CN114149765B

CN114149765B - Adhesive film, preparation method and application thereof

Info

Publication number: CN114149765B
Application number: CN202210003959.5A
Authority: CN
Inventors: 滕超; 孙书政; 李士锋; 王国伟
Original assignee: Anhui Yicheng Material Science & Technology Co ltd
Current assignee: Lu'anyi New Material Technology Co ltd
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2023-06-27
Anticipated expiration: 2042-01-05
Also published as: CN114149765A

Abstract

The invention provides an adhesive film which comprises a frosted grid release layer, an adhesive layer and a film layer. The invention also provides a method for preparing the adhesive film and application of the adhesive film in advertising, decoration and the like. The adhesive film of the invention basically reaches zero initial adhesion and has good reworkability; meanwhile, the adhesive has high stripping force and good attaching effect; and the preparation process is simple and easy to operate.

Description

Adhesive film, preparation method and application thereof

Technical Field

The invention relates to the field of adhesive materials, in particular to an adhesive film, a preparation method thereof and application thereof in advertising, decoration and the like.

Background

Advertisement propaganda and fitment decorating film has permeated into aspects of human life and work, is widely used in various advertisement and display fields, and large application places such as large malls, high-speed rail stations, subways, office halls, restaurants and the like, and small application places such as refrigerators, automobiles, buses, containers and the like have larger and larger application amounts. At present, patterns and characters are printed on the surface of a base material such as PVC (polyvinyl chloride) in a color digital printing mode or a traditional screen printing mode, the back surface of the base material is coated with a pressure-sensitive adhesive, and the base material is adhered to a specific position in a film-sticking adhesive tape mode.

Because the pasting environment is complicated, the exterior wall, show window, car appearance etc. are mostly non-planar structure, have more irregular corners, need to tear repeatedly when the pad pasting and paste many times until the pad pasting is aimed at the position completely, if the initial adhesion of pressure sensitive adhesive is too big be unfavorable for repetition construction, leave the line defect of gluing easily when pasting again, the substrate tensile deformation etc. is bad, and efficiency of construction and yield are obviously lower. Therefore, the ideal film adhesive tape has extremely low initial adhesion and even no initial adhesion, can be torn off at will, and shows good adhesion immediately after being aligned to the position for construction.

US5008139a discloses a zero-tack pressure-sensitive adhesive layer in which "non-tacky solid particles" are uniformly disposed on the surface of the pressure-sensitive adhesive, with a portion of the particles embedded in the adhesive layer and a portion exposed outside the adhesive. In practical application, the adhesive layer and the adhered object are isolated through the particles, the effect of zero initial adhesion is achieved, the adhesive film can be moved at will until the adhesive position is found, the solid particles are pressed into the adhesive layer through applying pressure, the adhesive layer is contacted with the adhered object, and finally the adhesive force is formed. The technical scheme has the following defects: 1. the equipment and the process for arranging the non-sticky solid particles are high in requirements, the equipment is high in cost, the arrangement quantity, the position and the depth of the particles in unit area and the size and the distribution of the non-sticky solid particles are strictly limited, and the production efficiency and the productivity are necessarily influenced by the high-precision process requirements; 2. the size of the solid particles is larger, generally 10-60 mu m, so that the solid particles can be pressed into the adhesive layer under a larger pressure to establish bonding strength, and the construction efficiency is influenced to a certain extent.

CN110343475a discloses a low-initial-adhesion high-holding-adhesion paint protective film, the formula of the pressure-sensitive adhesive layer of the protective film is: crystalline hydroxyl polyurethane resin, polyol resin, tackifying resin, crosslinking agent, ultraviolet absorber and antioxidant. The protective film prepared by the method has the performances of low initial adhesion, high holding adhesion and the like, and can solve the problem that the construction is not performed by using a film because the initial adhesion of the pressure-sensitive adhesive layer of the protective film is too large. The technical scheme has the following defects: 1. the reduction of the initial adhesion does not represent no initial adhesion at all, and the repeated tearing and pasting is needed when the film is pasted, so that the construction efficiency is affected, and meanwhile, the adhesiveness is reduced when the film is pasted for multiple times; 2. the adhesive force is insufficient due to the fact that the initial adhesive force is reduced through formula adjustment, instant adhesion cannot be completed after the alignment position is constructed, and bad phenomena such as adhesive loss and edge warping of a film can be caused due to the fact that adhesion is unstable; 3. the hardness of the adhesive is increased by reducing the initial adhesion through formula adjustment, so that the adhesive base force is reduced, and the adhesive is easy to deglue when repeatedly torn and stuck.

Therefore, development of an adhesive film with simple and efficient manufacturing process, convenient and effective application, zero initial adhesion and high peeling force has become an urgent problem to be solved in the fields of advertising, decoration film sticking and the like, and has important significance.

Disclosure of Invention

In order to solve the problems, the invention aims to provide an adhesive film with zero initial adhesion and high peeling force; the adhesive film is simple in preparation process, easy to operate in the film pasting process and good in reworkability; can be widely applied to advertising and decoration. The semi-naked solid particles in the adhesive layer and the copying effect of the semi-naked solid particles and the frosted grid release layer enable the solid particles in the adhesive layer to be more stable and orderly kept in the semi-naked state before being adhered. When pasting, there is stable and orderly semi-naked solid particles and can remove the pad pasting at will because of the sticky pad pasting surface, until looking for the pasting position, in pressing the solid particles into gluing through exerting pressure at last, the glue film produces the contact with being glued, discharges the air through dull polish and air duct structure, finally forms the adhesion stress, reaches good laminating effect.

In order to achieve the technical purpose, the invention provides an adhesive film which comprises a frosted grid release layer, an adhesive layer and a film layer which are sequentially connected, wherein the adhesive layer contains solid particles, the joint surface of the adhesive layer and the frosted grid release layer is provided with a frosted and air guide groove structure, and the other surface of the adhesive layer is connected with the film layer.

In some embodiments, the adhesive layer comprises solid particles in an interior and solid particles in a semi-exposed state.

In some embodiments, the frosted and air channel structure of the adhesive layer is formed by the semi-exposed solid particles and their replication with the frosted grid release layer.

In some embodiments, the frosted grid release layer is selected from release film or release paper, and the surface of the substrate is subjected to atomization embossing treatment and then is coated with a release agent to form a release surface. Preferably, the surface roughness of the frosted grid release layer is Ra 2.5-3.5, the protrusion height is 0.5-2 mu m, and the grid is in a diamond, rectangle, square, round, honeycomb or other air guide groove structure.

In some embodiments, the abrasive mesh release layer has a release force of 5 to 30g/25mm.

In some embodiments, the adhesive layer has a thickness of 0.02 to 0.06mm.

In some embodiments, the adhesive layer comprises 0.5 to 5 parts by weight of solid particles having a particle size of 20 to 1000nm.

Preferably, the particle size of the solid particles is 20 to 500nm, and the content of the solid particles is 0.5 to 5 parts by weight.

Preferably, the particle size of the solid particles is 20 to 300nm, and the content of the solid particles is 1.5 to 3 parts by weight.

Preferably, the particle size of the solid particles is 100 to 300nm, and the content of the solid particles is 2 to 3 parts by weight.

Preferably, the solid particles have a particle diameter of 200nm and a content of 2.5 parts by weight.

Preferably, the adhesive layer further comprises 100 parts by weight of an adhesive.

In some embodiments, the solid particles are selected from one or more of the following: alumina, silica, titania, calcium carbonate, barium carbonate, iron oxide, polystyrene, polymethyl methacrylate, polypropylene, polyethylene, melamine, phenolic resin.

Preferably, the solid particles are polymethyl methacrylate resin particles.

In some embodiments, the film layer is selected from the group consisting of PVC film, PP film, PE film, PS film, and has a thickness of 0.03 to 0.15mm.

The invention also provides a method for preparing the adhesive film, which comprises the following steps:

(1) Pre-dispersing solid particles: adding solid particles into a solvent and dispersing at a high speed to obtain a uniformly mixed solid particle dispersion liquid;

(2) And (3) adhesive preparation: mixing a polymer, tackifying resin, a crosslinking agent and a solvent according to a certain proportion, and dispersing at a high speed to obtain an adhesive;

(3) And (3) preparing adhesive coating liquid: adding the solid particle dispersion liquid into the adhesive, and obtaining adhesive coating liquid through high-speed dispersion;

(4) And (3) coating an adhesive layer: coating adhesive coating liquid on the surface of the film layer, and drying to obtain an adhesive layer, wherein part of solid particles are in a semi-naked state;

(5) Preparing a frosted grid release layer: spraying a release agent on the surface of the release substrate after atomization embossing treatment to form a release surface;

(6) And (3) preparation of a glue adhesive film: and (3) attaching one surface of the adhesive layer with the semi-naked solid particles to the release surface of the frosted grid release layer to obtain the adhesive film.

In some embodiments, the solvent is toluene; the particle size of the solid particles is 100-300 nm.

In some embodiments, the adhesive layer has a thickness of 0.02 to 0.06mm and the film layer has a thickness of 0.03 to 0.15mm.

The invention also provides application of the adhesive film in advertising and decoration.

Compared with the prior art, the invention has the beneficial effects that:

(1) The adhesive layer and the adhered objects are isolated by the particles, and expensive particle arrangement equipment and strict process control process are required in the prior art; the adhesive film provided by the invention has a simple preparation process, can be prepared only according to a normal production mode, does not need to additionally add equipment on a coating line, and greatly reduces the cost.

(2) In the prior art, large-particle-size non-sticky solid particles are needed, and the non-sticky solid particles can be implanted into the adhesive only by using large pressure during construction, so that the working efficiency is influenced to a certain extent; the invention uses nano-scale small-particle-size particles, achieves good isolation effect, and can complete implantation with smaller pressure, thereby ensuring smoother operation.

(3) According to the semi-naked solid particles in the adhesive layer and the copying function of the semi-naked solid particles and the frosted grid release layer, the semi-naked solid particles in the adhesive layer can be more stably and orderly kept in a semi-naked state before being adhered, and therefore a better zero initial adhesion effect can be achieved during adhesion.

(4) Most adhesive films reduce initial adhesion by adjusting the formula of the adhesive, pressure-sensitive adhesive water with higher hardness is required to be designed and synthesized, stripping force and adhesive base force are finally sacrificed, and a larger quality hidden trouble exists; the invention can meet the requirement of zero initial adhesion by means of structural design, and the adhesive provided by the invention has higher stripping force and cohesive property and excellent comprehensive performance.

(5) The adhesive layer provided by the invention has a diamond, rectangular, square, round, honeycomb or other air guide groove structures besides the frosting effect, so that the air exhaust property of the adhesive layer and an adherend (such as a wall surface, glass and the like) during bonding can be enhanced, the bonding foaming problem of the adhesive film is solved, and the bonding effect is improved.

Drawings

FIG. 1 is a schematic view of an adhesive film according to an embodiment of the present invention.

FIG. 2 is a schematic view of an adhesive layer according to an embodiment of the invention.

Fig. 3 is a microscopic magnified view of a frosted grid release layer used in an embodiment of the present invention.

Fig. 4 is a microscopic enlarged view of the attachment of the adhesive layer to the release layer of the frosted grid in an embodiment of the present invention.

FIG. 5 is a schematic illustration of an exhaust test performed in an embodiment of the present invention.

1: film layer, 2: adhesive layer, 211: semi-bare solid particles, 212: internal solid particles, 22: adhesive, 3: frosted grid release layer, 31: grid slots, 32: frosted, 51: template, 52: film sample, 53: a thumb.

Detailed Description

The technical scheme in the embodiment of the invention will be described in detail. Reagents, materials, and instruments used in the following examples are available through conventional commercial means unless otherwise indicated. And it is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. The scope of the present application is not limited to the embodiments, but is intended to be within the scope of the following claims. Portions of the drawings are not necessarily drawn to their relative dimensions, and some dimensions and other relevant dimensions are exaggerated in scale and irrelevant or unimportant details are not drawn in order to provide a clearer description and to enable a person skilled in the art to understand the application of the present application.

The invention provides an adhesive film, which comprises a frosted grid release layer 3, an adhesive layer 2 and a film layer 1 which are sequentially connected as shown in figure 1.

The frosted grid release layer 3 is formed by release materials, one surface of the release materials is coated with release agents after atomization embossing treatment to form release surfaces, and the release surfaces can be in regular diamond, rectangle, square, round, honeycomb or other grid structures. Preferably, the release material may be a release film such as PET, PE, PP or PE coated release paper. The surface roughness of the frosted grid release layer is Ra 2.5-3.5, the surface grid is preferably in a diamond structure, and the height of the protrusions of the surface grid release layer is 0.5-2 mu m. The release force of the frosted grid release layer is preferably 5-30 g/25mm.

Fig. 2 is a schematic view of the adhesive layer 2. As shown in fig. 2, the adhesive layer 2 contains solid particles, preferably composed of the adhesive 22 and semi-bare solid particles 211 and internal solid particles 212, and has a thickness of 0.02 to 0.06mm. In the preferred adhesive layer, the adhesive comprises 100 parts by weight, and the solid particles comprise 0.5 to 5 parts by weight, preferably 1.5 to 3 parts by weight, more preferably 2 to 3 parts by weight, and most preferably 2.5 parts by weight. The adhesive can be prepared from a polymer, tackifying resin, a cross-linking agent and a solvent, wherein the content of the polymer is 100 parts by weight, the weight average molecular weight range is 50-150 ten thousand, and the glass transition temperature is-60 ℃ to-30 ℃; the tackifying resin content may be 10 to 50 parts by weight, preferably 20 parts by weight; the content of the crosslinking agent is 0.05 to 2 parts by weight, preferably 1 part by weight. The solid particles may be solid or hollow or porous ellipsoids or spheres or irregular polygonal structures with a particle size of 20 to 1000nm, preferably 20 to 500nm, more preferably 20 to 300nm, more preferably 100 to 300nm, most preferably 200nm. The solid particles may be inorganic solid particles such as alumina, silica, titania, calcium carbonate, barium carbonate, iron oxide, and the like; or organic solid resins such as polystyrene, polymethyl methacrylate, polypropylene, polyethylene, melamine, phenolic resins, and the like. Preferably, the solid particles are polymethyl methacrylate resin particles.

Fig. 4 is a microscopic enlarged view of the joint between the adhesive layer 2 and the frosted grid release layer 3. As shown in fig. 4, the surface of the adhesive layer 2 bonded to the frosted mesh release layer 3 has a frosted and air guide groove structure, and the inside of the surface contains solid particles 212, and the surface has semi-exposed solid particles 211. The other side of the adhesive layer 2 is connected to the film layer and is preferably fixed to the surface of the film layer by means of coating. The frosted and air guide groove structure on the adhesive layer 2 is formed by the duplication of semi-naked solid particles and the frosted grid release layer 3; the frosted grid release layer 3 can copy the frosted part 32 and grid groove 31 structure shown in fig. 3 to the adhesive layer 2 to form a frosted and air guide groove structure of the adhesive. Fig. 3 illustrates an exemplary frosted and grid air guide slot configuration with both grid slots 31 and frosted points 32. The grid shape can be a regular diamond shape, the diagonal length is 445 mu m, the width of the air guide groove is 42 mu m, and the depth is 5-15 mu m.

The film layer is made of PVC film, PP film, PE film, PS film or other suitable materials, preferably cast PVC soft film. The thickness of the film layer is 0.03 to 0.15mm, preferably 0.04 to 0.09mm. The film layer is coated on the supporting film to form, and can be used as a printing surface, and the surface of the film layer can be printed with patterns and characters in a color digital printing mode or a traditional screen printing mode.

When the adhesive film is used, the frosted grid release layer 3 in the adhesive film is removed, the adhesive film is moved until the adhesive position is found, then the semi-naked solid particles are pressed into the adhesive by applying pressure, air is discharged through the air guide groove on the adhesive layer 2, and the adhesive layer is firmly contacted with an adherend.

(1) Pre-dispersing solid particles: adding solid particles with the particle size of 20-1000 nm, preferably 100-300 nm, into a proper solvent, preferably toluene, and dispersing at high speed to obtain a uniformly mixed solid particle dispersion liquid;

(4) And (3) coating an adhesive layer: coating adhesive coating liquid on the surface of a film layer with the thickness of 0.03-0.15 mm, and drying to obtain an adhesive layer with the thickness of 0.02-0.06 mm, wherein part of solid particles are in a semi-naked state;

(5) Preparing a frosted grid release layer: spraying a release agent on the surface of a release substrate, such as the surface of a PET film, after atomization embossing treatment to form a release surface;

Preferably, the coating may be performed using comma knife coating equipment and the drying may be performed under suitable conditions in an oven. The release surface may be in a regular diamond-shaped structure.

The adhesive film can be widely applied to advertising, decoration, etc.

The method for preparing the frosted grid release layer 3 can comprise the following steps:

(1) A film or a paper substrate such as PET, PE, PP is conveyed to a hot pressing area through a conveying roller after PE film coating, the hot pressing area is provided with an upper heating roller and a lower heating roller, and the surface of the upper heating roller is provided with an anti-engraving frosted grid structure;

(2) Heating at 120-180 ℃ to enable the upper heating roller and the lower heating roller to interact to compress the film substrate or the coated paper, and carrying out atomization embossing treatment, so that the structure on the anti-engraving frosted grid roller is transferred to the surface of the film or the paper, and the surface is in a frosted grid structure;

(3) And coating a release agent, preferably an organosilicon release agent, on the surface of the frosted grid structure to obtain a PET, PE or PP frosted grid release film or PE laminated frosted grid release paper serving as a frosted grid release layer 3.

Preparation example of adhesive film

The adhesive film is prepared by the following steps:

(1) Polymethyl methacrylate resin particles with the particle size of 200nm are added into toluene and dispersed at a high speed of 2500rpm for 5min, thus obtaining a polymethyl methacrylate resin dispersion liquid which is uniformly mixed.

(2) 100 parts by weight of a modified acrylic acid ester pressure-sensitive polymer PS-8231 (Kunshan stone chemical industry), 20 parts by weight of rosin resin D-125 (Sichuan chemical industry), 1 part by weight of isocyanate cross-linking agent (Kochia company) and a proper amount of toluene are mixed and dispersed at a high speed for 5min at 2500rpm to obtain the adhesive.

(3) The polymethyl methacrylate resin dispersion was added to the above adhesive and dispersed at a high speed of 2500rpm for 5 minutes to obtain an adhesive coating liquid such that the adhesive content was 100 parts by weight and the polymethyl methacrylate resin particle content was 0.5 parts by weight.

(4) And (3) coating the adhesive coating liquid on the surface of the casting-grade PVC soft film layer by using comma doctor blade coating equipment, and drying (110 ℃/2 min) by using an oven to obtain the adhesive layer. Fig. 2 shows a schematic view of an adhesive layer formed by oven drying an adhesive coating solution, wherein polymethyl methacrylate resin particles are partially in a semi-exposed state and partially deeply embedded in the adhesive. The thickness of the adhesive layer is 0.035mm, the film layer is coated on the supporting film for forming, the thickness of the film layer is 0.05mm, the adhesive layer can be used as a printing surface, and the surface can be printed with patterns and characters by means of color digital printing or traditional screen printing.

(5) And (3) carrying out atomization embossing treatment on the surface of the PET film, and then coating an organosilicon release agent, so that the surface of the obtained release layer has a frosted and regular diamond structure. Fig. 3 shows a microscopic magnification of the frosted grid release layer. The grid shape can be a regular diamond shape, the diagonal length is 445 mu m, the width of the air guide groove is 42 mu m, and the depth is 5-15 mu m.

(6) And (3) attaching the adhesive layer of the adhesive layer to the release surface of the frosted grid release layer to obtain the adhesive film of the embodiment 1. After the release layer is attached to the adhesive layer, an air guide groove can be formed on the surface of the adhesive layer, so that the exhaust performance of the adhesive layer and an adherend (such as a wall surface, glass and the like) during attachment can be enhanced, the problem of attachment foaming is solved, and the attachment effect is improved. Fig. 4 shows a microscopic enlargement of the attachment of the adhesive layer to the release layer of the frosted grid.

When the film needs to be adhered, the supporting film on the surface of the film layer is torn off, and the application of adhesion can be performed.

By a method similar to that of example 1, only the content (adjustment range: 0.5 to 5 parts by weight) and/or particle diameter (20 to 1000 nm) of polymethyl methacrylate resin particles were adjusted, and adhesive films of examples 2 to 13 were obtained. The adhesive film of example 14 was prepared by a similar method to example 1, omitting the above-mentioned steps (1) and (3).

By a method similar to examples 1 to 14, the content (adjustment range: 0 to 2.5 parts by weight) of polymethyl methacrylate resin particles, when the content is 0, the above steps (1) and (3) were omitted and/or the particle diameter (no particles; or the particle diameter was 200 nm) and/or the selection of a release layer (when the release layer was a smooth release film, the above step (5) was omitted, when the release layer was a frosted release film, the above step (5) was adjusted to be only an atomization treatment, and when the release layer was a grid release film, the above step (5) was adjusted to be only an embossing treatment) were adjusted, and the adhesive films of comparative examples 1 to 4 were produced, respectively.

Specific parameters during the preparation of examples 1-14 and comparative examples 1-4 are shown in the following table:

performance testing

The following tests were performed on the adhesive film samples of examples 1 to 14 and comparative examples 1 to 4, respectively:

1. peel force test

The peel force can be indicative of the amount of adhesion between the film and the adherend, as measured according to ASTM D3330. The sample was cut to a width of 25mm and a length of 150 mm. The mixture was left at a temperature of 23℃and a humidity of 50% RH for at least 2 hours. The test specimen was attached to a clean standard steel plate and was pressed back and forth with a 2kg pressing roller. The peeling was performed by a peeling force measuring device (Instron tensile tester, shimadzu corporation) under the conditions of 180℃peeling angle and 300mm/min peeling speed, and the 180℃peeling force value was measured. The average value of n=3 was used as the measurement value.

2. Initial adhesion test

The initial adhesion can be used for representing the instant adhesion generated by the short-time contact between the film and the object to be adhered, and is measured according to the ASTM D6195 method. The samples were cut to a width of 25mm and a length of 200 mm. The mixture was left at a temperature of 23℃and a humidity of 50% RH for at least 2 hours. And bending the test sample to form a ring shape, clamping the overlapping part on an upper clamp of the instrument, clamping the cleaned test plate into a lower clamp, and radially perpendicular to the adhesive tape. The annular tape was lowered at a speed of 300mm/min to contact the test plate, and immediately after full contact (contact area 25mm. Times.25 mm), the annular tape was raised at a speed of 300mm/min and separated from the test plate by "Start" and the data of the test were recorded. The average value of n=3 was used as the measurement value.

3. Retention test

The determination was made according to ASTM D3654 method in order to test the retention/cohesion of the samples. The sample was cut to a width of 25mm and a length of 150 mm. The mixture was left at a temperature of 23℃and a humidity of 50% RH for at least 2 hours. The test specimen was attached to a clean standard steel plate and was pressed back and forth with a 2kg pressing roller. Keeping the attaching area to be 25mm multiplied by 25mm, hanging a weight of 1kg, preserving for 3 days in a 70 ℃ oven, and observing and recording whether the adhesive tape has displacement and the displacement distance.

4. Anti-adhesive residue test

The sample was cut into a width of 20mm, a length of 150mm, attached to a standard steel plate, and pressed back and forth once with a 2kg pressing roller. After standing for 1 hour under standard laboratory conditions, the mixture was put into an oven at 85 ℃ and 85% RH for 24 hours, and then taken out. After the sample was allowed to stand under standard laboratory conditions for 1 hour, the tape was peeled off rapidly, and whether the surface of the sheet had residual adhesive was observed and recorded to test the adhesive force.

5. Exhaust gas testing

A51 mm by 127mm template 51 was prepared, and a spherical depression area having a dimension diameter of 16mm and a depth of 1mm was dug into the template 51. A film sample 52 having a specification of 50mm×50mm was cut, and the film 52 was adhered to the template 51, taking care not to press the film into the recessed area. As shown in fig. 5, the film sample 52 was pressed evenly into the depression with the thumb 53, and pressure was applied sufficiently until it was confirmed that the remaining blisters had reached the minimum size requirement or completely disappeared, as follows: the presence or disappearance of the air bubbles inside the recess is ensured during the pressing process, and no obvious transfer of the air bubbles outside the recess is visible. If the bubbles completely disappear, the bubbles are qualified, and if any obvious bubbles remain in the concave part, the bubbles are unqualified.

The results of the performance test of the adhesive film samples of examples 1 to 14 and comparative examples 1 to 4 are shown in the following table:

from the test results of examples 1 to 14 and comparative examples 1 to 4 shown in the above tables, it can be seen that:

in the embodiments 1-14 of the invention, the frosted grid release layer is used, and the release layer has a frosted and grid air guide groove structure, so that good air exhaust performance can be provided. Even example 14, which does not contain solid particles, has lower initial adhesion due to the structure of the frosted grid release layer, and other properties are also good. In addition, the adhesive layers of examples 1-13 all have solid particles, the content ranges from 0.5 to 5 parts by weight, the particle size ranges from 20 to 1000nm, and the solutions of examples 1-13 have the combination of good air exhaust properties, low initial adhesion, high peeling force, good retention and the like. Preferably, the content of the solid particles is in the range of 0.5-5 parts by weight, the particle size is in the range of 20-500 nm, and the initial adhesion is less than 6.5N/in; further preferably, the content of the solid particles is in the range of 0.5 to 3 parts by weight, the particle size is in the range of 20 to 500nm, and the initial adhesion of the invention is less than 6.5N/in; further preferably, the content of the solid particles is in the range of 1.5 to 3 parts by weight, the particle size is in the range of 20 to 300nm, and the initial adhesion of the invention is less than 3.2N/in; more preferably, the content of the solid particles is 2-3 parts by weight, the particle size is 100-300 nm, and the initial adhesion is less than 2.2N/in; most preferably, the adhesive film of example 5 had the best combination of properties, with a peel force of 14.8N/in, an initial tack of 0N/in, good cohesion (displacement distance in retention test of only 0.2 mm), good resistance to residual glue, no risk of degumping, and good air release.

The adhesive layer of comparative example 1 was free of nano-solid particles, and the release film used was the most popular smooth release film on the market. Compared with examples 1-14, the adhesive surface is smooth and flat, no solid particles protrude, so that the adhesive surface and an adherend can be fully contacted, and the initial adhesion value reaches the highest. And the adhesive surface of comparative example 1 had no air guide groove, and thus was poor in air discharge.

The release film used in comparative example 2 was the most popular smooth release film on the market. In comparison with examples 1 to 14, the adhesive surface was smooth and flat, and the solid particles could not protrude from the surface, resulting in sufficient contact between the adhesive surface and the adherend, and a higher initial adhesion value was achieved. And the adhesive surface of comparative example 2 has no air guide groove, and the prepared adhesive film has poor air exhaust property.

The release film used in comparative example 3 had no embossed structure. The adhesive surface of comparative example 3 was free of an air guide groove, and the produced film was inferior in air release property, although the requirements of high peel force, zero initial adhesion and good holding force were satisfied as compared with examples 1 to 14.

The film of comparative example 4 had better air-release properties due to the use of the mesh release film, but compared with examples 1 to 14, the adhesive surface was smooth and flat due to the absence of the frosted structure, so that the solid particles could not protrude from the surface, resulting in sufficient contact between the adhesive surface and the adherend, and the initial adhesion value reached higher.

The adhesive film provided by the invention can realize high stripping force, zero initial adhesion, and good comprehensive performance of retention force, residual adhesive resistance and exhaust property by combining structural design with formula adjustment. The frosting and grid structure of the frosted grid release paper and the solid particles with specific particle size and content are important factors for the adhesive film to exert the best performance. Because the fluidity of the adhesive is good, the adhesive layer also forms an uneven frosted structure through the copy function of the frosted grid release layer, thereby achieving the purpose of reducing the contact area between the adhesive layer and an adherend and greatly reducing the initial adhesion of the adhesive film. And the surface bulges are hidden in the concave space of the frosted grid release layer, so that the semi-exposed state of solid particles is kept, the adhesive layer and the adhered objects are isolated through the particles, and the effect of zero initial adhesion is achieved. When the adhesive film is used, the frosted grid release layer in the adhesive film is removed, the adhesive film is moved until the adhesive position is found, then solid particles are pressed into the adhesive by applying pressure, air is discharged through the air guide groove formed by the grid structure, and the adhesive layer is firmly contacted with an adherend.

It will be obvious to a person skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above; but that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Accordingly, the embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The adhesive film is characterized by comprising a frosted grid release layer, an adhesive layer and a film layer which are sequentially connected, wherein the adhesive layer contains solid particles, the joint surface of the adhesive layer and the frosted grid release layer is provided with a frosted and air guide groove structure, and the other surface of the adhesive layer is connected with the film layer;

the adhesive is prepared from a polymer, tackifying resin, a cross-linking agent and a solvent;

the solid particles are selected from one or more of the following: alumina, silica, titania, calcium carbonate, barium carbonate, iron oxide, polystyrene, polymethyl methacrylate, polypropylene, polyethylene, melamine, phenolic resin;

the adhesive layer comprises solid particles in an internal part and solid particles in a semi-naked state;

the adhesive layer comprises 100 parts by weight of adhesive;

the adhesive layer comprises 2.5-5 parts by weight of the solid particles;

the solvent is toluene; the particle size of the solid particles is 100-300 nm.

2. The adhesive film according to claim 1, wherein the frosted and air guide groove structure of the adhesive layer is formed by the solid particles in the semi-exposed state and the duplication of the solid particles with the frosted grid release layer.

3. The adhesive film according to claim 1, wherein the frosted grid release layer is selected from a release film or a release paper, and the release surface is formed by spraying a release agent on the surface of the substrate after atomization embossing treatment.

4. The adhesive film according to claim 1, wherein the surface roughness of the frosted grid release layer is Ra 2.5-3.5, the height of the protrusions is 0.5-2 μm, and the grid is a diamond, rectangle, square, round, honeycomb or other shaped air guide groove structure.

5. The adhesive film according to claim 1, wherein the release force of the frosted grid release layer is 5-30 g/25mm.

6. The adhesive film according to claim 1, wherein the adhesive layer has a thickness of 0.02 to 0.06mm.

7. The adhesive film according to claim 1, wherein the particle diameter of the solid particles is 200nm and the content of the solid particles is 2.5 parts by weight.

8. The adhesive film according to claim 1, wherein the solid particles are polymethyl methacrylate resin particles.

9. The adhesive film according to claim 1, wherein the film layer is selected from the group consisting of PVC film, PP film, PE film, PS film, and has a thickness of 0.03 to 0.15 and mm.

10. A method of preparing the adhesive film according to claim 1, comprising the steps of:

(1) Pre-dispersing solid particles: adding the solid particles into a solvent and dispersing at a high speed to obtain a uniformly mixed solid particle dispersion liquid;

(3) And (3) preparing adhesive coating liquid: adding the solid particle dispersion liquid into the adhesive, and obtaining the adhesive coating liquid through high-speed dispersion;

(4) And (3) coating an adhesive layer: coating the adhesive coating liquid on the surface of the film layer, and drying to obtain an adhesive layer, wherein part of the solid particles are in a semi-naked state;

(6) And (3) preparation of a glue adhesive film: and attaching one surface of the adhesive layer with semi-naked solid particles to the release surface of the frosted grid release layer to obtain the adhesive film.

11. The method of claim 10 wherein the adhesive layer has a thickness of 0.02 to 0.06mm and the film layer has a thickness of 0.03 to 0.15mm.

12. Use of the adhesive film of claim 1 in advertising and finishing.