Adhesive tape for polishing resin lens and preparation method of adhesive tape

Abstract

The invention relates to an adhesive tape for resin lens polishing and a preparation method thereof, and relates to the technical field of lens preparation. The invention aims to develop an adhesive tape product which comprises an EVA (Ethylene Vinyl Acetate) hot melt adhesive layer, a polyolefin film layer and a UV (Ultraviolet) viscosity-reducing adhesive layer, and the polyolefin film layer is positioned between the EVA hot melt adhesive layer and the UV viscosity-reducing adhesive layer. Wherein the EVA hot melt adhesive layer comprises ethylene-vinyl acetate copolymer particles and tackifying resin, the melt index of the ethylene-vinyl acetate copolymer particles ranges from 100 g / 10 min to 400 g / 10 min, and the softening point of the tackifying resin is smaller than 100 DEG C; the UV viscosity-reducing adhesive layer is prepared from a prepolymer A, trimethylolpropane triacrylate, a photoinitiator, isocyanate and ethyl acetate. The obtained adhesive tape has the characteristics that the adhesive property is good, the stripping force is reduced after UV irradiation, the polishing adhesive tape can easily fall off from the surface of a resin lens, the surface of the resin lens cannot be damaged, and adhesive cannot be left on the resin lens.

Description

Technical Field

[0001] This invention relates to the field of lens manufacturing technology, and in particular to a resin lens polishing tape and its preparation method. Background Technology

[0002] In the resin lens polishing process, adhesive tape primarily serves a dual purpose: temporary fixation and surface protection. Its main components typically include a substrate, a UV-curable pressure-sensitive adhesive, and a release film. The substrate is usually a transparent polyester film with excellent light transmittance (facilitating UV curing), strength, and flatness. The core of the UV-curable pressure-sensitive adhesive is typically acrylic. In traditional tape structures, the acrylic pressure-sensitive adhesive is bonded to the resin lens, and the polyester coating is bonded to a cryogenic alloy, which is then mounted on the polishing equipment. After polishing, the acrylic layer needs to be separated from the resin lens by washing. This washing process can easily damage the surface of the resin lens, and acrylic pressure-sensitive adhesive residue may remain, leading to defective and unusable resin lenses. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an adhesive tape for polishing resin lenses. The tape comprises an EVA hot melt adhesive coating, a polyolefin film, a UV-resistant pressure-sensitive adhesive, and double-sided release paper. Through synergistic layering and formula optimization, we have obtained a product with excellent adhesion and minimal adhesive residue, which is beneficial for polishing resin lenses and improves yield.

[0004] The first objective of this invention is to provide an adhesive tape comprising an EVA hot melt adhesive layer, a polyolefin film layer, and a UV anti-tack adhesive layer, wherein the polyolefin film layer is located between the EVA hot melt adhesive layer and the UV anti-tack adhesive layer.

[0005] The EVA hot melt adhesive layer comprises ethylene-vinyl acetate copolymer particles and tackifying resin. The melt index of the ethylene-vinyl acetate copolymer particles is between 100-400 g / 10 min, and the softening point of the tackifying resin is <100℃.

[0006] The UV-resistant adhesive layer comprises prepolymer A, trimethylolpropane triacrylate, photoinitiator, isocyanate, and ethyl acetate. Prepolymer A is prepared using the following method:

[0007] S1. Mix 2-ethylhexyl acrylate, butyl acrylate, hydroxyethyl acrylate, acrylic acid, EtAC and organic solvent, heat to a preset temperature, add an initiator and maintain at that temperature to obtain an acrylic polymer;

[0008] S2. Add ethyl isocyanate methacrylate and a catalyst to the acrylic polymer of S1 to obtain prepolymer A.

[0009] Furthermore, by weight, the EVA hot melt adhesive layer contains 50-150 parts of ethylene-vinyl acetate copolymer particles and 5-20 parts of tackifying resin.

[0010] Furthermore, the ethylene-vinyl acetate copolymer particles are selected from Mitsui EVA 210 from Japan and / or Honam VA910 from South Korea.

[0011] Furthermore, the tackifying resin is selected from one or more of rosin-based tackifying resins, terpene-based tackifying resins, and petroleum-based tackifying resins.

[0012] Furthermore, the tackifying resin is selected from one or more of Kraton TP96, Kemao JB100W, and Ganges HM-900.

[0013] Furthermore, the UV-resistant adhesive layer has an adhesion strength greater than 800gf / 25mm before UV irradiation and a peel strength less than 10gf / 25mm after UV irradiation.

[0014] Further, by weight, the UV-resistant adhesive layer contains 50-150 parts of prepolymer A, 5-20 parts of trimethylolpropane triacrylate, 0.5-5 parts of photoinitiator, 0.5-5 parts of isocyanate and 10-50 parts of ethyl acetate.

[0015] Furthermore, the prepolymer A is prepared by the following method:

[0016] S1. Mix 50-100 parts of 2-ethylhexyl acrylate, 10-30 parts of butyl acrylate, 1-10 parts of hydroxyethyl acrylate, 1-10 parts of acrylic acid, and 50-100 parts of EtAC and an organic solvent. Heat the mixture to 60-90°C, add an initiator, and maintain the temperature at this level for 1-10 hours to obtain an acrylic polymer.

[0017] S2. Add 1-10 parts of ethyl isocyanate methacrylate to the acrylic polymer of S1, and react with a catalyst to obtain prepolymer A.

[0018] Furthermore, the material of the polyolefin film layer is selected from one of PO film, CPP film and PE film.

[0019] Furthermore, the thickness of the EVA hot melt adhesive layer is 1-10 μm;

[0020] The thickness of the polyolefin film layer is 50-100 μm;

[0021] The thickness of the UV-resistant adhesive layer is 10-40 μm.

[0022] Furthermore, the tape also includes a double-sided release paper layer, which is located on the side of the UV-resistant adhesive layer away from the polyolefin film layer; wherein:

[0023] (1) The release force of the light release surface is between 3-50gf / 25mm, and the release force of the heavy release surface is between 6-100gf / 25mm. The ratio of the release force of the light release surface to the release force of the heavy release surface is 1: (1.5-3).

[0024] (2) The thickness of the release paper layer for double-sided release is 50-150μm.

[0025] A second object of the present invention is to provide a method for preparing the adhesive tape, comprising the following steps:

[0026] (1) Mix the EVA hot melt adhesive layer formulation with a volatile solvent in a certain proportion to obtain the EVA hot melt adhesive layer coating liquid;

[0027] The UV anti-tack adhesive layer formulation is mixed in proportion to obtain the UV anti-tack adhesive layer coating liquid;

[0028] (2) The coating liquid is coated to form an EVA hot melt adhesive layer and a UV anti-tack adhesive layer, respectively, and the EVA hot melt adhesive layer, polyolefin film layer and UV anti-tack adhesive layer are combined to obtain the tape.

[0029] Furthermore, the volatile solvent is selected from one or more of toluene, xylene, n-hexane, and n-butane.

[0030] Furthermore, by weight, the EVA hot melt adhesive coating liquid contains 50-150 parts of ethylene-vinyl acetate copolymer particles, 5-20 parts of tackifying resin and 200-400 parts of volatile solvent.

[0031] A third objective of this invention is to provide the application of the tape in the polishing of resin lenses.

[0032] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0033] This invention provides a resin lens polishing tape, which consists of an EVA hot melt adhesive coating, a polyolefin film, a UV-resistant pressure-sensitive adhesive, and double-sided release paper. The EVA hot melt adhesive coating exhibits good adhesion to low-temperature alloys and moderate adhesion to the polyolefin film, ensuring easy separation after processing. The polyolefin film possesses good extensibility, adapting to the curved surface of resin lenses. The UV-resistant pressure-sensitive adhesive exhibits reduced peel strength after UV irradiation, allowing the polishing tape to easily detach from the resin lens surface, thus avoiding the risks of residual adhesive and scratches on the lens surface caused by conventional tapes during separation. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0035] The solution involved in this invention is as follows:

[0036] This invention relates to the resin lens processing process, and provides a UV anti-adhesion tape for resin lens polishing and its preparation method, specifically:

[0037] The present invention comprises, from top to bottom, an EVA hot melt adhesive layer, a polyolefin film layer, a UV anti-adhesion adhesive layer, and a double-sided release paper layer. The hot melt adhesive coating exhibits good adhesion to the low-temperature alloy, and the adhesion between the hot melt adhesive layer and the polyolefin film layer is moderate. This ensures that the low-temperature alloy and the resin lens are relatively fixed during polishing, and also facilitates the separation of the low-temperature alloy from the polyolefin film. The greatest advantage lies in the application of the UV anti-adhesion adhesive layer. Through UV irradiation, the adhesion between the adhesive layer and the resin lens is reduced, achieving automatic separation after irradiation. This avoids the risks of residual adhesive and water washing damaging the resin surface of the lens, significantly increasing resin polishing efficiency and yield.

[0038] In one embodiment of the present invention, the raw materials of the hot melt adhesive layer include 100 parts of EVA particles, 10 parts of tackifying resin, and 300 parts of volatile solvent. The EVA (Ethylene Vinyl Acetate Copolymer) particles contain >25% VA, and the tackifying resin has a softening point <100℃. It can be one or more of rosin-based, terpene-based, or petroleum-based tackifying resins, and the hot melt adhesive layer thickness is 2-8 μm.

[0039] in:

[0040] EVA particles: The EVA particles contain >25% VA and have a melt index of 100-400 g / 10 min. The high VA content provides excellent adhesion and breaks down the crystals between polyethylene particles, making them easily soluble in organic solvents, suitable for solution coating. A melt index between 100-400 g / 10 min is beneficial for bonding with cryogenic alloys. A low melt index prevents rapid bonding with cryogenic alloys at low temperatures; an excessively high melt index, with a low molecular weight, can easily lead to problems such as excess adhesive during winding, resulting in poor appearance. The EVA particles used in this invention can be selected from Mitsui EVA 210 (Japan) or Honam VA910 (Korea), etc.

[0041] Tackifying resin: The tackifying resin of this invention is preferably a tackifying resin with a softening point <100℃. Resins with a softening point greater than 100℃ cannot form good adhesion with low-temperature alloys under low-temperature conditions. The tackifying resin of this invention can be selected from Kraton TP96 (terpene-based tackifying resin), Kemao JB100W (rosin-based tackifying resin), Henghe HM-900 (petroleum-based tackifying resin), etc.

[0042] Solvent: The solvent of this invention is a volatile solvent, including but not limited to one or more of toluene, xylene, n-hexane, and n-butane.

[0043] In one embodiment of the present invention, the polyolefin film layer can be one of PO film, CPP film, or PE film, with a thickness of 50-100μm, tensile strength >90MPa, and elongation at break >150%.

[0044] In one embodiment of the present invention, the UV-resistant adhesive layer has a thickness of 10-40 μm, an adhesion strength greater than 800 gf / 25 mm before UV irradiation, and a peel strength less than 10 gf / 25 mm after UV irradiation. If the adhesion strength before UV irradiation is less than 800 gf / 25 mm, it cannot form a good bond with the lens resin, resulting in relative slippage during polishing and poor resin lens formation; if the peel strength after UV irradiation is greater than 10 gf / 25 mm, it is not conducive to the separation of the polishing tape from the resin lens.

[0045] The specific preparation method of the UV-resistant adhesive resin is as follows:

[0046] UV-resistant adhesive prepolymer A: By weight, in a 2L reaction vessel equipped with a thermometer, stirrer, reflux condenser, and nitrogen inlet, add 70 parts of 2-ethylhexyl acrylate (2EHA), 20 parts of butyl acrylate (BA), 5 parts of hydroxyethyl acrylate (HEA), 5 parts of acrylic acid (AA), 60 parts of EtAC, and 40 parts of methyl ethyl ketone solvent. Stir until homogeneous, heat to 75°C, add 0.15 parts of AIBN, maintain the reaction at 75°C for 6 hours, then cool down to obtain an acrylic polymer. Then add 3 parts of ethyl methacrylate isocyanate (MOI) and 0.01 parts of dibutyltin dilaurate, heat to 60°C, and react for 4 hours to obtain a solution of prepolymer A.

[0047] In one embodiment of the present invention, the thickness of the release paper layer for double-sided release is 50-150 μm, the release force of the light release surface is 3-50 gf / 25 mm, and the release force of the heavy release surface is 6-100 gf / 25 mm, with the ratio of the light release surface release force to the heavy release surface release force being approximately 1:2. The preparation method is as follows:

[0048] Step 1: Mix EVA particles, tackifying resin and solvent in a certain proportion to obtain hot melt adhesive coating liquid. The hot melt adhesive coating liquid is coated on the release film (1). The release film is dried in an oven and then hot-pressed onto the polyolefin film layer and rolled up.

[0049] Step 2: Coat the double-sided silicone release paper with UV anti-tack adhesive, dry it in an oven, and then bond it to the non-hot melt adhesive layer of the polyolefin film layer and roll it up.

[0050] Step 3: Tear off the release film layer (1) and roll it up from the back to obtain the UV anti-adhesion tape for polishing resin lenses.

[0051] Example 1

[0052] This embodiment relates to a UV anti-adhesion tape for polishing resin lenses, comprising a 5μm thick hot melt adhesive layer, a 90μm thick polyolefin film layer, a 30μm thick UV anti-adhesion layer, and a 120μm thick double-sided release paper layer, sequentially stacked, and obtained according to the above preparation method. The coating solution of the hot melt adhesive layer, by weight, comprises the following components: 100 parts Mitsui EVA 210 (melt index 400g / 10min), 10 parts Kraton TP96 (softening point 96℃), and 300 parts toluene; the coating solution of the UV anti-adhesion layer comprises the above-mentioned 100 parts prepolymer A, 10 parts trimethylolpropane triacrylate, 1 part photoinitiator TPO, 1 part photoinitiator 184, 1.5 parts isocyanate, and 30 parts ethyl acetate; the polyolefin film layer is a PO film.

[0053] Preparation method:

[0054] Process 1: Release film (1) Hot melt adhesive coating liquid is applied to the release layer, dried in an oven, and then hot-pressed onto the polyolefin film layer and rolled up;

[0055] Step 2: Coat the double-sided silicone release paper with UV anti-tack adhesive, dry it in an oven, and then bond it to the non-hot melt adhesive layer of the polyolefin film layer and roll it up.

[0056] Step 3: Tear off the release film layer (1) and roll it up from the back to obtain the UV anti-adhesion tape for polishing resin lenses.

[0057] Example 2

[0058] The coating solution for the UV-resistant adhesive layer comprises 100 parts of prepolymer A, 15 parts of trimethylolpropane triacrylate, 1 part of photoinitiator TPO, 1 part of photoinitiator 184, 1.5 parts of isocyanate, and 30 parts of ethyl acetate. The remainder is the same as in Example 1.

[0059] Example 3: Different types and amounts of EVA particles and different types and amounts of tackifying resin.

[0060] (1) By weight, the coating liquid of the hot melt adhesive layer comprises the following components: 50 parts of Mitsui EVA 210 (melt index 400 g / 10 min), 20 parts of Kemao JB100W (softening point 95 °C), and 300 parts of toluene. The rest is the same as in Example 2.

[0061] (2) By weight, the coating liquid of the hot melt adhesive layer comprises the following components: 150 parts of Korean Honam VA910 (melt index 400 g / 10 min), 5 parts of Ganges HM-900 (softening point 90 °C), and 300 parts of toluene. The rest is the same as in Example 2.

[0062] Example 4: Different amounts of prepolymer A

[0063] (1) The coating liquid for the UV anti-tack layer includes 50 parts of prepolymer A, 10 parts of trimethylolpropane triacrylate, 1 part of photoinitiator TPO, 1 part of photoinitiator 184, 1.5 parts of isocyanate, and 30 parts of ethyl acetate. The rest is the same as in Example 2.

[0064] (2) The coating liquid for the UV anti-tack layer includes 150 parts of prepolymer A, 10 parts of trimethylolpropane triacrylate, 1 part of photoinitiator TPO, 1 part of photoinitiator 184, 1.5 parts of isocyanate, and 30 parts of ethyl acetate. The rest is the same as in Example 2.

[0065] Comparative Example 1

[0066] The UV-resistant adhesive layer was replaced with a non-UV-resistant adhesive layer, and the coating liquid for the non-UV-resistant adhesive layer was Anzo Chemical Y-1510 adhesive. Everything else was the same as in Example 2.

[0067] Comparative Example 2

[0068] The coating liquid of the hot melt adhesive layer comprises the following components by weight: 100 parts Mitsui EVA 210 (melt index 400 g / 10 min), 10 parts Kraton TP300 (softening point 112 °C), and 300 parts toluene. The rest is the same as in Example 2.

[0069] Comparative Example 3

[0070] The coating liquid of the hot melt adhesive layer comprises the following components by weight: 100 parts of Tosoh EVA760 (melt index 30 g / 10 min), 10 parts of Kraton TP96 (softening point 96 °C), and 300 parts of toluene. The rest is the same as in Example 2.

[0071] Test case

[0072] Performance testing and evaluation:

[0073] UV front steel plate peel force test method: Refer to GB / T 2792 1998 to test the peel force of acrylic pressure-sensitive adhesive layer.

[0074] UV-treated steel plate peel strength test method: After irradiation energy of 1000mJ, peel strength test is performed, referring to GB / T 2792 1998 for testing the peel strength of acrylic pressure-sensitive adhesive.

[0075] Hot melt adhesive layer (70℃*2min adhesion to low temperature alloy): The hot melt adhesive layer is heated at 70℃*2min to observe the adhesion effect with the low temperature alloy. At the same time, the adhesion of the low temperature alloy to the hot melt adhesive layer is evaluated during the lens polishing process.

[0076] After UV irradiation, the coating on the resin lens is removed: The protective tape is ground with a weight of 25g on the edge grinding machine. After grinding, observe whether there is any residual adhesive on the UV-treated lens.

[0077] The test results are as follows:

[0078] Table 1. Test results of different embodiments and comparative examples.

[0079]

[0080] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A type of adhesive tape, characterized in that, It includes an EVA hot melt adhesive layer, a polyolefin film layer, and a UV anti-tack adhesive layer, wherein the polyolefin film layer is located between the EVA hot melt adhesive layer and the UV anti-tack adhesive layer; The EVA hot melt adhesive layer comprises ethylene-vinyl acetate copolymer particles and tackifying resin. The melt index of the ethylene-vinyl acetate copolymer particles is between 100-400 g / 10 min, and the softening point of the tackifying resin is <100℃. The UV-resistant adhesive layer comprises prepolymer A, trimethylolpropane triacrylate, a photoinitiator, isocyanate, and ethyl acetate. Prepolymer A is prepared using the following method: S1. Mix 2-ethylhexyl acrylate, butyl acrylate, hydroxyethyl acrylate, acrylic acid, EtAC and organic solvent, heat to a preset temperature, add an initiator and maintain at that temperature to obtain an acrylic polymer; S2. Add ethyl isocyanate methacrylate and a catalyst to the acrylic polymer of S1 to obtain prepolymer A.

2. The tape according to claim 1, characterized in that, It must contain at least one of the following characteristics: (1) By weight, the EVA hot melt adhesive layer contains 50-150 parts of ethylene-vinyl acetate copolymer particles and 5-20 parts of tackifying resin; (2) The ethylene-vinyl acetate copolymer particles are selected from Mitsui EVA 210 from Japan and / or Honam VA910 from South Korea; (3) The tackifying resin is selected from one or more of rosin-based tackifying resins, terpene-based tackifying resins and petroleum-based tackifying resins.

3. The tape according to claim 2, characterized in that, Rosin-based tackifying resins include Kemao JB100W; And / or, terpene tackifying resins include Kronen TP96; And / or, petroleum-based tackifying resins include Ganges HM-900.

4. The tape according to claim 1, characterized in that, It must contain at least one of the following characteristics: (1) The UV-resistant adhesive layer has an adhesion force greater than 800gf / 25mm before UV irradiation and a peel force less than 10gf / 25mm after UV irradiation; (2) By weight, the UV adhesive layer contains 50-150 parts of prepolymer A, 5-20 parts of trimethylolpropane triacrylate, 0.5-5 parts of photoinitiator, 0.5-5 parts of isocyanate and 10-50 parts of ethyl acetate.

5. The tape according to claim 1, characterized in that, The prepolymer A was prepared by the following method: S1. Mix 50-100 parts of 2-ethylhexyl acrylate, 10-30 parts of butyl acrylate, 1-10 parts of hydroxyethyl acrylate, 1-10 parts of acrylic acid, and 50-100 parts of EtAC and an organic solvent. Heat the mixture to 60-90°C, add an initiator, and maintain the temperature at this level for 1-10 hours to obtain an acrylic polymer. S2. Add 1-10 parts of ethyl isocyanate methacrylate to the acrylic polymer of S1, and react with a catalyst to obtain prepolymer A.

6. The tape according to claim 1, characterized in that, It must contain at least one of the following characteristics: (1) The material of the polyolefin film layer is selected from one of PO film, CPP film and PE film; (2) The thickness of the EVA hot melt adhesive layer is 1-10 μm; (3) The thickness of the polyolefin film layer is 50-100 μm; (4) The thickness of the UV anti-adhesion layer is 10-40 μm.

7. The tape according to claim 1, characterized in that, The tape further includes a double-sided release paper layer, which is located on the side of the UV-resistant adhesive layer away from the polyolefin film layer; wherein, at least one of the following characteristics is included: (1) The release force of the light release surface is between 3-50gf / 25mm, and the release force of the heavy release surface is between 6-100gf / 25mm. The ratio of the release force of the light release surface to the release force of the heavy release surface is 1: (1.5-3). (2) The thickness of the release paper layer for double-sided release is 50-150μm.

8. A method for preparing the adhesive tape according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Mix the EVA hot melt adhesive layer formulation with a volatile solvent in a certain proportion to obtain the EVA hot melt adhesive layer coating liquid; The UV anti-tack adhesive layer formulation is mixed in proportion to obtain the UV anti-tack adhesive layer coating liquid; (2) The coating liquid is coated to form an EVA hot melt adhesive layer and a UV anti-tack adhesive layer, and the EVA hot melt adhesive layer, polyolefin film layer and UV anti-tack adhesive layer are combined to obtain the tape.

9. The preparation method according to claim 8, characterized in that, It must contain at least one of the following characteristics: (1) The volatile solvent is selected from one or more of toluene, xylene, n-hexane, and n-butane; (2) By weight, the EVA hot melt adhesive coating liquid contains 50-150 parts of ethylene-vinyl acetate copolymer particles, 5-20 parts of tackifying resin and 200-400 parts of volatile solvent.

10. The application of the tape according to any one of claims 1-7 or the tape prepared by the preparation method according to claim 8 or 9 in the polishing of resin lenses.

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