Heat-resistant UV viscosity-reducing adhesive composition and preparation method of UV viscosity-reducing adhesive film

Abstract

The invention relates to the technical field of adhesives, in particular to a heat-resistant UV (ultraviolet) viscosity-reducing adhesive composition and a preparation method of a UV viscosity-reducing adhesive film, and the heat-resistant UV viscosity-reducing adhesive composition is prepared by uniformly mixing a multifunctional polyurethane acrylate prepolymer, a multifunctional alkene monomer with a triazine ring, a multifunctional thiol monomer, a photoinitiator, a polymerization inhibitor and other auxiliaries, the mass fraction of the substances is as follows: 50 to 75 parts of the multifunctional polyurethane acrylate prepolymer, 10 to 15 parts of the multifunctional alkene monomer with the triazine ring, 10 to 15 parts of the multifunctional thiol monomer, 1 to 4 parts of the photoinitiator, 0.1 to 0.5 part of the polymerization inhibitor and 0 to 0.1 part of the other auxiliary agents; before ultraviolet light irradiation, the adhesive has good adhesion to a base material, after ultraviolet light irradiation, the viscosity of the adhesive disappears instantly, the adhesive can be easily stripped from the base material instantly, and the adhesive can resist the temperature of 120 DEG C and does not debond at the temperature.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to a preparation method of a heat-resistant UV viscosity-reducing adhesive composition and a UV viscosity-reducing adhesive film. Background Art

[0002] UV viscosity-reducing adhesive is a new type of adhesive material, which is widely used in the semiconductor industry and optical instrument industry. It has good adhesion to the substrate before UV irradiation. After UV irradiation, the adhesion drops instantly, and it can be easily peeled off from the bonded material without affecting the performance of the bonded material. However, in some special application scenarios, such as the laser engraving process of the metal back cover of the mobile phone, it needs to be heated at 120°C or higher for several minutes. This process requires that the viscosity-reducing adhesive has good high temperature resistance in addition to good adhesion and UV viscosity-reducing properties, that is, the adhesion cannot be reduced due to high temperature, and the current conventional UV viscosity-reducing adhesive cannot meet this characteristic.

[0003] Therefore, there have appeared a kind of high temperature resistant UV viscosity reducing adhesive disclosed in the invention patent with announcement number CN113088200B and a kind of high temperature resistant UV self-viscosity reducing acrylic resin additive disclosed in the invention patent with announcement number CN114085312B, acrylic resin containing the same and high temperature resistant UV viscosity reducing film, etc., all of which can achieve high temperature resistance effect.

[0004] However, it was found during use that although the above methods improved the high temperature resistance of the viscosity-reducing adhesive by increasing the cross-linking density of the polymer or introducing some rigid ring structures, the acrylic ester material used was easily inhibited by oxygen in the air during free radical photopolymerization, resulting in insufficient polymerization and some residual adhesive, which affected subsequent processing and resulted in poor practicality. Therefore, there is an urgent need for a UV viscosity-reducing adhesive composition with no oxygen inhibition and good heat resistance and a method for preparing a UV viscosity-reducing adhesive film to improve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a heat-resistant UV viscosity-reducing adhesive composition and a method for preparing a UV viscosity-reducing adhesive film, in which the adhesive has good adhesion to the substrate before ultraviolet light irradiation, the viscosity of the adhesive disappears instantly after ultraviolet light irradiation, and the adhesive can be easily peeled off from the substrate instantly, and can withstand a temperature of 120°C and will not debond at this temperature.

[0006] The heat-resistant UV viscosity-reducing adhesive composition of the present invention is prepared by uniformly mixing a multifunctional polyurethane acrylate prepolymer, a multifunctional olefin monomer with a triazine ring, a multifunctional thiol monomer, a photoinitiator, an inhibitor and other additives;

[0007] The mass fraction of the above substances is:

[0008] 50-75 parts of multifunctional polyurethane acrylate prepolymer, 10-15 parts of multifunctional olefin monomer with triazine ring, 10-15 parts of multifunctional thiol monomer, 1-4 parts of photoinitiator, 0.1-0.5 parts of inhibitor and 0-0.1 parts of other auxiliary agents.

[0009] Preferably, the multifunctional polyurethane acrylate prepolymer is obtained by a condensation reaction of a diol and an aromatic diisocyanate under the action of an organic tin catalyst to obtain an -NCO-terminated polyurethane prepolymer, which is then terminated by trimethylolpropane diacrylate or pentaerythritol triacrylate to obtain a multifunctional polyurethane acrylate prepolymer.

[0010] Preferably, the multifunctional vinyl monomer with a triazine ring is triallyl isocyanurate and its derivatives.

[0011] Preferably, the multifunctional thiol monomer is one or more of multifunctional 3-mercaptopropionate esters and 3-mercaptoacetate esters.

[0012] Preferably, the photoinitiator consists of cleavage-type and hydrogen-abstraction-type free radical photoinitiators;

[0013] The mass ratio of the cleavage type photoinitiator to the hydrogenation type photoinitiator is 10 / 90-90 / 10.

[0014] Preferably, the polymerization inhibitor is one or more of a phenolic polymerization inhibitor, a quinone polymerization inhibitor, and an organic metal polymerization inhibitor.

[0015] Preferably, the other additives include one or more of a leveling agent, a surfactant, an antioxidant, and a defoaming agent.

[0016] The invention discloses a method for preparing a heat-resistant UV anti-viscosity adhesive film, which comprises a protective layer, a UV anti-viscosity layer and a substrate;

[0017] The UV anti-viscosity layer is composed of a heat-resistant UV anti-viscosity adhesive composition.

[0018] Preferably, the substrate is a polyester film or a polyolefin film, and the thickness of the UV anti-adhesion layer is 25±5 μm.

[0019] Preferably, the protective layer is a polyethylene film, and its thickness is 10±2 μm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Before UV irradiation, the adhesive has good adhesion to the substrate. After UV irradiation, the adhesive's stickiness disappears instantly and can be easily peeled off from the substrate instantly. It can also withstand temperatures of 120°C and will not debond at this temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the heat-resistant UV-reducing adhesive film of the present invention.

[0023] Markings in the attached drawings: 1, substrate; 2, UV anti-adhesion layer; 3, protective film. DETAILED DESCRIPTION

[0024] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0025] A heat-resistant UV-resistant adhesive composition is prepared by uniformly mixing a multifunctional polyurethane acrylate prepolymer, a multifunctional olefin monomer with a triazine ring, a multifunctional thiol monomer, a photoinitiator, an inhibitor and other additives;

[0026] The mass fraction of the above substances is:

[0027] 50-75 parts of multifunctional polyurethane acrylate prepolymer, 10-15 parts of multifunctional olefin monomer with triazine ring, 10-15 parts of multifunctional thiol monomer, 1-4 parts of photoinitiator, 0.1-0.5 parts of inhibitor and 0-0.1 parts of other additives;

[0028] The multifunctional polyurethane acrylate prepolymer is obtained by polycondensation reaction of diol and aromatic diisocyanate under the action of an organic tin catalyst to obtain an -NCO-terminated polyurethane prepolymer, which is then terminated by trimethylolpropane diacrylate or pentaerythritol triacrylate to obtain a multifunctional polyurethane acrylate prepolymer;

[0029] The multifunctional olefin monomer with a triazine ring is triallyl isocyanurate and its derivatives;

[0030] The multifunctional thiol monomer is one or more of multifunctional 3-mercaptopropionate esters and 3-mercaptoacetate esters;

[0031] The photoinitiator is composed of cleavage-type and hydrogen-abstraction-type free radical photoinitiators;

[0032] The mass ratio of the cleavage type photoinitiator to the hydrogenation type photoinitiator is 10 / 90-90 / 10;

[0033] The polymerization inhibitor is one or more of a phenolic polymerization inhibitor, a quinone polymerization inhibitor, and an organic metal polymerization inhibitor;

[0034] The other additives include one or more of a leveling agent, a surfactant, an antioxidant, and a defoaming agent.

[0035] like Figure 1 As shown, a method for preparing a heat-resistant UV anti-viscosity adhesive film comprises a protective layer, a UV anti-viscosity layer, and a substrate;

[0036] The UV anti-viscosity layer is composed of a heat-resistant UV anti-viscosity adhesive composition;

[0037] The substrate is a polyester film or a polyolefin film, and the thickness of the UV anti-adhesion layer is 25±5 μm;

[0038] The protective layer is a polyethylene film, and its thickness is 10±2 μm;

[0039] Example:

[0040] The preparation method of the heat-resistant UV-reducing adhesive film comprises:

[0041] Step 1: mixing a diol (e.g., ethylene glycol) and a diisocyanate (e.g., toluene diisocyanate) at a molar ratio of 1:1.5, and performing a polycondensation reaction under the action of an organic tin catalyst (e.g., dibutyltin dilaurate), and controlling the reaction conditions (e.g., temperature 80° C., time 2 hours) to ensure -NCO termination;

[0042] Step 2: performing a capping reaction on the prepolymer and trimethylolpropane diacrylate or pentaerythritol triacrylate at a molar ratio of 1:1 to obtain a multifunctional polyurethane acrylate prepolymer A having a weight average molecular weight of 100,000 to 500,000;

[0043] Prepolymer A is mixed with active monomer B (such as triallyl isocyanurate), thiol monomer C (such as 3-mercaptopropionate), photoinitiator D (such as 2-hydroxy-2-methylpropionic acid phenol methoxyethyl ester and benzophenone), and inhibitor E (such as hydroquinone) in a mass ratio of 75:10:10:1:0.01 to obtain a UV light-curable composition;

[0044] Step 3: evenly coat the prepared UV light-curing composition on a polymer film (PO, PET), and then cover it with a protective release film to obtain a high-temperature resistant UV anti-adhesive film.

[0045] The use methods of high temperature resistant UV anti-viscosity film include:

[0046] S1. Peeling off the protective layer of the heat-resistant UV adhesive film;

[0047] S2, attaching the UV anti-adhesion layer to the surface of the wafer or electronic glass to be processed;

[0048] S3. During the processing, the wafer or electronic glass is heated to 120°C and maintained for 5 minutes;

[0049] S4. After the processing is completed, the adhesive film is irradiated with UV light to peel off the UV anti-adhesion layer from the surface of the wafer or electronic glass.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat-resistant UV viscosity-reducing adhesive composition, characterized in that: It is made by uniformly mixing multifunctional polyurethane acrylate prepolymer, multifunctional olefin monomer with triazine ring, multifunctional thiol monomer, photoinitiator, inhibitor and other additives; The mass fraction of the above substances is: 50-75 parts of multifunctional polyurethane acrylate prepolymer, 10-15 parts of multifunctional olefin monomer with triazine ring, 10-15 parts of multifunctional thiol monomer, 1-4 parts of photoinitiator, 0.1-0.5 parts of inhibitor and 0-0.1 parts of other auxiliary agents.

2. The method for preparing a heat-resistant UV viscosity-reducing adhesive composition and a UV viscosity-reducing adhesive film according to claim 1, characterized in that: The multifunctional polyurethane acrylate prepolymer is obtained by polycondensation reaction of diol and aromatic diisocyanate under the action of an organic tin catalyst to obtain an -NCO-terminated polyurethane prepolymer, which is then terminated by trimethylolpropane diacrylate or pentaerythritol triacrylate to obtain a multifunctional polyurethane acrylate prepolymer.

3. A heat-resistant UV-resistant adhesive composition according to claim 1, characterized in that: The multifunctional olefin monomer with a triazine ring is triallyl isocyanurate and its derivatives.

4. A heat-resistant UV viscosity-reducing adhesive composition as claimed in claim 1, characterized in that: The multifunctional thiol monomer is one or more of multifunctional 3-mercaptopropionate esters and 3-mercaptoacetate esters.

5. A heat-resistant UV viscosity-reducing adhesive composition as claimed in claim 1, characterized in that: The photoinitiator is composed of cleavage-type and hydrogen-abstraction-type free radical photoinitiators; The mass ratio of the cleavage type photoinitiator to the hydrogenation type photoinitiator is 10 / 90-90 / 10.

6. A heat-resistant UV-reducing adhesive composition according to claim 1, characterized in that: The polymerization inhibitor is one or more of a phenolic polymerization inhibitor, a quinone polymerization inhibitor, and an organic metal polymerization inhibitor.

7. A heat-resistant UV-resistant adhesive composition according to claim 1, characterized in that: The other additives include one or more of a leveling agent, a surfactant, an antioxidant, and a defoaming agent.

8. A method for preparing a heat-resistant UV-reducing adhesive film, characterized in that: It consists of a protective layer, a UV viscosity-reducing layer, and a base material; The UV anti-adhesion layer is composed of the composition according to any one of claims 1 to 7.

9. The method for preparing a heat-resistant UV-reducing adhesive film according to claim 8, characterized in that: The substrate is a polyester film or a polyolefin film, and the thickness of the UV anti-adhesion layer is 25±5 μm.

10. The method for preparing a heat-resistant UV-resistant adhesive film according to claim 8, characterized in that: The protective layer is a polyethylene film, and its thickness is 10±2 μm.

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