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CN-121999675-A - Preparation method of self-adhesive label based on gel state transfer coating

CN121999675ACN 121999675 ACN121999675 ACN 121999675ACN-121999675-A

Abstract

The application discloses a preparation method of a self-adhesive label based on gel state transfer coating, which comprises the steps of coating a hot-melt pressure-sensitive adhesive heated to a melt flow temperature on a first release carrier to form a melt adhesive layer on the surface of the first release carrier, cooling the melt adhesive layer to a gelation temperature in a gradient manner to enable the melt adhesive layer to gel from outside to inside to form a gel state adhesive film, stripping the first release carrier after the gel state adhesive film is pressed with a label surface material, transferring the gel state adhesive film on the first release carrier to the label surface material to form an adhesive surface layer on the surface of the label surface material, and compositing the adhesive surface layer with a second release carrier to obtain the self-adhesive label. The method effectively eliminates the phenomenon of glue overflow, does not need long-time high-temperature curing or preparation of the middle double-sided adhesive tape required by the traditional hot melt adhesive process, and can realize on-line continuous and efficient production from coating to finished product.

Inventors

  • Ying Gewei
  • Ying Weili

Assignees

  • 广东金麟复合新材料有限公司

Dates

Publication Date
20260508
Application Date
20260216

Claims (10)

  1. 1. The preparation method of the self-adhesive label based on gel state transfer coating is characterized by comprising the following steps of: Coating a hot-melt pressure-sensitive adhesive heated to a melt flow temperature on a first release carrier to form a melt adhesive layer on the surface of the first release carrier; Cooling the molten adhesive layer in a gradient manner to a gelation temperature to gel the molten adhesive layer from outside to inside so as to form a gel-state adhesive film; After the gel state adhesive film and the label surface material are pressed, the first release carrier is peeled off, so that the gel state adhesive film on the first release carrier is transferred to the label surface material to form a surface layer with adhesive on the surface of the label surface material; and compounding the adhesive surface layer with a second release carrier to obtain the self-adhesive label.
  2. 2. The method for preparing a self-adhesive label based on gel state transfer coating according to claim 1, wherein the step of coating the hot-melt pressure-sensitive adhesive heated to the melt flow temperature on the first release carrier to form a melt adhesive layer on the microstructure surface of the first release carrier comprises the steps of: And preheating the surface temperature of the first release carrier to 50-70 ℃ through a preheating roller, and coating a hot-melt pressure-sensitive adhesive with the temperature of 155-170 ℃ on the microstructure surface of the first release carrier to form the molten adhesive layer, wherein the coating amount is 15 g/m < 2 > -25 g/m < 2 >, and the coating pressure is 0.15-0.3 MPa.
  3. 3. The method for preparing a self-adhesive label based on gel state transfer coating according to claim 1, wherein the step of cooling the molten adhesive layer to a gelation temperature in a gradient manner to gel the molten adhesive layer from outside to inside to form a gel state adhesive film comprises: contacting the molten adhesive layer on the first release carrier with a cooling roller set for 1 s-3 s to form a gel skin by rapid cooling on the surface layer of the molten adhesive layer, wherein the surface temperature of the cooling roller set is 10-20 ℃ lower than the softening point of the hot-melt pressure-sensitive adhesive; And (3) treating the molten adhesive layer for 5 s-15 s by using circulating air at the temperature of 250-40 ℃ to gel the molten adhesive layer from the gel surface layer to the inside, and then sending the molten adhesive layer into an environment at the temperature of 30-45 ℃ to stand for 10-30 min to obtain the gel adhesive film.
  4. 4. The method for preparing the self-adhesive label based on gel state transfer coating as claimed in claim 3, wherein the surface of the main cooling roller of the cooling roller set is provided with a non-smooth microstructure, the microstructure is hemispherical microprotrusions or prismatic microprotrusions which are arranged in an array, the height of the microprotrusions is 10-50 μm, and the center-to-center distance is 100-300 μm.
  5. 5. The method for preparing a self-adhesive label based on gel state transfer coating as claimed in claim 3, wherein the step of treating the molten adhesive layer with circulating air at 25 ℃ to 40 ℃ for 5s to 15s to gel the molten adhesive layer from the gel surface layer to the inside, and then sending the gel layer into an environment at 30 ℃ to 45 ℃ for 10min to 30min to obtain a gel state adhesive film, which comprises the following steps: The molten adhesive layer is fused into a controllable convection cooling channel, at least two nozzles which are arranged in a staggered mode are arranged in the channel, and the molten adhesive layer is sprayed and cooled for 5s to 15s by circulating dry air with the temperature of 30 ℃ to 40 ℃, the included angle of 30 DEG to 60 DEG with the running direction of the adhesive layer and the air speed of 8m/s to 12m/s, so that the molten adhesive layer starts to be subjected to inward uniform phase change gelation from the gel skin; And (3) conveying the molten adhesive layer into a constant temperature maintaining area, and standing for 10-30 min in low-flow-rate circulating air at the temperature of 30-40 ℃ to enable molecular chain segments in the molten adhesive layer to sufficiently relax, so that the gel adhesive film is formed.
  6. 6. The method for preparing a self-adhesive label based on gel state transfer coating according to claim 1, wherein after the gel state adhesive film is pressed with a label surface material, the first release carrier is peeled off, so that the gel state adhesive film on the first release carrier is transferred to the label surface material to form an adhesive surface layer, comprising: Performing preliminary alignment on the gel-state adhesive film and the label surface material in a loose state to obtain an alignment complex; Introducing the alignment complex into a pressing roller set consisting of an active steel roller and a driven roller coated with a silica gel layer, wherein the line pressure of the pressing roller set is 20N/cm-60N/cm, and the pressing speed is 10 m/min-50 m/min; And stripping the first release carrier at a stripping angle of 110-135 degrees with a horizontal plane and a constant stripping force of 0.5N/cm-2N/cm, so that the gel-state adhesive film is completely transferred to the label surface material, and the adhesive surface layer is obtained.
  7. 7. The method for preparing a self-adhesive label based on gel state transfer coating according to claim 6, wherein the preliminary alignment of the gel state adhesive film and the label surface material in a loose state is performed, and before the alignment complex is obtained, the method further comprises: And (3) sequentially carrying out corona treatment on the label material through a corona treatment area and cleaning treatment through an ion wind dust removal area to obtain the label surface material with the microstructure surface, wherein the strength of the corona treatment is 8 kW & min/m < 2 > -15 kW & min/m < 2 >.
  8. 8. The method for preparing a self-adhesive label based on gel state transfer coating as claimed in claim 1, wherein the step of compounding the adhesive surface layer with a second release carrier to obtain the self-adhesive label comprises the following steps: And rolling the adhesive surface of the adhesive surface layer and the release surface of the second release carrier to obtain the self-adhesive label, wherein the roller pressure is 0.1-0.3 MPa.
  9. 9. A self-adhesive label preparation system based on gel state transfer coating, which is characterized by comprising: The coating mechanism is used for coating the hot-melt pressure-sensitive adhesive heated to the melt flow temperature on the first release carrier so as to form a melt adhesive layer on the surface of the first release carrier; The cooling mechanism is used for cooling the molten adhesive layer to the gelation temperature in a gradient way, so that the molten adhesive layer is gelled from outside to inside to form a gel-state adhesive film; the transfer mechanism is used for peeling the first release carrier after the gel-state adhesive film and the label surface material are pressed, so that the gel-state adhesive film on the first release carrier is transferred to the label surface material to form a rubberized surface layer on the surface of the label surface material; And the compounding mechanism is used for compounding the adhesive surface layer with the second release carrier to obtain the self-adhesive label.
  10. 10. A self-adhesive label, characterized in that it is produced based on the self-adhesive label producing method according to any one of claims 1 to 8.

Description

Preparation method of self-adhesive label based on gel state transfer coating Technical Field The application relates to the technical field of self-adhesive labels, in particular to a preparation method of a self-adhesive label based on gel state transfer coating. Background The self-adhesive label has convenient use and wide adaptability, and is widely applied to the fields of logistics, retail, food packaging, industrial identification, daily necessities and the like. The core structure of the label comprises a surface material, a pressure-sensitive adhesive layer and release paper (or release film), and the coating and compounding process of the pressure-sensitive adhesive is a key link for determining the performance, the production efficiency and the environmental influence of the label. Currently, the mainstream technology in the industry is mainly developed around hot-melt pressure-sensitive adhesives and aqueous/solvent-type pressure-sensitive adhesives. The hot-melt pressure-sensitive adhesive is coated and thermally compounded after being heated and melted, but colloid is easy to flow in a thermal state, so that glue overflow and poor appearance are caused, the hot-melt pressure-sensitive adhesive needs to be cooled and solidified for a long time, the production efficiency is low, the high-temperature process is not suitable for a thermosensitive material, the local coating of the water-based adhesive is usually only to coat the water-based adhesive on the edge of a label, the whole adhesive force of the label is weak, the label is easy to fall off, and in order to realize the local coating, the equipment is required to be complex, and the precision requirement is high. Disclosure of Invention The application provides a preparation method of a self-adhesive label based on gel state transfer coating, which aims to solve the technical problems of glue overflow phenomenon and low production efficiency in the current self-adhesive label preparation process. In a first aspect, the application provides a method for preparing a self-adhesive label based on gel state transfer coating, which comprises the following steps: Coating a hot-melt pressure-sensitive adhesive heated to a melt flow temperature on a first release carrier to form a melt adhesive layer on the surface of the first release carrier; Cooling the molten adhesive layer in a gradient manner to a gelation temperature to gel the molten adhesive layer from outside to inside so as to form a gel-state adhesive film; After the gel state adhesive film and the label surface material are pressed, the first release carrier is peeled off, so that the gel state adhesive film on the first release carrier is transferred to the label surface material to form a surface layer with adhesive on the surface of the label surface material; and compounding the adhesive surface layer with a second release carrier to obtain the self-adhesive label. In some embodiments, the hot-melt pressure-sensitive adhesive heated to a melt flow temperature is applied to a first release carrier to form a melt adhesive layer on the microstructured surface of the first release carrier, comprising: And preheating the surface temperature of the first release carrier to 50-70 ℃ through a preheating roller, and coating a hot-melt pressure-sensitive adhesive with the temperature of 155-170 ℃ on the microstructure surface of the first release carrier to form the molten adhesive layer, wherein the coating amount is 15 g/m < 2 > -25 g/m < 2 >, and the coating pressure is 0.15-0.3 MPa. In some of these embodiments, the gradient cooling of the molten gel layer to a gelation temperature causes the molten gel layer to gel from the outside to the inside to form a gel state film, comprising: contacting the molten adhesive layer on the first release carrier with a cooling roller set for 1 s-3 s to form a gel skin by rapid cooling on the surface layer of the molten adhesive layer, wherein the surface temperature of the cooling roller set is 10-20 ℃ lower than the softening point of the hot-melt pressure-sensitive adhesive; And (3) treating the molten adhesive layer for 5 s-15 s by using circulating air at 25-40 ℃ to gel the molten adhesive layer from the gel surface layer to the inside, and then sending the molten adhesive layer into an environment at 30-45 ℃ to stand for 10-30 min to obtain the gel adhesive film. In some embodiments, the surface of the main cooling roller of the cooling roller set has a non-smooth microstructure, the microstructure is hemispherical or prismatic micro-protrusions arranged in an array, the height of the micro-protrusions is 10-50 μm, and the center-to-center distance is 100-300 μm. In some embodiments, the treating the molten glue layer with 250 ℃ to 40 ℃ circulating air for 5s to 15s to gel the molten glue layer from the gel skin to the inside, and then sending the gel skin to stand for 10min to 30min under the environment of 30 ℃ to 45 ℃ to obtain a gel-state glu