Polyurethane adhesive for laser semi-cutting, polyurethane protective film as well as preparation method and application of polyurethane adhesive

Abstract

The invention relates to a polyurethane adhesive for laser semi-cutting, a polyurethane protective film as well as a preparation method and application of the polyurethane adhesive. The polyurethane adhesive for laser semi-cutting is prepared from the following components in parts by weight: 100 parts of polyurethane glue, 3 to 8 parts of a curing agent, 0.1 to 2 parts of an antistatic agent, 0.1 to 2 parts of an antioxidant, 0.1 to 0.5 part of a catalyst and 0.1 to 3 parts of a surfactant, wherein the polyurethane glue is prepared from polycarbonate polyol, polyether polyol and polyester polyol according to the mass ratio of (60 to 90): (10 to 30): (1 to 10). The polyurethane adhesive for laser semi-cutting disclosed by the invention has better heat resistance, hydrolysis resistance, oxidation resistance and wear resistance on the premise of ensuring good stripping force, light transmittance and haze, and is suitable for an OLED (Organic Light Emitting Diode) screen manufacturing process.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane protective films, in particular to polyurethane glue for laser half-cutting, a polyurethane protective film and a preparation method and application thereof. Background Art

[0002] Laser cutting is divided into UV band (355nm) light cutting and infrared band (1065nm) cutting; UV light has a short wavelength and is easier to penetrate, and is usually used for laser full cutting; infrared light is often used for laser half cutting, which cuts the material in half through high-temperature gasification; laser half cutting is a processing technology that uses a laser beam to partially cut the material. As a high-energy-density energy source, the laser beam is focused on the surface of the material, and by precisely controlling the energy output and cutting path, it only cuts a part of the material in the thickness direction, rather than completely cutting the material.

[0003] Patent CN 110317550A introduces the basic process of protective film for OLED process, and provides a balanced protective film that takes into account low tearing voltage, no residual glue, low viscosity of thick coating, and no carbonization during laser cutting. It mainly increases the degree of cross-linking by adding additional hard monomers, so that the protected PI layer will not be carbonized when the material is fully cut by laser. However, it cannot meet the requirements of subsequent laser half-cut detection applications. The presence of glue threads during laser half-cutting can easily be misjudged as defective, affecting the final product yield.

[0004] Patent CN 118853004A introduces a protective film for OLED process of organic silicon system; the main advantage is that the combination of inorganic conductive material and organic conductive material provides more stable anti-static performance. However, there is silicon transfer in the organic silicon system, and the water drop angle on the OLED glass surface changes greatly; the PU system has lower residue than the organic silicon system, and the water drop angle on the glass surface changes less. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a polyurethane adhesive for laser half-cutting, a polyurethane protective film, and a preparation method and application thereof. The polyurethane adhesive for laser half-cutting of the present invention has the characteristics of better heat resistance, low viscosity climb over time, low residue, no glue thread and residual glue after laser half-cutting, etc., under the premise of ensuring good peeling force, transmittance and haze tearing voltage, and is suitable for OLED screen process protection. The polyurethane adhesive for laser half-cutting of the present invention can be used for OLED (organic light-emitting diode) screen protection; the OLED screen process requires laser half-cutting (incomplete cutting to prevent cutting the screen), needle puncture to pick up and tear off the protective film, and light up the screen to detect the screen performance.

[0006] The present invention is achieved through the following technical solutions:

[0007] The first object of the present invention is to provide a polyurethane adhesive for laser half-cutting, which comprises the following components in parts by weight:

[0008]

[0009] The antioxidant is selected from 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and / or 2,2'-thiobis[ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0010] In one embodiment of the present invention, the polyurethane glue is prepared from polycarbonate polyol, polyether polyol and polyester polyol in a mass ratio of (60-90):(10-30):(1-10);

[0011] The polyurethane adhesive for laser half-cutting of the present invention uses polycarbonate polyol as the main material and uses polyether polyol and polyester polyol to synthesize the polyurethane resin. Compared with the materials synthesized by traditional polyether polyol, it has better mechanical properties, better scratch resistance, acid and alkali resistance, and better hydrolysis resistance than polyester polyol.

[0012] In one embodiment of the present invention, the polycarbonate polyol is a difunctional and / or trifunctional polycarbonate;

[0013] Preferably, the number average molecular weight of the polycarbonate polyol is 3000-30000, for example, 3000, 6000, 12000, 20000 or 30000, etc.; the hydroxyl value is 10-50 mgKOH / g, for example, 10 mgKOH / g, 15 mgKOH / g, 20 mgKOH / g, 25 mgKOH / g, 30 mgKOH / g, 35 mgKOH / g, 40 mgKOH / g, 45 mgKOH / g, 50 mgKOH / g, etc.; the viscosity at 21-25° C. is 10000-40000 cps, for example, 10000 cps, 15000 cps, 20000 cps, 25000 cps, 30000 cps, 35000 cps, 40000 cps, etc.

[0014] And / or, the polyether polyol is a difunctional and / or trifunctional polyether polyol;

[0015] Preferably, the number average molecular weight of the polyether polyol is 400 to 4000, for example, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500 or 4000, etc.; the hydroxyl value is 34 to 88 mgKOH / g, for example, 34 mgKOH / g, 40 mgKOH / g, 45 mgKOH / g, 50 mgKOH / g, 55 mgKOH / g, 60 mgKOH / g g, 65mgKOH / g, 70mgKOH / g, 75mgKOH / g, 80mgKOH / g, 85mgKOH / g or 88mgKOH / g, etc.; the viscosity at 21-25°C is 50-600cps, 50cps, 100cps, 150cps, 200cps, 250cps, 300cps, 350cps, 400cps, 450cps, 500cps, 550cps or 600cps, etc.

[0016] And / or, the polyester polyol is a difunctional and / or trifunctional polyester polyol.

[0017] Preferably, the polyester polyol has a number average molecular weight of 300 to 4000, such as 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500 or 4000; a hydroxyl value of 34 to 88 mgKOH / g, such as 34 mgKOH / g, 40 mgKOH / g, 45 mgKOH / g, 50 mgKOH / g, 55 mgKOH / g, 60 mgKOH / g, 65 mgKOH / g, 70 mgKOH / g, 75 mgKOH / g, 80 mgKOH / g, 85 mgKOH / g or 88 mgKOH / g; and a viscosity of 2000 to 30000 cps at 21-252°C. , for example, 2000cps, 3000cps, 4000cps, 5000cps, 6000cps, 7000cps, 8000cps, 9000cps, 10000cps, 11000cps, 12000cps, 13000cps, 14000cps, 15000cps, 16000cps, 17000cps, 18000cps, 19000cps, 20000cps, 21000cps, 22000cps, 23000cps, 24000cps, 25000cps, 26000cps, 27000cps, 28000cps, 29000cps or 30000cps.

[0018] In one embodiment of the present invention, the curing agent is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate;

[0019] Preferably, the curing agent is a dimer, trimer, pentamer or heptamer of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0020] Preferably, the curing agent is a dimer, trimer, pentamer or heptamer of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate, for example, toluene diisocyanate dimer, toluene diisocyanate trimer, toluene diisocyanate pentamer, toluene diisocyanate heptamer, diphenylmethane diisocyanate dimer, diphenylmethane diisocyanate trimer, diphenylmethane diisocyanate pentamer, diphenylmethane diisocyanate heptamer, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, hexamethylene diisocyanate pentamer, hexamethylene diisocyanate heptamer, isophorone diisocyanate dimer, isophorone diisocyanate trimer, isophorone diisocyanate pentamer or isophorone diisocyanate heptamer.

[0021] In one embodiment of the present invention, the antistatic agent is selected from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide salt and / or lithium bis(trifluoromethylsulfonyl)imide.

[0022] In one embodiment of the present invention, the catalyst is dibutyltin dilaurate;

[0023] And / or, the surfactant is an organic silicon leveling agent; preferably, the leveling agent is BYK330.

[0024] The second object of the present invention is to provide a method for preparing the polyurethane glue for laser half-cutting, comprising the following steps: mixing polyurethane glue, curing agent, antistatic agent, antioxidant, catalyst and surfactant in a uniform ratio to obtain the polyurethane glue for laser half-cutting.

[0025] The third object of the present invention is to provide a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer; the polyurethane adhesive layer for laser half-cutting comprises the polyurethane adhesive for laser half-cutting.

[0026] In one embodiment of the present invention, the polyurethane protective film for laser half-cutting comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting, a polyurethane coating, a PET substrate and an antistatic coating.

[0027] In one embodiment of the present invention, the substrate layer comprises one or more of a polyurethane coating, a PET substrate and an antistatic coating;

[0028] The light transmittance of the single-sided antistatic PET or the double-sided antistatic PET is ≥90%; the haze of the single-sided antistatic PET or the double-sided antistatic PET is ≤3%; the heat shrinkage of the single-sided antistatic PET or the double-sided antistatic PET is MD<1.5%, TD<0.5%;

[0029] And / or, the thickness of the substrate layer is 50-125 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 125 μm, etc.; the antistatic surface impedance value of the single-sided antistatic PET or the double-sided antistatic PET is independently 10 4 ~10 9 Ω, for example, 10 4 Ω, 10 5 Ω, 10 6 Ω, 10 7 Ω, 10 8 Ω, 10 9 Ω, etc.

[0030] And / or, the release film layer is a PET single silicon release film with a thickness of 12-125μm, for example, 12μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 125μm, etc.; the release force is 10-60g / 25mm, for example, 10g / 25mm, 15g / 25mm, 20g / 25mm, 25g / 25mm, 30g / 25mm, 35g / 25mm, 40g / 25mm, 45g / 25mm, 50g / 25mm, 55g / 25mm, 60g / 25mm, etc.

[0031] And / or, the release film is a single-sided or double-sided antistatic release film, and the impedance value is 10 4 ~10 9 Ω, for example, 10 4 Ω, 10 5 Ω, 10 6 Ω, 10 7 Ω, 10 8 Ω, 10 9 Ω, etc.

[0032] And / or, the thickness of the polyurethane adhesive layer for laser half-cutting is 50-100 μm;

[0033] And / or, the impedance of the polyurethane adhesive layer for laser half cutting is 10 6 ~1011 Ω.

[0034] The fourth object of the present invention is to provide a method for preparing the polyurethane protective film for laser half-cutting, comprising the following steps:

[0035] 1) polyurethane glue, curing agent, antistatic agent, antioxidant, catalyst and surfactant are mixed uniformly according to a proportion, and the solvent is added to make the solid content of the polyurethane glue solution be 30%-50% to prepare the polyurethane glue solution for laser half cutting;

[0036] 2) coating the polyurethane adhesive for laser half-cutting obtained in step 1) on the substrate layer, compounding with the release film after drying, rolling up, and aging to obtain the polyurethane protective film for laser half-cutting.

[0037] In one embodiment of the present invention, the solvent is one or a mixture of at least two of ethyl acetate, toluene, butanone, and xylene;

[0038] And / or, the drying temperature is 80-120°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C;

[0039] And / or, the aging temperature is 40-50°C, for example, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, etc.; the aging time is 60-84h, for example, 60h, 61h, 62h, 63h, 64h, 65h, 66h, 67h, 68h, 69h, 70h, 71h, 72h, 73h, 74h, 75h, 76h, 77h, 78h, 79h, 80h, 81h, 82h, 83h or 84h, etc.

[0040] The fifth object of the present invention is to provide an application of the polyurethane glue for laser half-cutting or the polyurethane protective film for laser half-cutting in the OLED screen manufacturing process.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The polyurethane adhesive for laser half-cutting of the present invention uses polycarbonate polyol as the main material and uses polyether polyol and polyester polyol to synthesize polyurethane resin. Compared with the materials synthesized by traditional polyether polyol, it has better mechanical properties, better scratch resistance and acid and alkali resistance, and better hydrolysis resistance than polyester polyol. Because polyester polyol is easy to hydrolyze, if too much is added, white fog and other undesirable conditions may occur in high temperature and high humidity tests. The present invention also adds antioxidants to enhance the material's resistance to thermal oxidation aging, and the viscosity increase is low after long-term bonding to the OLED screen, and it is not easy to have residual glue. In addition, the benzene ring in the antioxidant is easy to break under infrared energy, so that the material absorbs infrared energy more during laser half-cutting, and the material is easier to break, and the glue threads and glue blocks are reduced after cutting, thereby avoiding pollution to the OLED screen during laser half-cutting. At the same time, the antioxidant contains hydroxyl groups, which can be cross-linked with isocyanate curing agents to form a network structure that increases the cross-linking density of the glue layer, making the glue layer more stable, without small molecule residues, and low residue after long-term bonding to the OLED screen.

[0043] (2) The polyurethane adhesive for laser half-cutting of the present invention has better heat resistance, hydrolysis resistance, oxidation resistance and wear resistance while ensuring good peeling force, light transmittance and haze, and is suitable for OLED screen manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0045] Figure 1 Schematic diagram of the structure of the polyurethane protective film for laser half-cutting in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of laser half-cutting in Example 1 of the present invention;

[0047] Figure 3 It is a schematic diagram of cutting rubber wire in comparative example 6 of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0049] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0050] Example 1

[0051] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue, 5 parts of a trimer curing agent of hexamethylene diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with a solvent such as ethyl acetate or toluene to dilute the mixture to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0052] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (Guodu Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 60:30:10;

[0053] This embodiment provides a polyurethane protective film for laser half-cutting (schematic diagram as shown in FIG. Figure 1 As shown in the figure, from top to bottom are a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0054] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0055] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0056] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0057] Example 2

[0058] The present embodiment provides a polyurethane glue for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 5 parts of a trimer curing agent of hexamethylene diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute the mixture to a solid content of 30%;

[0059] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0060] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0061] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0062] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0063] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0064] Example 3

[0065] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 5 parts of a trimer curing agent of hexamethylene diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0066] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 85:10:5;

[0067] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0068] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0069] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0070] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0071] Example 4

[0072] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of a trimer curing agent of diphenylmethane diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0073] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0074] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0075] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0076] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0077] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0078] Example 5

[0079] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 0.4 parts of antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0080] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0081] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0082] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0083] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0084] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0085] Example 6

[0086] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 0.4 parts of antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0087] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0088] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0089] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0090] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0091] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0092] Example 7

[0093] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 0.4 parts of antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0094] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0095] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 100μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0096] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0097] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0098] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 100 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0099] Example 8

[0100] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 5 parts of a trimer curing agent of isophorone diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0101] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0102] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0103] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0104] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0105] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0106] Example 9

[0107] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 0.4 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0108] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0109] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0110] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0111] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0112] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0113] Example 10

[0114] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 1.2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0115] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0116] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0117] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0118] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0119] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0120] Embodiment 11

[0121] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 0.5 parts of antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0122] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0123] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0124] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0125] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0126] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0127] Example 12

[0128] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 1.2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 0.5 parts of antioxidant, wherein the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]); 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with ethyl acetate, toluene and other solvents to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0129] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0130] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0131] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0132] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0133] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0134] Example 13

[0135] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 1.2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 2 parts of antioxidant, the antioxidant being 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]); 0.5 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with ethyl acetate, toluene and other solvents to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0136] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0137] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0138] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0139] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0140] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0141] Embodiment 14

[0142] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 1.2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 2 parts of antioxidant, the antioxidant being 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]); 0.5 parts of surfactant; 0.5 parts of dibutyltin dilaurate; supplemented with ethyl acetate, toluene and other solvents to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0143] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0144] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0145] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0146] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0147] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0148] Embodiment 15

[0149] The present embodiment provides a polyurethane adhesive for laser half-cutting, the components of which are as follows: 100 parts of polyurethane glue; 6 parts of toluene diisocyanate trimer curing agent; 1.2 parts of antistatic agent (1-ethyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt); 2 parts of antioxidant, the antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]); 2 parts of surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with ethyl acetate, toluene and other solvents to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0150] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 70:20:10;

[0151] The present embodiment provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 75μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0152] The method for preparing the polyurethane protective film for laser half-cutting of this embodiment comprises the following steps:

[0153] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0154] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 75 μm, then laminated with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0155] Comparative Example 1

[0156] The components of the polyurethane adhesive for laser half-cutting in this comparative example are as follows: 100 parts of polyurethane glue; 5 parts of a trimer curing agent of hexamethylene diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0157] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (National Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 50:30:20;

[0158] The present comparative example provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0159] The preparation method of the polyurethane protective film for laser half-cutting of this comparative example comprises the following steps:

[0160] (1) mixing the polyurethane glue, curing agent, antistatic agent, catalyst, surfactant, and diluent, and stirring at room temperature for 30 minutes to obtain a mixed solution, thereby obtaining a polyurethane glue for laser hemisection;

[0161] (2) The polyurethane adhesive for laser half-cutting is coated on the substrate layer, dried at 120° C. to a thickness of 50 μm, then compounded with a release film, rolled up, and aged at 45° C. for 72 hours to obtain the protective film.

[0162] Comparative Example 2

[0163] The components of the polyurethane adhesive for laser half-cutting in this comparative example are as follows: 100 parts of polyurethane glue; 5 parts of a trimer curing agent of hexamethylene diisocyanate; 0.4 parts of an antistatic agent (lithium bistrifluoromethylsulfonyl imide); 0.5 parts of an antioxidant, wherein the antioxidant is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 0.5 parts of a surfactant; 0.2 parts of dibutyltin dilaurate; supplemented with solvents such as ethyl acetate and toluene to dilute to a solid content of 30%; an antistatic polyurethane adhesive prepared by dispersion;

[0164] Among them, the polyurethane glue is polymerized by polycarbonate polyol (Kuraray C-3090 number average molecular weight 3000 hydroxyl value 37), polyether polyol (Guodu Chemical DP2000E number average molecular weight 2000 hydroxyl value 53-58), polyester polyol (Daisy Chemical Co., Ltd. PCL220AL number average molecular weight 2000 hydroxyl value 53-59), and the mass ratio is: 80:0:20;

[0165] The present comparative example provides a polyurethane protective film for laser half-cutting, which comprises, from top to bottom, a release film layer, a polyurethane adhesive layer for laser half-cutting and a substrate layer, wherein the substrate layer is specifically a 50μm PET polyurethane coating film, including a polyurethane coating, a PET substrate and an antistatic coating; the polyurethane adhesive layer for laser half-cutting is obtained by coating the above-mentioned polyurethane adhesive for laser half-cutting; the release film layer is a PET single-silicon double-sided antistatic release film with a thickness of 50μm and a release force of 20g / 25mm.

[0166] The coating appearance of this comparative example is poor, the orange peel is serious, and it cannot be realized.

[0167] Comparative Example 3

[0168] The difference between this comparative example and Example 2 is that the amount of curing agent is 10 parts.

[0169] Comparative Example 4

[0170] The difference between this comparative example and Example 2 is that no antistatic agent is added.

[0171] Comparative Example 5

[0172] The difference between this comparative example and Example 2 is that the amount of antistatic agent added is 3 parts.

[0173] Comparative Example 6

[0174] The difference between this comparative example and Example 2 is that no antioxidant is added.

[0175] Comparative Example 7

[0176] The difference between this comparative example and Example 2 is that the number of added antioxidants is 3 parts.

[0177] Comparative Example 8

[0178] The difference between this comparative example and Example 2 is that the number of catalysts is 1.

[0179] Comparative Example 9

[0180] The difference between this comparative example and Example 2 is that the amount of the leveling agent is 3.5 parts.

[0181] Comparative Example 10

[0182] The difference between this comparative example and Example 2 is that no leveling agent is added.

[0183] Test Case

[0184] The protective films prepared in the examples and comparative examples were subjected to Glass 20min peeling force, Glass aging peeling force, light transmittance, adhesion, film tearing voltage, high temperature and high humidity test and laser cutting simulation test to evaluate their performance in various aspects.

[0185] Glass 20min peeling force and Glass aging peeling force: refer to GB / T2792-1998;

[0186] Light transmittance and haze: refer to JIS K7136;

[0187] Adhesion: Refer to GB / T 13217.7-2023; the grade standards are shown in Table 1:

[0188] Table 1 Classification of experimental results

[0189]

[0190] The test method for dynamic voltage of fast film tearing is as follows: the protective film is attached to TFE, and a Trek520 electrostatic meter is held. The distance between the TFE object and the desktop is greater than 30cm. The protective film is torn off by hand at a speed of greater than 30cm / s. The voltage is tested with an electrostatic meter during the film tearing process. The maximum absolute value of the voltage during the film tearing process is finally recorded as the target data.

[0191] High temperature and high humidity test: 85℃*85%RH humidity oven, bubble test, use a strong flashlight to observe whether there is precipitation on the TP surface, X: indicates white fog and dirt on the whole surface; ▲: partial white fog and dirt; ▲+: obvious fog in the bubble circle; ▲-: slight fog in the bubble circle; 0: no appearance abnormality;

[0192] Laser cutting simulation: CO2 laser cutting equipment. 0: qualified; ×: unqualified.

[0193] The results are shown in Table 2 below:

[0194] Table 2

[0195]

[0196] Through testing, it was found that the present invention ensures the basic weather resistance of the colloid by matching appropriate polyester, polyether and polycarbonate, improves the adaptability of the material in laser half-cutting by antioxidants, further enhances the cross-linking degree and antioxidant performance of the material, and makes the material more stable, which can take into account both laser half-cutting and laser full-cutting processes. However, the aging viscosity of Comparative Example 1 is relatively high, and there will be obvious white fog in the bubble circle in the high temperature and high humidity test; the haze of Comparative Example 3 rises sharply and the adhesion is poor; the small molecules in Comparative Example 5 precipitate white fog; the adhesion of Comparative Example 6 laser half-cutting rubber wire deteriorates; the haze of Comparative Example 7 increases significantly, and the actual test at high temperature and high humidity deteriorates; the tearing voltage of Comparative Example 9 deteriorates, and the high temperature and high humidity test deteriorates.

[0197] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A polyurethane adhesive for laser half-cutting, characterized in that: By weight, it includes the following components: The antioxidant is selected from 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and / or 2,2'-thiobis[ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

2. The polyurethane adhesive for laser half-cutting according to claim 1, characterized in that: The polyurethane glue is prepared from polycarbonate polyol, polyether polyol and polyester polyol in a mass ratio of (60-90):(10-30):(1-10); and / or, the polycarbonate polyol is a difunctional and / or trifunctional polycarbonate polyol; the polycarbonate polyol has a number average molecular weight of 3000 to 30000, a hydroxyl value of 10 to 50 mgKOH / g, and a viscosity of 10000 to 40000 cps at 21 to 25°C; And / or, the polyether polyol is a difunctional and / or trifunctional polyether polyol; the polyether polyol has a number average molecular weight of 400 to 4000, a hydroxyl value of 34 to 88 mgKOH / g, and a viscosity of 50 to 600 cps at 21 to 25°C; And / or, the polyester polyol is a difunctional and / or trifunctional polyester polyol; the polyester polyol has a number average molecular weight of 300-4000, a hydroxyl value of 34-88 mgKOH / g, and a viscosity of 2000-30000 cps at 21-25°C.

3. The polyurethane adhesive for laser half-cutting according to claim 1, characterized in that: The curing agent is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

4. The polyurethane adhesive for laser half-cutting according to claim 1, characterized in that: The antistatic agent is selected from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide salt and / or lithium bis(trifluoromethylsulfonyl)imide.

5. The polyurethane adhesive for laser half-cutting according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate; And / or, the surfactant is an organic silicon leveling agent, and preferably the leveling agent is BYK330.

6. A polyurethane protective film for laser half-cutting, characterized in that: From top to bottom, they are a release film layer, a polyurethane adhesive layer for laser half-cutting, and a substrate layer; the polyurethane adhesive layer for laser half-cutting comprises the polyurethane adhesive for laser half-cutting described in any one of claims 1-5.

7. The polyurethane protective film for laser half-cutting according to claim 6, characterized in that: The substrate layer includes one or more of a polyurethane coating, a PET substrate and an antistatic coating; and / or, the thickness of the substrate layer is 50-125 μm; And / or, the release film layer is a PET single silicon release film with a thickness of 12-125 μm and a release force of 10-60 g / 25 mm; And / or, the release film is a single-sided or double-sided antistatic release film, and the impedance value is 10 4 ~10 9 Ω; And / or, the thickness of the polyurethane adhesive layer for laser half-cutting is 50-100 μm; And / or, the impedance of the polyurethane adhesive layer for laser half cutting is 10 6 ~10 11 Ω.

8. A method for preparing the polyurethane protective film for laser half-cutting as claimed in claim 6 or 7, characterized in that: The following steps are involved: 1) polyurethane glue, curing agent, antistatic agent, antioxidant, catalyst and surfactant are mixed uniformly according to a proportion, and the solvent is added to make the solid content of the polyurethane glue solution be 30%-50% to prepare the polyurethane glue solution for laser half cutting; 2) coating the polyurethane adhesive for laser half-cutting obtained in step 1) on the substrate layer, compounding with the release film after drying, rolling up, and aging to obtain the polyurethane protective film for laser half-cutting.

9. The preparation method according to claim 8, characterized in that: The solvent is one or a mixture of at least two of ethyl acetate, toluene, butanone, and xylene; And / or, the drying temperature is 80-120°C; And / or, the aging temperature is 40-50° C., and the aging time is 60-84 hours.

10. Use of the polyurethane adhesive for laser half-cutting described in any one of claims 1 to 5 or the polyurethane protective film for laser half-cutting described in claim 6 or 7 in the manufacturing process of OLED screens.

Images