, the density of the sand flour is 0.5-1.5 g / cm 3 .

[0018] In some embodiments of the present invention, the melting point of the sand flour is 200-400°C.

[0019] In some embodiments of the present invention, the melting point of the sand flour is 200-300°C.

[0020] In some embodiments of the present invention, the mass of the sand flour is 2-5% of the mass of the aqueous acrylic emulsion.

[0021] Specifically, if the mass proportion of the sand powder in the present invention is greater than 5%, the material will become too stiff, which will cause difficulties in post-processing cutting and punching and label warping; if the mass proportion is less than 2%, the frosting effect of the coating will be insufficiently uniform, the frosting feeling will not be obvious, and the product performance will be affected.

[0022] In some embodiments of the present invention, the basis weight of the wet strength paper is 45-75 g / m 2 ; and / or, the moisture content of the wet-strength paper is 4.5±0.5%; and / or, the water curling time of the wet-strength paper is ≥15s; and / or, the smoothness of the front side of the wet-strength paper is ≥900s; and / or, the Cobb60 value of the back side of the wet-strength paper is 17±3g / m 2 .

[0023] In some embodiments of the present invention, the thickness of the anti-counterfeiting aluminum coating is

[0024] Specifically, the thickness of the anti-counterfeiting aluminum-plated layer of the present invention should not be too thick. The visibility of the image and text under natural light can be controlled by adjusting the thickness of the anti-counterfeiting aluminum-plated layer. It has high recognition accuracy with the naked eye, can enhance the brightness of the product’s metallic luster, and provide anti-counterfeiting protection for the product.

[0025] The second aspect of the present invention provides a method for preparing the frosted direct-plated paper label according to the first aspect of the present invention, comprising the following steps:

[0026] S1, mixing the aqueous acrylic emulsion and sand flour, stirring to obtain a mixed emulsion;

[0027] S2, coating the mixed emulsion on the upper surface of the wet-strength paper, and drying to form a frosted coating;

[0028] S3, vacuum aluminum plating is performed on the upper surface of the frosted coating to form an anti-counterfeiting aluminum plating layer;

[0029] S4, respectively performing top coating, back coating, printing ink and coating varnish to form a top coating layer, a back coating layer, an ink layer and a varnish layer to obtain the frosted direct-plated paper label.

[0030] In some embodiments of the present invention, in step S2, the dry weight of the coating is 1-3 g / m 2 ; and / or, the coating speed is 120-150m / min.

[0031] In some embodiments of the present invention, in step S2, the drying temperature is 70-120°C.

[0032] Specifically, the transverse shrinkage of the paper after step S2 is ≤3mm, and the moisture content of the paper is 2.5-3.5%. If the moisture content of the paper is too high, it will affect the processing quality of the next step of vacuum aluminum plating, such as yellowing, coloring, uneven aluminum plating, etc.

[0033] In some embodiments of the present invention, in step S4, the top coating has a solid content of 18-25% and a coating dry weight of 0.8-1.5 g / m 2 Water-based acrylic resin.

[0034] Specifically, after the surface coating treatment, the transverse shrinkage of the paper is ≤1mm, the moisture content of the paper is 2.5-3.5%, and the abrasion resistance times are ≥70 times.

[0035] Specifically, vacuum aluminum plating: use an aluminum plating machine to aluminum-plate special edition text. The principle is to simulate the gravure printing principle. Use a template with special anti-counterfeiting text to print shielding oil onto paper. This printing device is installed on the aluminum plating machine, and then vacuum aluminum plating is carried out. The position of the image and text printed with shielding oil will not be attached to the aluminum layer and the image and text effect will be shown.

[0036] In some embodiments of the present invention, the specific process of step S4 is:

[0037] Performing top coating on the upper surface of the anti-counterfeiting aluminum-plated layer to form a top coating layer;

[0038] Performing back coating on the lower surface of the wet-strength paper to form a back coating layer;

[0039] The upper surface of the top coating layer is printed with ink and coated with varnish in sequence to form an ink layer and a varnish layer in sequence, thereby obtaining the frosted direct-plated paper label.

[0040] In some embodiments of the present invention, the printing is conventional offset printing.

[0041] In some embodiments of the present invention, after forming the back coating layer, the back coating layer is further subjected to a water vapor rehumidification treatment.

[0042] The third aspect of the present invention provides application of the frosted direct-plated paper label described in the first aspect of the present invention in a glass bottle label.

[0043] Specifically, the frosted direct-plated paper label described in the first aspect of the present invention is used in a beer bottle label.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] 1) The frosted direct-plated paper label of the present invention has the characteristics of easy washing, the label removal time is ≤3min, and the ink retention rate is ≥80%, which can solve the problems of difficult label removal and ink pollution in the existing reverse UV printing. The label has the environmental protection performance of being degradable and recyclable, reducing environmental pollution.

[0046] 2) The present invention improves the wear resistance of the frosted direct-plated paper label by combining wet-strength paper and sandpaper powder, increasing the wear resistance of the existing label from about 50 times to more than 70 times.

[0047] 3) The frosted direct-plated paper label of the present invention has excellent labeling performance. While maintaining the frosted metallic luster, the frosted direct-plated paper label also inherits the flexibility and environmental adaptability of the base paper. The flatness of the label can always be maintained at -6mm~+2mm in an environment with a humidity of 30-80%. The curling time of the label when exposed to water is ≥20 seconds, and the moisture content of the label is 3.5-4.5%, so that the label and the glass bottle have better adhesion performance during the labeling process, which solves the problem of bubbling easily generated by the existing frosted label. The frosted label can also be labeled at a high speed, and the labeling speed can reach 48,000 bottles / h, which meets the application requirements of frosted labels in wet glue labeling of wine packaging, and realizes environmentally friendly washable labels and recyclable bottles for reuse.

[0048] 4) The anti-counterfeiting aluminum-plated layer of the frosted direct-plated paper label of the present invention improves the anti-counterfeiting performance of the label, thereby effectively preventing the emergence of counterfeit products. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the structure of a frosted direct-plated paper label according to an embodiment of the present invention.

[0050] Reference numerals: 100, varnish layer; 200, ink layer; 300, top coating layer; 400, anti-counterfeiting aluminum-plated layer; 500, frosted coating layer; 600, base paper layer; 700, back coating layer. DETAILED DESCRIPTION

[0051] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0052] Unless otherwise specified, the raw materials, reagents or devices used in the present invention can be obtained from conventional commercial channels or by existing known methods.

[0053] Example 1

[0054] refer to Figure 1As shown, a frosted direct-plated paper label includes, from top to bottom, a varnish layer 100, an ink layer 200, a top coating layer 300, an anti-counterfeiting aluminum-plated layer 400, a frosted coating layer 500, a base paper layer 600 and a back coating layer 700;

[0055] The raw materials of the frosted coating include water-based acrylic emulsion and sand flour; the solid content of the water-based acrylic emulsion is 25±3%, and the coating-4 cup viscosity is 24±2s; the particle size of the sand flour is 45μm and the density is 0.96g / cm 3 , melting point is 230℃;

[0056] The base paper layer is 60g / m 2 The wet-strength paper has a moisture content of 4.5±0.5%, a transverse wet tensile strength of 9N / 15mm, a longitudinal wet tensile strength of 12N / 15mm, a water curling time of 15s, a front smoothness of 900s, and a back Cobb60 value of 17±3g / m 2 .

[0057] The preparation method of the frosted direct-plated paper label in this example is:

[0058] S1, mixing the aqueous acrylic emulsion and sand flour, stirring and dispersing them evenly to obtain a mixed emulsion; wherein the mass of the sand flour is 3% of the mass of the aqueous acrylic emulsion;

[0059] S2, coating the mixed emulsion on the upper surface of the wet-strength paper, and drying at 100°C to form a frosted coating; wherein the dry coating weight is 2g / m 2 , the coating speed is 130m / min;

[0060] S3, vacuum aluminum is plated on the upper surface of the frosted coating by an aluminum plating machine to form a Anti-counterfeiting aluminum coating;

[0061] S4, using a water-based acrylic resin with a solid content of 20% to coat the upper surface of the anti-counterfeiting aluminum coating, and drying at 80°C to form a top coating; wherein the coating dry weight is 1.2g / m 2 , the coating speed is 130m / min;

[0062] S5. Performing conventional back coating on the lower surface of the wet-strength paper to form a back coating layer;

[0063] S6. Conventional offset printing ink and varnish coating are sequentially performed on the upper surface of the top coating layer to form an ink layer and a varnish layer in sequence, thereby obtaining a frosted direct-plated paper label.

[0064] Example 2

[0065] A frosted direct-plated paper label, which includes, from top to bottom, a varnish layer, an ink layer, a top coating layer, an anti-counterfeiting aluminum-plated layer, a frosted coating layer, a base paper layer and a back coating layer;

[0066] The raw materials of the frosted coating include water-based acrylic emulsion and sand flour; the solid content of the water-based acrylic emulsion is 25±3%, and the coating-4 cup viscosity is 24±2s; the particle size of the sand flour is 40μm and the density is 0.96g / cm 3 , melting point is 230℃;

[0067] The base paper layer is 45g / m 2 The wet-strength paper has a moisture content of 4.5±0.5%, a transverse wet tensile strength of 9N / 15mm, a longitudinal wet tensile strength of 12N / 15mm, a water curling time of 15s, a front smoothness of 900s, and a back Cobb60 value of 17±3g / m 2 .

[0068] The preparation method of the frosted direct-plated paper label in this example is:

[0069] S1, mixing the aqueous acrylic emulsion and sand flour, stirring and dispersing them evenly to obtain a mixed emulsion; wherein the mass of the sand flour is 2% of the mass of the aqueous acrylic emulsion;

[0070] S2, coating the mixed emulsion on the upper surface of the wet-strength paper, and drying at 100°C to form a frosted coating; wherein the dry coating weight is 1g / m 2 , the coating speed is 120m / min;

[0071] S3, vacuum aluminum is plated on the upper surface of the frosted coating by an aluminum plating machine to form a Anti-counterfeiting aluminum coating;

[0072] S4, using a water-based acrylic resin with a solid content of 18% to coat the upper surface of the anti-counterfeiting aluminum coating, and drying at 70°C to form a top coating; wherein the coating dry weight is 0.8g / m 2 , the coating speed is 120m / min;

[0073] S5. Performing conventional back coating on the lower surface of the wet-strength paper to form a back coating layer;

[0074] S6. Conventional offset printing ink and varnish coating are sequentially performed on the upper surface of the top coating layer to form an ink layer and a varnish layer in sequence, thereby obtaining a frosted direct-plated paper label.

[0075] Example 3

[0076] A frosted direct-plated paper label, which includes, from top to bottom, a varnish layer, an ink layer, a top coating layer, an anti-counterfeiting aluminum-plated layer, a frosted coating layer, a base paper layer and a back coating layer;

[0077] The raw materials of the frosted coating include water-based acrylic emulsion and sand flour; the solid content of the water-based acrylic emulsion is 25±3%, and the coating-4 cup viscosity is 24±2s; the particle size of the sand flour is 50μm and the density is 0.96g / cm 3 , melting point is 230℃;

[0078] The base paper layer is 75g / m 2 The wet-strength paper has a moisture content of 4.5±0.5%, a transverse wet tensile strength of 9N / 15mm, a longitudinal wet tensile strength of 12N / 15mm, a water curling time of 15s, a front smoothness of 900s, and a back Cobb60 value of 17±3g / m 2 .

[0079] The preparation method of the frosted direct-plated paper label in this example is:

[0080] S1, mixing the aqueous acrylic emulsion and sand flour, stirring and dispersing them evenly to obtain a mixed emulsion; wherein the mass of the sand flour is 5% of the mass of the aqueous acrylic emulsion;

[0081] S2, coating the mixed emulsion on the upper surface of the wet-strength paper, and drying at 100°C to form a frosted coating; wherein the dry coating weight is 5g / m 2 , the coating speed is 150m / min;

[0082] S3, vacuum aluminum is plated on the upper surface of the frosted coating by an aluminum plating machine to form a Anti-counterfeiting aluminum coating;

[0083] S4, using a water-based acrylic resin with a solid content of 25% to coat the upper surface of the anti-counterfeiting aluminum coating, and drying at 80°C to form a top coating; wherein the coating dry weight is 1.5g / m 2 , the coating speed is 150m / min;

[0084] S5. Performing conventional back coating on the lower surface of the wet-strength paper to form a back coating layer;

[0085] S6. Conventional offset printing ink and varnish coating are sequentially performed on the upper surface of the top coating layer to form an ink layer and a varnish layer in sequence, thereby obtaining a frosted direct-plated paper label.

[0086] Label performance test

[0087] With reference to the industry standard for vacuum aluminum-plated paper (BB / T 0054-2010), the moisture content of the frosted direct-plated paper labels prepared in Examples 1-3 of the present invention is 3.5-4.5%, the flatness is -6mm to +2mm at a humidity of 30-80%, the curling time when exposed to water is ≥20s, and the wear resistance is ≥70 times; after the frosted direct-plated paper labels prepared in Examples 1-3 of the present invention are used to label beer bottles, when the recycled beer bottles are de-labeled, the de-labeling time is ≤3min, and the ink retention rate is ≥80%.

[0088] The preferred embodiments of the present invention are specifically described above, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A frosted direct-plated paper label, characterized in that: From top to bottom, it includes a varnish layer, an ink layer, a top coating layer, an anti-counterfeiting aluminum-plated layer, a frosted coating layer, a base paper layer and a back coating layer; the raw materials of the frosted coating layer include water-based acrylic emulsion and sand powder; the base paper layer is made of wet-strength paper, and the wet tensile strength of the wet-strength paper is ≥9N / 15mm.

2. The frosted direct-plated paper label according to claim 1, characterized in that: The solid content of the aqueous acrylic emulsion is 25±3%; and / or the coating-4 cup viscosity of the aqueous acrylic emulsion is 24±2s.

3. The frosted direct-plated paper label according to claim 1, characterized in that: The particle size of the sand flour is 30-60 μm.

4. The frosted direct-plated paper label according to claim 1, characterized in that: The mass of the sand flour is 2-5% of the mass of the aqueous acrylic emulsion.

5. The frosted direct-plated paper label according to claim 1, characterized in that: The basis weight of the wet strength paper is 45-75 g / m 2 ; and / or, the moisture content of the wet-strength paper is 4.5±0.5%; and / or, the water curling time of the wet-strength paper is ≥15s; and / or, the smoothness of the front side of the wet-strength paper is ≥900s; and / or, the Cobb60 value of the back side of the wet-strength paper is 17±3g / m 2 .

6. The frosted direct-plated paper label according to claim 1, characterized in that: The thickness of the anti-counterfeiting aluminum plating layer is 7. The method for preparing a frosted direct-plated paper label according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, mixing the aqueous acrylic emulsion and sand flour, stirring to obtain a mixed emulsion; S2, coating the mixed emulsion on the upper surface of the wet-strength paper, and drying to form a frosted coating; S3, vacuum aluminum plating is performed on the upper surface of the frosted coating to form an anti-counterfeiting aluminum plating layer; S4, respectively performing top coating, back coating, printing ink and coating varnish to form a top coating layer, a back coating layer, an ink layer and a varnish layer to obtain the frosted direct-plated paper label.

8. The preparation method according to claim 7, characterized in that: In step S2, the dry weight of the coating is 1-3 g / m 2 ; and / or, the coating speed is 120-150m / min.

9. The preparation method according to claim 7, characterized in that: In step S4, the top coating has a solid content of 18-25% and a coating dry weight of 0.8-1.5 g / m 2 Water-based acrylic resin.

10. Application of the frosted direct-plated paper label according to any one of claims 1 to 6 in glass bottle labels.

Images