Gluing method for producing reflective film

Abstract

The invention discloses a back gluing method for producing a reflective film, which comprises the following steps: S1, taking a temporary release backing, uniformly coating glue on the temporary release backing, and drying to accelerate the volatilization of a solvent in the glue to obtain a glue layer; s2, compounding the adhesive layer obtained in the step S1 with a back-adhesive-free reflective film to obtain a reflective film with a temporary release backing; s3, taking a permanent release backing, uniformly coating the permanent release backing with glue, and drying to accelerate volatilization of a solvent in the glue to obtain a glue layer; and S4, stripping the temporary release backing of the reflective film obtained in the step S2, and compounding the adhesive layer obtained in the step S3 with the reflective film with the adhesive layer and without the backing in the step S2 to obtain the reflective finished film with the permanent release backing. According to the method, two times of coating are completed in a low-temperature environment, and the high-adhesion flitch construction performance of the reflective film is effectively kept.

Description

Technical Field

[0001] The invention relates to the technical field of reflective films, and in particular to a back adhesive method for producing reflective films. Background Art

[0002] In the process of producing reflective film, the last step is coating and compounding pressure-sensitive adhesive, and compounding the reflective film and release substrate under the action of adhesive to complete the production of reflective finished film. CN111746012B discloses a method for preparing reflective adhesive film. By replacing the initial release substrate, the problem of direct coating of adhesive causing the reflective film to have a decreased stickiness, hot coating of adhesive causing serious deformation of key reflective components, and a high rate of brightness reduction of the reflective film is solved, so as to maintain the high viscosity adhesive adhesion performance of the reflective film and stabilize the lightness performance of the reflective film. However, this method still has some shortcomings: first, the release backing must have a certain high temperature resistance; secondly, after the release substrate coated with glue passes through a relatively high temperature drying channel, the release backing is easily deformed, resulting in the silicone oil layer on the release backing being easily delaminated. When the silicone oil combines with the adhesive, that is, the silicone oil sticks to the adhesive film layer, the silicone oil is transferred from the release backing to the pressure-sensitive adhesive, resulting in reduced adhesion performance of the reflective film after being attached to the board; in addition, the backing that has been dried at a relatively high temperature is compounded with the non-adhesive reflective film at room temperature, because the backing is in a tension-tightened state at a relatively high temperature. When the ambient temperature drops and cools down, the backing shrinks under the action of the recovery stress, and the adhesive layer on the backing also shrinks accordingly, resulting in the shrinkage and wrinkling of the reflective film body with the adhesive backing under the action of the adhesive force, which greatly affects the appearance of the reflective film before construction and the adhesion quality of the board after construction. Summary of the invention

[0003] The present invention provides a method for producing a back adhesive of a reflective film, thereby solving the problems of transfer of back silicone oil, insufficient adhesion performance of the finished reflective film, wrinkling of the appearance and other undesirable phenomena caused by drying the self-adhesive coated on the back at a relatively high temperature, and realizing the production of the reflective film by coating and compounding the back adhesive in a relatively low temperature environment, thereby effectively maintaining the high adhesion performance of the reflective film in the construction of a board.

[0004] A method for producing a back adhesive of a reflective film comprises the following steps: S1: Take a temporary release backing, evenly apply glue on the temporary release backing, and accelerate the volatilization of the solvent in the glue by drying to obtain a glue layer; S2: Compounding the adhesive layer obtained in S1 with the non-adhesive reflective film to obtain a reflective film with a temporary release backing; S3: taking a permanent release backing, evenly coating the glue on the permanent release backing, and accelerating the volatilization of the solvent in the glue by drying to obtain an adhesive layer; S4: Peel off the temporary release backing of the reflective film obtained in S2, and compound the adhesive layer obtained in S3 with the reflective film with an adhesive layer but no backing in S2 to obtain a finished reflective film with a permanent release backing.

[0005] Furthermore, the temporary release backing has a silicone oil layer, the release force of the release backing is 10 g / 25mm to 15 g / 25mm, the thickness of the adhesive layer coated on the temporary backing is 0.15mm to 0.2mm, and the drying temperature is 100°C to 110°C.

[0006] Furthermore, the permanent release backing has a silicone oil layer, the release force of the release backing is 10 g / 25mm to 15 g / 25mm, the thickness of the adhesive layer coated on the permanent backing is 0.1mm to 0.15mm, and the drying temperature is 100°C to 110°C.

[0007] Furthermore, the temporary release backing and the permanent release backing are made of the same material, preferably one of PP release film, PE release film, PET release film, CPP release film, single-plastic single-silicone release white paper, and double-plastic single-silicone release yellow paper.

[0008] One or more technical solutions provided by the present invention have at least the following technical effects or advantages: This method can further speed up the operation of the equipment because the coating is thin and the required drying temperature is low; The required drying temperature is lower, the temperature resistance requirement of the backing is reduced, and the application range of the backing is expanded; The required drying temperature is low, the backing is not easy to deform under tension, the silicone oil layer and the backing are not easy to delaminate, and can be relatively complete and consistent; The temporary release backing and the permanent release backing are made of the same material. After being peeled off, the temporary release backing can be recycled as a temporary release backing or reused as a permanent release backing for many times; Compared with the adhesive layer that is too sticky on the outside and insufficient on the inside due to a higher temperature drying environment and a thicker single coating drying amount, the adhesive method of the present invention uses a lower temperature drying environment and a thinner double coating drying method, and the adhesion between the inside and outside of the adhesive layer is closer, which can more effectively ensure the uniformity and consistency of the glue viscosity, and the adhesion stability of the reflective film board after construction is stronger. DETAILED DESCRIPTION

[0009] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification and specific implementation methods.

[0010] Example S1: Take a temporary release backing, evenly apply glue on the temporary release backing, and accelerate the volatilization of the solvent in the glue by drying to obtain a glue layer. The specific production method is to take a 0.085mm matte transparent PE single silicone release film, place the release film at the bottom of the glue groove of the 0.18mm composite gap knife edge, with the silicone oil side facing the glue outlet, and fill the glue groove with 5311 thermosetting pressure-sensitive adhesive. Set the running speed to 7m / min so that the glue is evenly applied on the silicone oil surface of the release film, and then pass through a drying tunnel with a multi-zone drying area with a maximum temperature of 105°C and a step-by-step heating, and finally cool it to obtain a 0.18mm glue layer.

[0011] S2: Compounding the adhesive layer obtained in S1 with the non-adhesive reflective film to obtain a reflective film with a temporary release backing. The specific production method is to compound the 0.18 mm adhesive layer with the non-adhesive reflective film to obtain a reflective film with a PE single silicon release film.

[0012] S3: Take a permanent release backing, evenly apply glue on the permanent release backing, and accelerate the volatilization of the solvent in the glue by drying to obtain a glue layer. The specific production method is to take a 0.085mm matte transparent PE single silicone release film, place the release film at the bottom of the glue groove of the 0.1mm composite gap knife edge, with the silicone oil side facing the glue outlet, and fill the glue groove with 5311 thermosetting pressure-sensitive adhesive. Set the running speed to 8m / min so that the glue is evenly applied on the silicone oil surface of the release film, and then pass through a drying tunnel with a multi-zone drying area with a maximum temperature of 105°C and a step-by-step heating, and finally cool it to obtain a 0.1mm glue layer.

[0013] S4: peel off the temporary release backing of the reflective film obtained in S2, and compound the adhesive layer obtained in S3 with the reflective film with an adhesive layer but no backing in S2 to obtain a reflective finished film with a permanent release backing. The specific production method is to peel off the PE single silicon release film of the reflective film S2, and compound the adhesive layer with a thickness of 0.1mm of the PE single silicon release film obtained in S3 with the reflective film with a thickness of 0.18mm and no PE single silicon release film in S2 to obtain a reflective finished film with a PE single silicon release film with an adhesive layer thickness of 0.28mm.

[0014] Comparative Example S1: Take a temporary release backing, evenly apply glue on the temporary release backing, and accelerate the volatilization of the solvent in the glue by drying to obtain a glue layer. The specific production method is to take a 0.085mm matte transparent PE single silicone release film, place the release film at the bottom of the glue groove of the 0.28mm composite gap knife edge, with the silicone oil side facing the glue outlet, and fill the glue groove with 5311 thermosetting pressure-sensitive adhesive. Set the running speed to 5m / min so that the glue is evenly applied on the silicone oil surface of the release film, and then pass through a drying tunnel with a multi-zone drying area with a maximum temperature of 115°C and a step-by-step heating, and finally cool it to obtain a 0.28mm glue layer.

[0015] S2: Compounding the adhesive layer obtained in S1 with the non-adhesive reflective film to obtain a reflective film with a temporary release backing. The specific production method is to compound the 0.28 mm adhesive layer with the non-adhesive reflective film to obtain a reflective film with a PE single silicon release film.

[0016] S3: Take a permanent release backing. The specific production method is to take a 0.085mm matte transparent PE single silicon release film.

[0017] S4: peel off the temporary release backing of the reflective film obtained from S2, and compound the permanent release backing of S3 with the reflective film with adhesive layer and no backing in S2 to obtain a reflective finished film with permanent release backing. The specific production method is to peel off the PE single silicon release film that has been through a drying tunnel of the reflective film of S2, and compound the PE single silicon release film that has not been through a drying tunnel of S3 with the reflective film with 0.28mm thick adhesive layer and no PE single silicon release film in S2 to obtain a reflective finished film with PE single silicon release film that has not been through a drying tunnel and the adhesive layer thickness is 0.28mm.

[0018] The experimental detection methods adopted in the embodiments and comparative examples are the same, which are as follows: Peel strength test: Take the reflective finished film produced in the embodiment and the comparative example, cut off the 5cm×25cm sample reflective film respectively, tear off the 15cm long anti-adhesive paper, paste it on a 5cm×25cm, 2mm thick smooth aluminum alloy plate, and leave the remaining 10cm. After compaction, it is a test sample. The test sample is placed in an environment of 23℃±5℃ and relative humidity not more than 75% for 24h before the test. According to the requirements of GA406-2002, after 24h adhesion test, the test sample bottom plate is fixed on the computer tensile testing machine (Xiamen Dongshi Testing Equipment Co., Ltd.) model DS-218, and the reflective film without the anti-adhesive paper is clamped with the chuck of the tensile testing machine to make it 90° with the bottom plate. The load should be evenly distributed on the width of the sample, and then the 90° peel strength F of the back adhesive of the reflective film sample is measured at a certain rate (304.8mm / min).

[0019] The test results of the reflective film of the comparative example are shown in Table 1, and the test results of the reflective film of the embodiment are shown in Table 2:

[0020] Table 1

[0021] Table 2 Adhesion performance (peel length) test: Take the finished reflective film produced in the embodiment and comparative example, cut a 25mm×200mm reflective film sample, remove 100mm of anti-adhesive paper from one end to expose the adhesive, and paste it on a 50mm×200mm, 1.0mm-2.0mm thick aluminum alloy plate that has been properly polished and cleaned, and leave the remaining 100mm to make an adhesion performance sample. Place the sample reflective film downward on the adhesion performance test stand. Hang a 800g±4g weight on the remaining end of the reflective film, and hang it at an angle of 90° to the sample plate surface. After 5 minutes, measure the length L of the peeled reflective film.

[0022] The test results of the reflective film of the comparative example are shown in Table 3, and the test results of the reflective film of the embodiment are shown in Table 4:

[0023] Table 3

[0024] Table 4 According to the above-mentioned Table 1 and Table 2, the peeling strength of the embodiments and comparative examples meets the requirements of the adhesion performance in the reference standard GA406-2002, and the peeling strength of the adhesive of the reflective film should not be less than 25N. The peeling length of the adhesive performance of the embodiments and comparative examples in Table 3 and Table 4 is based on the requirements of the adhesion performance in the road traffic reflective film standard GB∕T 18833-2012. The adhesive of the reflective film should have sufficient adhesion and the bonding between the structural layers should be firm. After the peeling length test, the peeling length after 5 minutes should not be greater than 20mm.

[0025] Comparing Table 1 and Table 2, the average peel strength of the comparative example of single coating of 0.28mm thick back glue in a drying environment with a maximum temperature of 115°C is maintained at 26N~28N, while the average peel strength of the embodiment of coating the back glue twice with thicknesses of 0.18mm and 0.1mm separately in a drying environment with a maximum temperature of 105°C is as high as 37N~41N, which is 11N~13N higher than the peel strength of the comparative example.

[0026] Comparing Table 3 and Table 4, the average peeling length of the control example in which the back glue was coated once with a thickness of 0.28 mm in a drying environment with a maximum temperature of 115°C was 5mm to 12mm, while the average peeling length of the embodiment in which the back glue was coated twice with thicknesses of 0.18 mm and 0.1 mm in a drying environment with a maximum temperature of 105°C was only 2mm to 5mm, which was 3mm to 7mm less than the control example.

[0027] It can be seen that for the same or different release materials, the same amount of glue applied, while reducing energy consumption by 10°C, the gluing is done in two times, the gluing speed is increased from 5m / min to 7m / min~8m / min per time, the production efficiency is reduced by 20%~30%, but the quality of the glue is improved by 42%~46%, and the amount of peeling is reduced by 58%~60%.

[0028] The above records are only embodiments of the present invention. Any modification or change made by a person familiar with the present technology using the present invention shall fall within the patent scope claimed by the present invention and shall not be limited to those disclosed in the embodiments.

Claims

1. A method for producing a back adhesive for a reflective film, characterized in that: The steps include: S1: Take a temporary release backing, evenly apply glue on the temporary release backing, and accelerate the volatilization of the solvent in the glue by drying to obtain a glue layer; S2: Compounding the adhesive layer obtained in S1 with the non-adhesive reflective film to obtain a reflective film with a temporary release backing; S3: taking a permanent release backing, evenly coating the glue on the permanent release backing, and accelerating the volatilization of the solvent in the glue by drying to obtain an adhesive layer; S4: Peel off the temporary release backing of the reflective film obtained in S2, and compound the adhesive layer obtained in S3 with the reflective film with an adhesive layer but no backing in S2 to obtain a finished reflective film with a permanent release backing.

2. A method for producing a back adhesive for a reflective film according to claim 1, characterized in that: The temporary release backing has a silicone oil layer, the release force of the release backing is 10 g / 25mm-15 g / 25mm, the thickness of the adhesive layer coated on the temporary backing is 0.15mm-0.2mm, and the drying temperature is 100°C-110°C.

3. A method for producing a back adhesive for a reflective film according to claim 1, characterized in that: The permanent release backing has a silicone oil layer, the release backing has a release force of 10 g / 25mm to 15 g / 25mm, the thickness of the adhesive layer coated on the permanent backing is 0.1mm to 0.15mm, and the drying temperature is 100°C to 110°C.

4. A method for producing a back adhesive for a reflective film according to claim 1, characterized in that: The temporary release backing and the permanent release backing are made of the same material, preferably one of PP release film, PE release film, PET release film, CPP release film, single plastic single silicon release white paper, and double plastic single silicon release yellow paper.

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