Optical adhesive tape product, touch control display apparatus, and lamination method thereof
A touch display device and tape technology, applied in the directions of adhesives, adhesive additives, non-polymer adhesive additives, etc., can solve the problems of time-consuming, poor reworkability, etc., and achieve the effect of suppressing the occurrence of bubbles
Inactive Publication Date: 2017-02-15
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AI-Extracted Technical Summary
Problems solved by technology
However, if it is found that there are bubbles in the liquid optical adhesive, since the liquid optical adhesive has cured, after separating the touch module and th...
 Functional group monomers can be copolymerized with soft monomers and hard monomers to form acrylic acid copolymers with functional groups, and the copolymers can be chemically cross-linked to improve heat resistance and aging resistance. Functional monomers are, for example...
an optical adhesive tape product, a touch control display apparatus, and a lamination method thereof. The optical adhesive tape product is prepared through the steps of: 1) blending a soft monomer and a hard monomer to obtain a main agent; 2) adding a hardener to the main agent to obtain an adhesive agent, wherein the weight percentage ratio of the hardener is 0.08-0.18% of the main agent; 3) coating a first release film with the adhesive agent, heating the adhesive agetn to cure the adhesive agent; and 4) laminating a second release film on the cured adhesive agent, wherein the cured adhesive agent is between the first release film and the second release film.
Non-macromolecular adhesive additivesFilm/foil adhesives
- Experimental program(1)
- Effect test(1)
 Figure 1A to 1C It shows a manufacturing process diagram of an optical tape product according to an embodiment of the present invention.
 Such as Figure 1A As shown, after mixing the main agent, the first hardening agent, the second hardening agent, and the additives, the adhesive 110 is formed. Then, the adhesive 110 is coated on the first release film 120. The main agent, the first hardening agent, the second hardening agent, and the additives are described in detail below.
 The main agent can be a blend of soft monomers, hard monomers, functional monomers, thermal initiators and photoinitiators.
 The soft monomer can be a sticky monomer. The soft monomer is, for example, a polymer that can produce a lower glass transition temperature (Tg) and has initial adhesion properties. For example, the soft monomer may be ethyl acrylate, butyl acrylate, isooctyl acrylate, or a combination thereof.
 The hard monomer can be a cohesive monomer. The hard monomer is, for example, a homopolymer that can produce a higher glass transition temperature, and the soft monomer can be copolymerized to improve the cohesive strength of the soft monomer, and help to improve the water resistance and adhesion strength. For example, the hard monomer may be vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, or a combination thereof. In one embodiment, the weight percentage of the hard monomer and the hard monomer may account for more than 60% of the main agent or the adhesive.
 The embodiment of the present invention is a double-sided adhesive. In one embodiment, the main agent is composed of acrylic copolymer. When the intense exothermic reaction of polymerization is carried out, it is difficult to adjust the temperature, so some solvents are used to As the heat transfer medium, the heat transfer can be improved, and the polymerization temperature can be easily controlled. In one embodiment, the solvent is preferably 5% to 15% by weight of the main agent or adhesive toluene and 30% to 60% by weight of the main agent or adhesive as a low-boiling EAC solvent. However, the embodiment of the present invention is not limited by this.
 Functional monomers can be copolymerized with soft monomers and hard monomers to form acrylic copolymers with functional groups, and the copolymers can be chemically crosslinked to improve heat resistance and aging resistance. The functional group monomer is, for example, methacrylic acid, acrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxypropyl diaminoethyl methacrylate. In one embodiment, the functional group monomer can account for more than 60% of the weight of the main agent or the adhesive, but it can also be less than 60%.
 The thermal initiator is, for example, azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO). These two kinds of thermal initiators are thermally decomposable. After the temperature is raised to the decomposition temperature, the initiator of one molecule will be decomposed into free radical molecules with one electron each to start the reaction. Free radicals can attack the double bonds on acrylate monomers, and then combine with them to generate free radicals, and then attack a double bond on acrylate monomers. This chain reaction continues to increase the molecular weight of the polymer. , Until the monomer is consumed, the reaction set is terminated.
 The photoinitiator is, for example, an organic peroxide or an azo compound, preferably an aromatic carbonyl compound, such as a phenyl ketone compound, such as 1,2-diphenyl ethylenedione (BenZil), benzophenone (Benzophenone), Benzoin, and ether derivatives thereof. The weight percentage of the photoinitiator may be 0.1% to 3% of the main agent.
 After the main agent is blended, a first hardener can be added to the main agent, wherein the weight percentage of the first hardener is between 0.08% and 0.18% of the main agent. The first hardening agent is, for example, a cross-linking hardening agent. The first hardener can dissolve extremely well in organic solvents and contains high-polar N-HCO- groups that can wet the substrate or form strong hydrogen bonds and dipole attraction. For example, the first hardener is, for example, polyisocyanate. The first hardening agent can choose the chemical structure C1 shown below.
 In addition, a second hardener and/or additives can be optionally added to the main agent.
 The second hardening agent has the characteristics of long life, small performance deviation, low yellowing resistance, and good heat resistance. For example, the second hardening agent is an epoxy compound. The second hardener is, for example, a compound such as a polyamine or a polyacid anhydride. The second hardener may be cross-linked with the first hardener. The advantages of the second hardener are the epoxy compound with long life, small performance deviation, less yellowing, and good heat resistance to increase its cohesion (retention). The addition amount of the second hardening agent is 0 to 1.5 times that of the first hardening agent. In one embodiment, the second hardening agent may be a chemical structure C2 shown below.
 The additive can be an organosilicon compound, such as a silane coupling agent, which has unique bifunctionality and can promote the combination of organic polymer and inorganic mineral surface, so that the composite material still maintains a certain strength under long-term use. In an embodiment, the weight percentage of the additive may be between 0 and 1 times that of the first hardener. Additives can choose the chemical structure C3 shown below.
 Such as Figure 1A As shown, the adhesive 110 can be coated on the first release film 120. The coating thickness t of the adhesive 110 may be approximately between 20 μm and 350 μm.
 Such as Figure 1B As shown, the adhesive 110 is heated at, for example, about 90 degrees Celsius for about 3 minutes to cure the adhesive 110. Due to the composition of the above-mentioned adhesive 110, the cured adhesive 110 is not completely hardened and still has viscosity, so it can be pasted on a substrate such as a touch module and/or a display module. In addition, the glass transition temperature of the cured adhesive 110 is within a proper range, and therefore has proper viscosity. Furthermore, if the glass transition temperature is too low, the adhesiveness will be too viscous, which may cause uneven glue surface problems after gluing; if the glass transition temperature is too high, the adhesiveness will be poor. The glass transition temperature of the cured adhesive 110 in the embodiment of the present invention is between -50°C and -40°C, preferably between -48°C and -43°C, so it has proper viscosity and makes the glue coating The surface is uniform and has acceptable viscosity.
 Such as Figure 1C As shown, the second release film 130 is attached to the cured adhesive 110, so that the first release film 120, the second release film 130 and the cured adhesive 110 form a chemical tape product 100, wherein the cured adhesive 110 The adhesive 110 is located between the first release film 120 and the second release film 130. Since the two opposite sides of the adhesive 110 are respectively protected by the first release film 120 and the second release film 130, the viscosity of the adhesive 110 is not easily affected by the external environment, such as moisture or impurities. In an embodiment, the material of the first release film 120 and the second release film 130 may be polyethylene terephthalate (PET).
 Figure 2A to 2D A manufacturing process diagram of the touch display device 10 according to an embodiment of the invention is shown.
 Such as Figure 2A As shown, an optical tape product 100 is provided. The optical tape product 100 includes a cured adhesive 110, a first release film 120, and a second release film 130.
 Such as Figure 2B As shown, the first release film 120 and the second release film 130 are removed from the cured adhesive 110 to expose the adhesive 110.
 Such as Figure 2C As shown, the display module 11 and the touch module 12 are pasted with an adhesive 110. In one embodiment, the display module 11 and/or the touch module 12 may include a transparent conductive layer (not shown), such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO) ) And/or aluminum oxide zinc (AZO), and the adhesive 110 can directly contact the transparent conductive layer.
 The embodiment of the present invention is a double-sided adhesive, which has the characteristics of strong initial adhesion, maintaining flexibility in a low temperature environment and/or good adhesion at the level. Since the cured adhesive 110 has viscosity, the relative position between the display module 11 and the touch module 12 can be fixed. In addition, since the cured adhesive 110 is in a solid state, it is convenient to observe whether the adhesive 110 has air bubbles. The adhesive 110 at this stage has not been hardened yet, so it has excellent reworkability. In detail, when poor bonding (such as residual bubbles in the adhesive 110) is found, since the adhesive 110 has not been hardened, the display module 11 and the touch module 12 can be easily separated. In addition, since the adhesive 110 has not been hardened, there is little or no residual glue on the display module 11 and the touch module 12 after separation.
 Such as Figure 2D As shown, the cured adhesive 110 is irradiated with light such as ultraviolet light (UV) to harden the adhesive 110. The adhesive 110 irradiated by ultraviolet light has been hardened, so the display module 11 and the touch module 12 can be bonded more firmly. The glass transition temperature of the adhesive 110 after UV irradiation is in the range of about -40°C to -30°C, and the glass transition temperature is preferably about -35°C to -30°C.
 Please refer to the following tables 1-1 to 1-7, which list the experimental results of the first hardener, the second hardener and the additives in different proportions. For example, the values of the first hardener, the second hardener and the additives in the table are the weight percentages of the main agent. For experimental group 8, the first hardener accounted for 0.08% of the main agent, the second hardener accounted for 0.27% of the main agent, and the additive accounted for 0.18% of the main agent. In addition, the main agent, the first hardening agent, the second hardening agent and the additives of the experimental group are illustrated with acrylic pressure sensitive adhesive, chemical structures C1, C2, and C3 as examples.
 According to the results of experimental groups 1 to 8, since the weight percentage of the first hardener is between 0.08% and 0.18% of the main agent, the weight percentage of the second hardener is between 0 and 1.5 times that of the first hardener. The weight percentage of the additive is between 0 and 1 times of the first hardener. Therefore, the reworkability, trustworthiness test, initial retention, and retention after exposure of the adhesive 110 (indicated by "Retention after UV" in the table), The initial adhesion, after-illumination adhesion (indicated by "UV after adhesion" in the table), and polarizer matching test are all qualified (determined as "OK").
 Taking the heavy-duty test as an example, the cured adhesive 110 is pasted between the two glasses, and it is rolled back and forth twice with a 2 kg roller to make the adhesive 110 adhere closely to the glass. After that, the adhesive 110 between the two glasses was separated by a thin line, and then wiped with an EAC solvent to observe the degree of residual glue on the glass surface. Due to the composition of the adhesive 110 in this case, there is almost no residual glue on the glass or the residual glue amount is within an acceptable range (indicated by "OK").
 In terms of reliability test, the adhesive 110 still has acceptable optical properties (transmittance greater than 99% and fogging degree less than 0.5) after being baked at 95 degrees Celsius for 500 hours. No peeling phenomenon (indicated by "◎") and no foaming phenomenon.
 Table 1-1
 Table 1-2
 Table 1-3
 Table 1-4
 Table 1-5
 Table 1-6
 Table 1-7
 In terms of reliability test, the adhesive 110 still has acceptable optical properties (light transmittance greater than 99% and fogging degree less than 0.5) after 500 hours of baking under an environment of 80% humidity and 95 degrees Celsius. There is no peeling phenomenon (indicated by "◎") and no foaming phenomenon (indicated by "◎") between the adhesive 110 and the substrate.
|Glass transition temperature||40.0 ~ 50.0||°C|
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