High-temperature-resistant and high-humidity-resistant protective film adaptive to printing ink and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant and high-humidity-resistant protective film adaptive to printing ink and a preparation method thereof, and belongs to the technical field of polyurethane protective films. The high-temperature-resistant and high-humidity-resistant protective film adaptive to the printing ink is sequentially provided with a base material layer, an acrylic acid modified polyurethane adhesive layer and a release film layer from top to bottom, the acrylic acid modified polyurethane adhesive layer comprises the following components in parts by weight: 100 parts of polyurethane resin, 10-20 parts of acrylic resin, 5-20 parts of a curing agent, 0.1-2 parts of an antistatic agent and 0.1-2 parts of a catalyst; wherein the polyurethane glue is prepared from polycarbonate polyol and polyether polyol according to the mass ratio of (60 to 80): (20 to 40). The high-temperature-resistant and high-humidity-resistant protective film does not react when being attached to a printing ink area at high temperature and high humidity, is good in hydrolysis resistance, does not have rime fog after being subjected to a 85 DEG C * 85% RH humidity test for 240 hours, and is low in aging climbing and easy to uncover after being subjected to a high-temperature and high-humidity test; and the exhaust performance is good, the segment difference landfill performance is good, and bubbles are not prone to being generated at high temperature and high humidity.

Description

Technical Field

[0001] This invention relates to the field of polyurethane protective film technology, and in particular to a high-temperature and high-humidity resistant protective film adapted to inks and its preparation method. Background Technology

[0002] Automotive TP (Transparent Plate) includes different areas to be applied, such as the viewing area, IR hole ink, and QR code ink. Some automotive TP involves overseas shipments and container transportation, which are subject to high temperature and humidity, requiring higher weather resistance of the protective film and that it does not react with the ink at high temperatures.

[0003] Silicone-based protective films are prone to silicone transfer, affecting product appearance. Acrylic-based protective films are prone to powder shedding during die-cutting and have poor air release properties, which is not conducive to customer use. Polyurethane (PU) protective films on the market have made some breakthroughs in the glass ring test of the viewing area, but they have poor compatibility with the ink area and cannot be universally used. Developing a PU protective film that is universally applicable to both the ink area and the viewing area is of certain significance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a high-temperature and high-humidity resistant protective film adapted to inks and its preparation method. The acrylic-modified polyurethane adhesive used in the protective film of this invention, while ensuring good peel strength, light transmittance, and haze, exhibits better heat resistance, hydrolysis resistance, and does not react with inks. It can withstand prolonged high-temperature and high-humidity environmental testing without white haze or ring marks.

[0005] The first objective of this invention is to provide a high-temperature and high-humidity resistant protective film adapted to inks, wherein the high-temperature and high-humidity resistant protective film adapted to inks is configured from top to bottom as a substrate layer, an acrylic modified polyurethane adhesive layer, and a release film layer.

[0006] By weight, the acrylic-modified polyurethane adhesive layer comprises the following components:

[0007] 100 parts of polyurethane adhesive;

[0008] 10-20 parts acrylic resin;

[0009] 5-10 parts of curing agent;

[0010] 0.1-2 parts of antistatic agent;

[0011] Catalyst 0.1-2 parts;

[0012] The polyurethane adhesive is prepared from polycarbonate polyol and polyether polyol in a mass ratio of (60~80):(20~40).

[0013] Specifically, the acrylic-modified polyurethane adhesive layer comprises, by weight, the following components:

[0014] The polyurethane resin is in parts by weight of 100.

[0015] The acrylic resin is in parts by weight of 10-20 parts, for example, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts or 20 parts, etc.

[0016] The curing agent is in parts by weight of 5-10 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts, etc.

[0017] The antistatic agent is present in parts by weight of 0.1-2 parts, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts, etc.

[0018] The catalyst is present in parts by weight of 0.1-2 parts, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts, etc.

[0019] The polyurethane adhesive is prepared from polycarbonate polyol and polyether polyol in a mass ratio of (60~80):(20~40).

[0020] In one embodiment of the present invention, the polycarbonate polyol is a trifunctional polycarbonate polyester.

[0021] Preferably, the number average molecular weight of the polycarbonate polyol is 2000-4000, for example, 2000, 2500, 3000, 3500 or 4000; the hydroxyl value is 34-88 mgKOH / g, for example, 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;

[0022] In one embodiment of the present invention, the polyether polyol is a difunctional and / or trifunctional polyether polyol.

[0023] Preferably, the polyether polyol has a number average molecular weight of 400-4000, such as 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, or 4000; and a hydroxyl value of 34-88 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.

[0024] If the hydroxyl values ​​of polycarbonate polyols and polyether polyols are not within the above ratio range, the film-forming properties will be poor.

[0025] In one embodiment of the present invention, the acrylic resin is a mixture of hydroxyethyl methacrylate (HEMA), cyclohexyl methacrylate (CHMA), and lauryl methacrylate (LMA); wherein HEMA accounts for 40-50 wt%, CHMA accounts for 30-40 wt%, and LMA accounts for 10-30 wt%.

[0026] In one embodiment of the present invention, the curing agent is a polymer of isophorone diisocyanate; the curing agent is one or more of isophorone diisocyanate dimer, isophorone diisocyanate trimer, isophorone diisocyanate pentamer and isophorone diisocyanate heptamer.

[0027] In one embodiment of the present invention, the antistatic agent is any one or a mixture of at least two of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, lithium bis(trifluoromethanesulfonyl)imide, and lithium bis(trifluoromethanesulfonyl)imide.

[0028] In one embodiment of the present invention, the substrate layer is a PET film, a single-sided antistatic PET, or a double-sided antistatic PET.

[0029] Preferably, the thickness of the substrate layer is 12-125 μm, for example, 12 μm, 20 μm, 30 μm, 40 μm, 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 11 Ω, for example, 10 4 Ω, 10 5 Ω, 10 6 Ω, 107 Ω, 10 8 Ω, 10 9 Ω, 10 10 Ω, 10 11 Ω, etc.

[0030] Preferably, the release film layer is a PET monosilicone release film with a thickness of 12-125 μm, such as 12 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 125 μm, etc.; and a release force of 10-30 g / 25mm, such as 10 g / 25mm, 11 g / 25mm, 12 g / 25mm, 13 g / 25mm, 14 g / 25mm, 15 g / 25mm, 16 g / 25mm, 17 g / 25mm, 18 g / 25mm, 19 g / 25mm, 20 g / 25mm, 21 g / 25mm, 22 g / 25mm, 23 g / 25mm, 24 g / 25mm, 25 g / 25mm, 26 g / 25mm, etc. g / 25mm, 27 g / 25mm, 28 g / 25mm, 29 g / 25mm or 30 g / 25mm, etc.

[0031] Preferably, the release film is a single-sided or double-sided antistatic release film with an impedance value of 10. 4 ~10 11 Ω, for example, 10 4 Ω, 10 5 Ω, 10 6 Ω, 10 7 Ω, 10 8 Ω, 10 9 Ω, 10 10 Ω, 10 11 Ω, etc.

[0032] The second objective of this invention is to provide a method for preparing the high-temperature and high-humidity resistant protective film for inks, comprising the following steps:

[0033] 1) According to the formula, mix polyurethane adhesive, acrylic resin, curing agent, antistatic agent and catalyst in solvent evenly to prepare acrylic modified polyurethane adhesive;

[0034] 2) The acrylic-modified polyurethane adhesive obtained in step 1) is coated on the substrate layer, dried, and then laminated with the release film, wound up, and cured to obtain the high temperature and high humidity resistant protective film for the ink.

[0035] Preferably, the drying temperature is 80~120℃, for example, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃ or 120℃.

[0036] Preferably, the curing temperature is 40-50℃, for example, 40℃, 41℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃, 49℃, or 50℃; the curing 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.

[0037] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0038] This invention provides a high-temperature and high-humidity resistant protective film adapted to inks (structural schematic diagram shown). Figure 1 (As shown) and its preparation method. The acrylic-modified polyurethane adhesive of this invention uses polycarbonate polyol as the main material in combination with polyether polyol. The acrylic resin is used to synthesize a modified polyurethane resin, which has better mechanical properties, scratch resistance, and acid and alkali resistance compared to materials synthesized from traditional polyether polyols. It also has better hydrolysis resistance compared to polyester polyols. HEMA resin contains hydroxyl functional groups, which can crosslink with NCO functional groups in polyurethane resin to enhance solubility. CHMA contains a cyclic rigid structure, which improves the material's hardness and heat resistance, and has a certain steric hindrance effect, reducing the active sites that can react with inks. LMA resin has a long-chain structure that enhances the material's toughness and also has strong hydrophobicity, which can improve the poor water resistance of polyurethane resin. It has little impact on the initial tack and aging tack of polyurethane, and will not cause problems such as difficulty in peeling or inability to peel after high temperature and high humidity. Specifically, the peel force between the protective film and SUS304 for 20 minutes is 0.5-1.5. g / 25mm, light transmittance >88%, haze <2.5%, no precipitation or white haze ring mark in 60℃*95%RH*240h environmental test, ink color change; no precipitation or white haze ring mark in 85℃*85%RH*240h environmental test, ink color change; peel strength ≤3g after aging in 85℃*85%RH*240h. Attached Figure Description

[0039] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0040] Figure 1This is a schematic diagram of the structure of the high-temperature and high-humidity protective film adapted to inks of the present invention. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0043] The CAS number of cyclohexyl methacrylate used in all the following embodiments and comparative examples of the present invention is 868-77-9; the CAS number of lauryl methacrylate is 142-90-5; and the CAS number of cyclohexyl methacrylate is 101-43-9.

[0044] The isophorone diisocyanate trimer curing agent was purchased from Covestro under the brand name Desmodur C.

[0045] The lithium bis(trifluoromethanesulfonyl)imide was purchased from Guotai Chaowei, with the grade CF1117.

[0046] Dibutyltin dilaurate was purchased from Hangzhou Silicon Machinery Co., Ltd., with the grade HG-0111.

[0047] The hexamethylene diisocyanate (HDI) trimer curing agent was purchased from Asahi Kasei Corporation under the brand name TPA-100.

[0048] Example 1

[0049] This embodiment provides a high-temperature and high-humidity resistant protective film adapted to inks, comprising, from top to bottom, a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. Specifically, the substrate layer is a 50 μm PET film; the acrylic-modified polyurethane adhesive layer has the following components:

[0050] 100 parts of polyurethane adhesive: polymerized from polycarbonate polyol and polyether polyol at a mass ratio of 60:40; wherein, the polycarbonate polyol was purchased from Ube Industries, Ltd., UH-300, with a number average molecular weight of 3000 and a hydroxyl value of 34-40; and the polyether polyol was purchased from Guodu Chemical, DP2000E, with a number average molecular weight of 2000 and a hydroxyl value of 53-58.

[0051] 15 parts acrylic resin (HEMA:CHMA:LMA in a mass ratio of 4:4:2).

[0052] Trimeric curing agent of 8 parts isophorone diisocyanate;

[0053] 0.5 parts antistatic agent (lithium bis(trifluoromethanesulfonyl)imide);

[0054] 0.3 parts catalyst (dibutyltin dilaurate);

[0055] Ethyl acetate was added as a diluent to bring the solid content to 25%; the acrylic-modified polyurethane adhesive was prepared by dispersion.

[0056] The release film layer is a PET monosilicone release film with a thickness of 50 μm and a release force of 20 g / 25 mm.

[0057] The preparation method of the above-mentioned high-temperature and high-humidity resistant protective film for compatible inks includes the following steps:

[0058] (1) The polyurethane adhesive, acrylic resin, curing agent, antistatic agent, plasticizer, catalyst and diluent are mixed and stirred at room temperature for 30 min to obtain a mixture, thus obtaining acrylic modified polyurethane adhesive.

[0059] (2) The acrylic modified polyurethane adhesive is coated on the substrate layer, dried at 120°C to a thickness of 10μm, then laminated with a release film, wound up, and cured at 45°C for 72 h to obtain the high temperature and high humidity resistant protective film for the ink.

[0060] Example 2

[0061] This embodiment provides a high-temperature and high-humidity resistant protective film adapted to inks, comprising, from top to bottom, a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. Specifically, the substrate layer is a 50 μm PET film; the acrylic-modified polyurethane adhesive layer has the following components:

[0062] 100 parts of polyurethane adhesive: polymerized from polycarbonate polyol and polyether polyol at a mass ratio of 70:30; wherein, the polycarbonate polyol was purchased from Ube Industries, Ltd., UH-300, with a number average molecular weight of 3000 and a hydroxyl value of 34-40; the polyether polyol was purchased from Guodu Chemical, DP2000E, with a number average molecular weight of 2000 and a hydroxyl value of 53-58;

[0063] 15 parts acrylic resin (HEMA:CHMA:LMA in a mass ratio of 4:4:2).

[0064] Trimeric curing agent of 8 parts isophorone diisocyanate;

[0065] 0.5 parts antistatic agent (lithium bis(trifluoromethanesulfonyl)imide);

[0066] 0.3 parts catalyst (dibutyltin dilaurate);

[0067] Ethyl acetate was added as a diluent to bring the solid content to 25%; the acrylic-modified polyurethane adhesive was prepared by dispersion.

[0068] The release film layer is a PET monosilicone release film with a thickness of 50 μm and a release force of 20 g / 25 mm.

[0069] The preparation method of the above-mentioned high-temperature and high-humidity resistant protective film for compatible inks includes the following steps:

[0070] (1) The polyurethane adhesive, acrylic resin, curing agent, antistatic agent, plasticizer, catalyst and diluent are mixed and stirred at room temperature for 30 min to obtain a mixture, thus obtaining acrylic modified polyurethane adhesive.

[0071] (2) The acrylic modified polyurethane adhesive is coated on the substrate layer, dried at 120°C to a thickness of 10μm, then laminated with a release film, wound up, and cured at 45°C for 72 h to obtain the high temperature and high humidity resistant protective film for the ink.

[0072] Example 3

[0073] This embodiment provides a high-temperature and high-humidity resistant protective film adapted to inks, comprising, from top to bottom, a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. Specifically, the substrate layer is a 50μm PET film; the acrylic-modified polyurethane adhesive layer has the following components:

[0074] 100 parts of polyurethane adhesive: polymerized from polycarbonate polyol and polyether polyol at a mass ratio of 80:20; wherein, the polycarbonate polyol was purchased from Ube Industries, Ltd., UH-300, with a number average molecular weight of 3000 and a hydroxyl value of 34-40; the polyether polyol was purchased from Guodu Chemical, DP2000E, with a number average molecular weight of 2000 and a hydroxyl value of 53-58;

[0075] 15 parts acrylic resin (HEMA:CHMA:LMA in a mass ratio of 4:4:2).

[0076] Trimeric curing agent of 8 parts isophorone diisocyanate;

[0077] 0.5 parts antistatic agent (lithium bis(trifluoromethanesulfonyl)imide);

[0078] 0.3 parts catalyst (dibutyltin dilaurate);

[0079] Ethyl acetate was added as a diluent to bring the solid content to 25%; the acrylic-modified polyurethane adhesive was prepared by dispersion.

[0080] The release film layer is a PET monosilicone release film with a thickness of 50 μm and a release force of 20 g / 25 mm.

[0081] The preparation method of the above-mentioned high-temperature and high-humidity resistant protective film for compatible inks includes the following steps:

[0082] (1) The polyurethane adhesive, acrylic resin, curing agent, antistatic agent, plasticizer, catalyst and diluent are mixed and stirred at room temperature for 30 min to obtain a mixture, thus obtaining acrylic modified polyurethane adhesive.

[0083] (2) The acrylic modified polyurethane adhesive is coated on the substrate layer, dried at 120°C to a thickness of 10μm, then laminated with a release film, wound up, and cured at 45°C for 72 h to obtain the high temperature and high humidity resistant protective film for the ink.

[0084] Example 4

[0085] This embodiment provides a high-temperature and high-humidity resistant protective film adapted to inks, comprising, from top to bottom, a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. Specifically, the substrate layer is a 50μm PET film; the acrylic-modified polyurethane adhesive layer has the following components:

[0086] 100 parts of polyurethane adhesive: polymerized from polycarbonate polyol and polyether polyol at a mass ratio of 70:30; wherein, the polycarbonate polyol was purchased from Ube Industries, Ltd., UH-300, with a number average molecular weight of 3000 and a hydroxyl value of 34-40; the polyether polyol was purchased from Guodu Chemical, DP2000E, with a number average molecular weight of 2000 and a hydroxyl value of 53-58;

[0087] 10 parts acrylic resin (HEMA:CHMA:LMA in a mass ratio of 4:4:2).

[0088] Trimeric curing agent of 6 parts isophorone diisocyanate;

[0089] 0.5 parts antistatic agent (lithium bis(trifluoromethanesulfonyl)imide);

[0090] 0.3 parts catalyst (dibutyltin dilaurate);

[0091] Ethyl acetate was added as a diluent to bring the solid content to 25%; the acrylic-modified polyurethane adhesive was prepared by dispersion.

[0092] The release film layer is a PET monosilicone release film with a thickness of 50 μm and a release force of 20 g / 25 mm.

[0093] The preparation method of the above-mentioned high-temperature and high-humidity resistant protective film for compatible inks includes the following steps:

[0094] (1) The polyurethane adhesive, acrylic resin, curing agent, antistatic agent, plasticizer, catalyst and diluent are mixed and stirred at room temperature for 30 min to obtain a mixture, thus obtaining acrylic modified polyurethane adhesive.

[0095] (2) The acrylic modified polyurethane adhesive is coated on the substrate layer, dried at 120°C to a thickness of 10μm, then laminated with a release film, wound up, and cured at 45°C for 72 h to obtain the high temperature and high humidity resistant protective film for the ink.

[0096] Example 5

[0097] This embodiment provides a high-temperature and high-humidity resistant protective film adapted to inks, comprising, from top to bottom, a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. Specifically, the substrate layer is a 50 μm PET film; the acrylic-modified polyurethane adhesive layer has the following components:

[0098] 100 parts of polyurethane adhesive: polymerized from polycarbonate polyol and polyether polyol at a mass ratio of 70:30; wherein, the polycarbonate polyol was purchased from Ube Industries, Ltd., UH-300, with a number average molecular weight of 3000 and a hydroxyl value of 34-40; the polyether polyol was purchased from Guodu Chemical, DP2000E, with a number average molecular weight of 2000 and a hydroxyl value of 53-58;

[0099] 20 parts acrylic resin (HEMA:CHMA:LMA in a mass ratio of 4:4:2).

[0100] 10 parts of isophorone diisocyanate trimer curing agent;

[0101] 0.5 parts antistatic agent (lithium bis(trifluoromethanesulfonyl)imide);

[0102] 8 parts plasticizer (DOTP);

[0103] 0.3 parts catalyst (dibutyltin dilaurate);

[0104] Ethyl acetate was added as a diluent to bring the solid content to 25%; the acrylic-modified polyurethane adhesive was prepared by dispersion.

[0105] The release film layer is a PET monosilicone release film with a thickness of 50 μm and a release force of 20 g / 25 mm.

[0106] The preparation method of the above-mentioned high-temperature and high-humidity resistant protective film for compatible inks includes the following steps:

[0107] (1) The polyurethane adhesive, acrylic resin, curing agent, antistatic agent, plasticizer, catalyst and diluent are mixed and stirred at room temperature for 30 min to obtain a mixture, thus obtaining acrylic modified polyurethane adhesive.

[0108] (2) The acrylic modified polyurethane adhesive is coated on the substrate layer, dried at 120°C to a thickness of 10μm, then laminated with a release film, wound up, and cured at 45°C for 72 h to obtain the high temperature and high humidity resistant protective film for the ink.

[0109] Comparative Example 1

[0110] This comparative example provides a protective film, similar to Example 2, except that the mass ratio of polycarbonate polyol to polyether polyol in the polyurethane adhesive of the acrylic modified polyurethane layer is 50:50, and the remaining steps are the same as in Example 2.

[0111] The preparation method of the above protective film is consistent with that in Example 2.

[0112] Comparative Example 2

[0113] This comparative example provides a protective film, similar to Example 1, except that the polyurethane adhesive in the acrylic-modified polyurethane layer contains only polycarbonate polyol and not polyether polyol. The isophorone diisocyanate trimer curing agent is 10 parts, the antistatic agent is 1 part, and the catalyst is 0.8 parts; the remaining steps are consistent with Example 1.

[0114] The preparation method of the above protective film is consistent with that in Example 1.

[0115] Comparative Example 3

[0116] This comparative example provides a protective film, similar to Example 2, except that: the acrylic resin in the polyurethane adhesive of the acrylic-modified polyurethane adhesive layer is 5 parts, and the remaining steps are the same as in Example 2.

[0117] The preparation method of the above protective film is consistent with that in Example 2.

[0118] Comparative Example 4

[0119] This comparative example provides a protective film, similar to Example 2, except that the acrylic resin in the polyurethane adhesive of the acrylic-modified polyurethane adhesive layer is 25 parts, and the remaining steps are the same as in Example 2.

[0120] The preparation method of the above protective film is consistent with that in Example 2.

[0121] Comparative Example 5

[0122] This comparative example provides a protective film, similar to Example 2, except that the isophorone diisocyanate trimer curing agent in the polyurethane adhesive of the acrylic modified polyurethane layer is replaced with curing agent HDI, and the remaining steps are consistent with Example 2.

[0123] The preparation method of the above protective film is consistent with that in Example 2.

[0124] Comparative Example 6

[0125] This comparative example provides a protective film, similar to Example 1, except that no plasticizer is added, and the remaining steps are the same as in Example 1.

[0126] The preparation method of the above protective film is consistent with that in Example 1.

[0127] Comparative Example 7

[0128] This comparative example provides a protective film, similar to Example 2, except that: the mass ratio of polycarbonate polyol to polyether polyol in the polyurethane adhesive of the acrylic modified polyurethane layer is 50:50, and the trimer curing agent of isophorone diisocyanate is 10 parts, while the remaining steps are consistent with Example 2.

[0129] The preparation method of the above protective film is consistent with that in Example 2.

[0130] Comparative Example 8

[0131] This comparative example provides a protective film, similar to Example 2, except that: the mass ratio of polycarbonate polyol to polyether polyol in the polyurethane adhesive of the acrylic modified polyurethane layer is 50:50, and the trimer curing agent of isophorone diisocyanate is 12 parts, while the remaining steps are consistent with Example 2.

[0132] The preparation method of the above protective film is consistent with that in Example 2.

[0133] Comparative Example 9

[0134] This comparative example provides a protective film, similar to Example 1, except that the polyurethane adhesive in the acrylic-modified polyurethane layer contains only polycarbonate polyol and not polyether polyol. The isophorone diisocyanate trimer curing agent is 10 parts, the catalyst is 0.8 parts, and the remaining steps are consistent with Example 1.

[0135] The preparation method of the above protective film is consistent with that in Example 1.

[0136] Comparative Example 10

[0137] This comparative example provides a protective film, similar to Example 1, except that the polyurethane adhesive in the acrylic-modified polyurethane layer contains only polycarbonate polyol and not polyether polyol. The isophorone diisocyanate trimer curing agent is 12 parts, the catalyst is 0.8 parts, and the remaining steps are consistent with Example 1.

[0138] The preparation method of the above protective film is consistent with that in Example 1.

[0139] Performance testing

[0140] The protective films prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to performance tests, and the test results are shown in Table 1.

[0141] SUS peel strength test method: Refer to GB / T2792-1998 standard, apply a 25mm wide protective film, peel off at ∠180° after 20 minutes, at an environment of 23℃ and 65%RH;

[0142] Aging peel strength: According to GB / T2792-1998 standard, a 25mm wide protective film is applied, and after cooling for 30 minutes at 80℃ for 72 hours, it is peeled off at ∠180° in an environment of 23℃ and 65%RH.

[0143] Exhaust performance: 100 mm × 100 mm sample, attached to glass for testing, timed with a stopwatch;

[0144] Film peeling voltage: Equipment: Trek520; Item to be peeled: Vehicle TP;

[0145] IR aperture ink reaction: Baking at 60℃ for 24 hours; Subject: Automotive TP;

[0146] High temperature and high humidity environmental test 1: Oven; Visual inspection; Attached object: Vehicle-mounted TP; 60℃*90%RH*240h;

[0147] High temperature and high humidity environmental test 2: Oven; visual inspection; Attached object: vehicle TP; 85℃*85%RH*240h.

[0148] Table 1

[0149]

[0150] As can be seen from Table 1, the acrylic-modified polyurethane protective film of the present invention, while ensuring good peel strength, aging peel strength and tear voltage, can not react with IR hole ink, and at the same time, it can also ensure no pollution during high temperature and high humidity testing.

[0151] Comparative Examples 7 and 8 further increased the amount of curing agent added compared to Comparative Example 1, fully demonstrating that when the polyether content is too high, the problem of white fog and ink reaction cannot be solved by adjusting the degree of crosslinking.

[0152] Comparative Examples 9, 10, and 2 together illustrate that when the polyester content is excessive, the aging viscosity is too high (further increasing the curing agent has no effect on improving the aging viscosity), the peeling voltage is too high, and the addition of antistatic agent has a weak effect on improving the peeling voltage.

[0153] 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 high-temperature and high-humidity resistant protective film adapted to inks, characterized in that, The high-temperature and high-humidity protective film for the adaptable ink is configured from top to bottom as a substrate layer, an acrylic-modified polyurethane adhesive layer, and a release film layer. By weight, the acrylic-modified polyurethane adhesive layer comprises the following components: 100 parts of polyurethane adhesive; 10-20 parts acrylic resin; 5-10 parts of curing agent; 0.1-2 parts of antistatic agent; Catalyst 0.1-2 parts; The polyurethane adhesive is prepared from polycarbonate polyol and polyether polyol in a mass ratio of (60~80):(20~40).

2. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The polycarbonate polyol is a trifunctional polycarbonate polyester. And / or, the polycarbonate polyol has a number average molecular weight of 2000~4000, a hydroxyl value of 34~88 mg KOH / g, and a viscosity of 100-40000 cps at 21-25℃; And / or, the polyether polyol is a difunctional and / or trifunctional polyether polyol; And / or, the polyether polyol has a number average molecular weight of 400-4000, a hydroxyl value of 34-88 mgKOH / g, and a viscosity of 50-600 cps at 21-25°C.

3. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The acrylic resin is a mixture of hydroxyethyl methacrylate, cyclohexyl methacrylate and lauryl methacrylate; wherein hydroxyethyl methacrylate accounts for 40-50 wt%, cyclohexyl methacrylate accounts for 30-40 wt%, and lauryl methacrylate accounts for 10-30 wt%.

4. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The curing agent is a polymer of isophorone diisocyanate.

5. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The antistatic agent is one or more of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, lithium bis(trifluoromethanesulfonyl)imide, and lithium bis(trifluoromethanesulfonyl)imide.

6. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The plasticizer is one or more of DOTP, IPP and ATBC.

7. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate.

8. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The substrate layer is PET film, single-sided antistatic PET, or double-sided antistatic PET. And / or, the thickness of the substrate layer is 12-125 μm, and the antistatic surface impedance value of the single-sided antistatic PET or the double-sided antistatic PET is independently 10. 4 ~10 11 Ω; And / or, the release film layer is a PET single-silicone release film with a thickness of 12-125μm and a release force of 10-30g / 25mm; And / or, the release film is a single-sided or double-sided antistatic release film with an impedance value of 10. 4 ~10 11 Ω.

9. The high-temperature and high-humidity resistant protective film according to claim 1, characterized in that, The acrylic-modified polyurethane adhesive layer has a thickness of 5-80 μm and an impedance value of 10. 6 ~10 12 Ω.

10. The method for preparing a high-temperature and high-humidity resistant protective film for inks according to claims 1-9, characterized in that, Includes the following steps: 1) According to the formula, mix polyurethane adhesive, acrylic resin, curing agent, antistatic agent and catalyst in solvent evenly to prepare acrylic modified polyurethane adhesive; 2) The acrylic-modified polyurethane adhesive obtained in step 1) is coated on the substrate layer, dried, and then laminated with the release film, wound up, and cured to obtain the high temperature and high humidity resistant protective film for the ink.

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