High-temperature-resistant and imaging-stable thermal medical film and preparation process thereof

Abstract

The present application relates to the field of film, specifically to a kind of high-temperature-resistant thermal medical film with stable imaging and its preparation process, introduce alumina phase in silica aerogel, modify silica aerogel doped with alumina phase with amino hetero naphthalene diphenyl poly aryl ether ketone;In order to give back layer, protective layer excellent mechanical damage resistance, make it after suffering mechanical scratch, self-repair at room temperature, restore excellent hydrophobicity, high temperature resistance, antistatic property, introduce self-repairing polyurethane in back layer and protective layer, with polypropylene carbonate glycol as soft segment, with isophorone diisocyanate as hard segment, 4,4'-dithiodiphenylamine, 4-hydroxyphenylboric acid as chain extender to synthesize self-repairing polyurethane;Epoxy silicone resin is used as the base coating of back layer and protective layer, introduce silicone slip agent in back layer, so that back layer has long-acting stable and non-migratory slip property.

Description

Technical Field

[0001] This invention relates to the field of film, specifically to an imaging-stable, high-temperature resistant, heat-sensitive medical film and its preparation process. Background Technology

[0002] With the development of medical technology, medical films are constantly being updated. The current mainstream medical film is dry medical digital film, which is a thermal information recording material. It is formed by physical and chemical changes caused by changes in thermal energy. The process is simple and environmentally friendly.

[0003] Existing thermal medical films generally consist of a backing layer, a support, an imaging layer, and a protective film. The imaging layer and backing layer are distributed on both sides of the support, which serves as a carrier and support, while the protective film and backing layer assist in imaging. Polyester film-based supports are typically used, with organic thermal coatings for imaging. However, this method suffers from poor adhesion between the film base and the thermal imaging layer, as well as poor antistatic properties, leading to film adhesion during printing. In contact printing, the film needs high temperature and pressure resistance to ensure stable imaging, and good water resistance to prevent moisture absorption and ensure clear color development of the imaging layer. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature resistant, thermosensitive medical film with stable imaging and its preparation process, so as to solve the problems in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A process for preparing a high-temperature resistant, thermosensitive medical film with stable imaging includes the following steps:

[0007] S1: A back coating liquid is prepared using composite silica, slip agent, self-healing polyurethane, and epoxy silicone resin;

[0008] S2: An imaging layer coating solution was prepared using colorimetric microcapsules, dye microcapsules, and epoxy silicone resin;

[0009] S3: A protective coating is prepared using composite silica, self-healing polyurethane, and epoxy silicone resin.

[0010] S4: A backing coating is applied to one side of a polyester film base, and an imaging layer coating and a protective coating are applied to the other side in sequence. The film is then heat-set and wound up to obtain a high-temperature resistant, heat-sensitive medical film with stable imaging.

[0011] Furthermore, by weight, the composition of the back coating liquid is as follows: 2-4 parts of composite silica, 1-3 parts of slip agent, 12-16 parts of self-healing polyurethane, and 21-25 parts of epoxy silicone resin.

[0012] Furthermore, by mass, the composition of the imaging layer coating is: 17-21 parts of colorimetric microcapsules, 3-7 parts of dye microcapsules, and 33-36 parts of epoxy silicone resin.

[0013] Furthermore, by weight, the protective coating consists of: 1-3 parts composite silica, 10-15 parts self-healing polyurethane, and 20-25 parts epoxy silicone resin.

[0014] Furthermore, the preparation of composite silica includes the following steps:

[0015] (1) Under a nitrogen atmosphere, 4-(4-hydroxyphenyl)-2,3-diazanaphthalene-1-one, 4,4'-difluorobenzophenone, potassium carbonate, dimethyl sulfoxide and toluene were mixed, heated to 135-140℃ and kept at 2-3h, heated to 150-160℃ and kept at 20-30min, heated to 175℃ and kept at 1h, cooled to 18-25℃ and added a mixture of 4-aminophenol, potassium carbonate, dimethyl sulfoxide and toluene, heated to 140℃ and kept at 3h, heated to 165℃ and kept at 3h, washed with water until neutral, filtered, washed successively with anhydrous ethanol and deionized water until the filtrate was neutral, dried to obtain amino-naphthalene-biphenyl polyarylether ketone;

[0016] (2) Mix tetraethyl silicate, deionized water and ethanol, add nitric acid and stir for 2 hours, add aluminum chloride hexahydrate, ethanol and deionized water mixture and stir for 1-2 hours, add amino-naphthyl biphenyl polyarylether ketone and stir for 8-9 hours, transfer to ethanol solution of tetraethyl silicate, soak at 60°C for 48 hours, replace with ethanol, and obtain composite silica by supercritical drying with ethanol.

[0017] Furthermore, the working conditions for supercritical drying are: pressure of 8 MPa and temperature of 275℃.

[0018] Furthermore, the preparation of self-healing polyurethane includes the following steps:

[0019] Under a nitrogen atmosphere, polypropylene carbonate diol, 4,4'-dithiodiphenylamine, and N,N-dimethylformamide were mixed, and isophorone diisocyanate and dibutyltin dilaurate were added. The mixture was kept in a water bath at 80-85°C for 2-3 hours. Then, a mixture of 4-hydroxyphenylboronic acid and N,N-dimethylformamide was added, and the mixture was stirred for another 2-3 hours to obtain self-healing polyurethane.

[0020] Furthermore, the preparation of dye microcapsules includes the following steps: melamine, formaldehyde solution, and deionized water are mixed, the pH value is adjusted to 9.5, and the mixture is heated in an 80°C water bath for 40 minutes to obtain a melamine resin prepolymer; a thermosensitive dye, Span 80, and deionized water are mixed, emulsified at 12000 r / min for 25 minutes, the melamine resin prepolymer is added, the mixture is heated in a 70°C water bath for 40 minutes, the pH value is adjusted to 4, the mixture is stirred at 400 r / min for 8 hours, filtered, and dried to obtain dye microcapsules.

[0021] Furthermore, the preparation of the colorimetric microcapsules includes the following steps: melamine, formaldehyde solution, and deionized water are mixed, the pH value is adjusted to 9.5, and the mixture is heated in an 80°C water bath for 40 minutes to obtain a melamine resin prepolymer; a colorimetric agent, Span 80, and deionized water are mixed, emulsified at 12000 r / min for 25 minutes, the melamine resin prepolymer is added, the mixture is heated in a 70°C water bath for 40 minutes, the pH value is adjusted to 4, the mixture is stirred at 400 r / min for 8 hours, filtered, and dried to obtain the colorimetric microcapsules.

[0022] The beneficial effects of this invention are:

[0023] This invention provides a high-temperature resistant thermosensitive medical film with stable imaging and its preparation process. The prepared film has high high-temperature resistance, water resistance, and antistatic properties, and provides stable imaging and clear color development when used as a medical film.

[0024] The silica introduced in this invention is in aerogel form. Compared with powdered silica, aerogel has the characteristics of high specific surface area, high porosity, and low density, but it also has the disadvantage of low mechanical strength at high temperatures. This invention introduces an alumina phase into the silica aerogel, which improves the film's high-temperature resistance and gives it better antistatic properties. In the film's imaging layer, dye microcapsules and developer microcapsules are dispersed in a coating containing an adhesive. The microcapsule structure separates the developer from the dye. During printing heating, the capsule walls of the developer microcapsules rupture and penetrate into the dye. The composite silica can achieve rapid heat dissipation during printing, thereby improving the film's imaging stability and clarity. The silica aerogel doped with the alumina phase is modified with amino-naphthyl biphenyl polyaryletherketone. Amino-terminated heteronaphthyl biphenyl polyether ketones were synthesized using 4-(4-hydroxyphenyl)-2,3-diazanaphthyl-1-one, 4,4'-difluorobenzophenone, and 4-aminophenol as raw materials. The amino groups of the amino-terminated heteronaphthyl biphenyl polyether ketones were grafted onto silica aerogel doped with alumina phase, improving the uniformity of the alumina-doped silica aerogel dispersion in the back layer, while also enhancing the hydrophobicity and high-temperature resistance of the back layer and increasing the complexity of the conductive network, thereby improving the antistatic properties of the coating. Furthermore, the amino-terminated heteronaphthyl biphenyl polyether ketones in the composite silica, along with the self-healing polyurethane, simultaneously act as curing agents for the epoxy silicone resin, introducing rigid, twisted, non-coplanar heteronaphthyl biphenyl structures into the back layer and protective layer, resulting in a cured coating with excellent thermodynamic and heat resistance properties.

[0025] To impart excellent resistance to mechanical damage to the backing and protective layers, enabling them to rapidly self-repair at room temperature after mechanical scratches and restore excellent hydrophobicity and high-temperature resistance, self-healing polyurethane is introduced into the backing and protective layers. The self-healing polyurethane is synthesized using polypropylene carbonate diol as the soft segment, isophorone diisocyanate as the hard segment, and 4,4'-dithiodiphenylamine and 4-hydroxyphenylboronic acid as chain extenders. The abundant benzene ring structure and boron-oxygen six-membered ring structure impart a high crosslinking density, giving the coating good mechanical strength. The dynamic covalent boron-oxygen six-membered rings in the self-healing polyurethane, along with the metal-disulfide dynamic combination and hydrogen bonds present in the disulfide bonds and metals in the composite silica, synergistically endow the film with self-healing properties at room temperature, thereby extending the film's service life.

[0026] Epoxy silicone resin is used as the base coating for the backing and protective layers. Silicone slip agents are introduced into the backing layer to give it long-lasting, stable, and non-migrating slip properties. Composite silica is introduced into the backing and protective layers to improve the uniformity of silica dispersion in the backing and protective layers, as well as to improve the waterproofness, high temperature resistance, and antistatic properties of the backing and protective layers. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1: A preparation process for a high-temperature resistant, heat-sensitive medical film with stable imaging, comprising the following steps:

[0031] S1: A back coating liquid is prepared using composite silica, slip agent, self-healing polyurethane, and epoxy silicone resin;

[0032] The composition of the back coating liquid by mass parts is: 2 parts composite silica, 1 part slip agent, 12 parts self-healing polyurethane, and 21 parts epoxy silicone resin.

[0033] S2: An imaging layer coating solution was prepared using colorimetric microcapsules, dye microcapsules, and epoxy silicone resin;

[0034] The composition of the imaging layer coating solution by mass parts is: 17 parts of colorimetric microcapsules, 3 parts of dye microcapsules, and 33 parts of epoxy silicone resin.

[0035] S3: A protective coating is prepared using composite silica, self-healing polyurethane, and epoxy silicone resin.

[0036] The protective coating consists of the following components by weight: 1 part composite silica, 10 parts self-healing polyurethane, and 20 parts epoxy silicone resin.

[0037] The preparation of composite silica includes the following steps:

[0038] (1) Under a nitrogen atmosphere, 2.88 g of 4-(4-hydroxyphenyl)-2,3-diazanaphthalene-1-one, 2.62 g of 4,4'-difluorobenzophenone, 1.93 g of potassium carbonate, 7.5 mL of dimethyl sulfoxide, and 15 mL of toluene were mixed, heated to 135 °C and kept at that temperature for 3 h, then heated to 150 °C and kept at that temperature for 30 min, then heated to 175 °C and kept at that temperature for 1 h, then cooled to 18 °C and added a mixture of 0.78 g of 4-aminophenol, 0.7 g of potassium carbonate, 2.5 mL of dimethyl sulfoxide, and 5 mL of toluene, then heated to 140 °C and kept at that temperature for 3 h, then heated to 165 °C and kept at that temperature for 3 h, then washed with water until neutral, filtered, and washed successively with anhydrous ethanol and deionized water until the filtrate was neutral, then dried to obtain amino-naphthalene-biphenyl polyarylether ketone;

[0039] (2) Mix 0.5 mmol tetraethyl silicate, 2 mL deionized water and 6 mL ethanol, add 0.5 μL nitric acid and stir for 2 h, add 0.5 mmol aluminum chloride hexahydrate, 8 mL ethanol and 2 mL deionized water mixture and stir for 1 h, add 0.5 g amino-naphthyl biphenyl polyarylether ketone and stir for 8 h, transfer to 15 vol% tetraethyl silicate in ethanol solution, soak at 60 °C for 48 h, replace with ethanol, and obtain composite silica by supercritical drying with ethanol;

[0040] The working conditions for supercritical drying are: pressure of 8 MPa and temperature of 275℃.

[0041] The preparation of self-healing polyurethane includes the following steps:

[0042] Under a nitrogen atmosphere, 15g of polypropylene carbonate diol, 2g of 4,4'-dithiodiphenylamine, 30mL of N,N-dimethylformamide, 3.5g of isophorone diisocyanate, and 0.2g of dibutyltin dilaurate were added and kept in a water bath at 80℃ for 3h. Then, a mixture of 2.7g of 4-hydroxyphenylboronic acid and 10mL of N,N-dimethylformamide was added and the mixture was stirred for another 2h to obtain a self-healing polyurethane.

[0043] S4: A backing coating is applied to one side of a polyester film base, and an imaging layer coating and a protective coating are applied to the other side in sequence. The film is then heat-set and wound up to obtain a high-temperature resistant, heat-sensitive medical film with stable imaging.

[0044] Example 2: A preparation process for a high-temperature resistant, heat-sensitive medical film with stable imaging, comprising the following steps:

[0045] S1: A back coating liquid is prepared using composite silica, slip agent, self-healing polyurethane, and epoxy silicone resin;

[0046] The composition of the back coating liquid by mass parts is: 3 parts composite silica, 2 parts slip agent, 13 parts self-healing polyurethane, and 24 parts epoxy silicone resin.

[0047] S2: An imaging layer coating solution was prepared using colorimetric microcapsules, dye microcapsules, and epoxy silicone resin;

[0048] The composition of the imaging layer coating solution by mass parts is: 19 parts of colorimetric microcapsules, 5 parts of dye microcapsules, and 34 parts of epoxy silicone resin.

[0049] S3: A protective coating is prepared using composite silica, self-healing polyurethane, and epoxy silicone resin.

[0050] The protective coating consists of the following components by weight: 2 parts composite silica, 13 parts self-healing polyurethane, and 23 parts epoxy silicone resin.

[0051] The preparation of composite silica includes the following steps:

[0052] (1) Under a nitrogen atmosphere, 2.88 g of 4-(4-hydroxyphenyl)-2,3-diazanaphthalene-1-one, 2.62 g of 4,4'-difluorobenzophenone, 1.93 g of potassium carbonate, 7.5 mL of dimethyl sulfoxide, and 15 mL of toluene were mixed, heated to 138 °C and kept at that temperature for 2.5 h, heated to 155 °C and kept at that temperature for 25 min, heated to 175 °C and kept at that temperature for 1 h, cooled to 20 °C and added a mixture of 0.78 g of 4-aminophenol, 0.7 g of potassium carbonate, 2.5 mL of dimethyl sulfoxide, and 5 mL of toluene, heated to 140 °C and kept at that temperature for 3 h, heated to 165 °C and kept at that temperature for 3 h, washed with water until neutral, filtered, washed successively with anhydrous ethanol and deionized water until the filtrate was neutral, dried, and the amino-naphthalene-biphenyl polyarylether ketone was obtained.

[0053] (2) Mix 0.5 mmol tetraethyl silicate, 2 mL deionized water and 6 mL ethanol, add 0.5 μL nitric acid and stir for 2 h, add 0.5 mmol aluminum chloride hexahydrate, 8 mL ethanol and 2 mL deionized water mixture and stir for 1.5 h, add 0.5 g amino-naphthyl biphenyl polyarylether ketone and stir for 8.5 h, transfer to 15 vol% tetraethyl silicate in ethanol solution, soak at 60 °C for 48 h, replace with ethanol, and obtain composite silica by supercritical drying with ethanol;

[0054] The working conditions for supercritical drying are: pressure of 8 MPa and temperature of 275℃.

[0055] The preparation of self-healing polyurethane includes the following steps:

[0056] Under a nitrogen atmosphere, 15g of polypropylene carbonate diol, 2g of 4,4'-dithiodiphenylamine, 30mL of N,N-dimethylformamide, 3.5g of isophorone diisocyanate, and 0.2g of dibutyltin dilaurate were added and kept in a water bath at 83℃ for 2.5h. Then, a mixture of 2.7g of 4-hydroxyphenylboronic acid and 10mL of N,N-dimethylformamide was added and the mixture was stirred for another 2.5h to obtain a self-healing polyurethane.

[0057] S4: A backing coating is applied to one side of a polyester film base, and an imaging layer coating and a protective coating are applied to the other side in sequence. The film is then heat-set and wound up to obtain a high-temperature resistant, heat-sensitive medical film with stable imaging.

[0058] Example 3: A preparation process for a high-temperature resistant, heat-sensitive medical film with stable imaging, comprising the following steps:

[0059] S1: A back coating liquid is prepared using composite silica, slip agent, self-healing polyurethane, and epoxy silicone resin;

[0060] The composition of the back coating liquid by mass parts is: 4 parts composite silica, 3 parts slip agent, 16 parts self-healing polyurethane, and 25 parts epoxy silicone resin.

[0061] S2: An imaging layer coating solution was prepared using colorimetric microcapsules, dye microcapsules, and epoxy silicone resin;

[0062] The composition of the imaging layer coating solution by mass parts is: 21 parts of colorimetric microcapsules, 7 parts of dye microcapsules, and 36 parts of epoxy silicone resin.

[0063] S3: A protective coating is prepared using composite silica, self-healing polyurethane, and epoxy silicone resin.

[0064] The protective coating consists of the following components by weight: 3 parts composite silica, 15 parts self-healing polyurethane, and 25 parts epoxy silicone resin.

[0065] The preparation of composite silica includes the following steps:

[0066] (1) Under a nitrogen atmosphere, 2.88 g of 4-(4-hydroxyphenyl)-2,3-diazanaphthalene-1-one, 2.62 g of 4,4'-difluorobenzophenone, 1.93 g of potassium carbonate, 7.5 mL of dimethyl sulfoxide, and 15 mL of toluene were mixed, heated to 140 °C and kept at that temperature for 2 h, then heated to 160 °C and kept at that temperature for 20 min, then heated to 175 °C and kept at that temperature for 1 h, then cooled to 25 °C and added a mixture of 0.78 g of 4-aminophenol, 0.7 g of potassium carbonate, 2.5 mL of dimethyl sulfoxide, and 5 mL of toluene, then heated to 140 °C and kept at that temperature for 3 h, then heated to 165 °C and kept at that temperature for 3 h, then washed with water until neutral, filtered, and washed successively with anhydrous ethanol and deionized water until the filtrate was neutral, then dried to obtain amino-naphthalene-biphenyl polyarylether ketone;

[0067] (2) Mix 0.5 mmol tetraethyl silicate, 2 mL deionized water and 6 mL ethanol, add 0.5 μL nitric acid and stir for 2 h, add 0.5 mmol aluminum chloride hexahydrate, 8 mL ethanol and 2 mL deionized water mixture and stir for 2 h, add 0.5 g amino-naphthyl biphenyl polyarylether ketone and stir for 9 h, transfer to 15 vol% tetraethyl silicate in ethanol solution, soak at 60 °C for 48 h, replace with ethanol, and dry with ethanol supercritical drying to obtain composite silica;

[0068] The working conditions for supercritical drying are: pressure of 8 MPa and temperature of 275℃.

[0069] The preparation of self-healing polyurethane includes the following steps:

[0070] Under a nitrogen atmosphere, 15g of polypropylene carbonate diol, 2g of 4,4'-dithiodiphenylamine, 30mL of N,N-dimethylformamide, 3.5g of isophorone diisocyanate, and 0.2g of dibutyltin dilaurate were added and kept in a water bath at 85℃ for 2h. Then, a mixture of 2.7g of 4-hydroxyphenylboronic acid and 10mL of N,N-dimethylformamide was added and the mixture was stirred for another 3h to obtain a self-healing polyurethane.

[0071] S4: A backing coating is applied to one side of a polyester film base, and an imaging layer coating and a protective coating are applied to the other side in sequence. The film is then heat-set and wound up to obtain a high-temperature resistant, heat-sensitive medical film with stable imaging.

[0072] Comparative Example 1: Using Example 3 as the control group, no aluminum chloride hexahydrate was added in the preparation of composite silica, and other processes were normal.

[0073] Comparative Example 2: Using Example 3 as the control group, no amino-modified naphthalene-biphenyl polyarylether ketone was added in the preparation of composite silica, and other processes were normal.

[0074] Comparative Example 3: Using Example 3 as the control group, the composite silica was replaced with silica (S433684: Aladdin reagent), and other processes were normal.

[0075] Comparative Example 4: Using Example 3 as the control group, no 4,4'-dithiodiphenylamine was added during the preparation of the self-healing polyurethane, and other processes were normal.

[0076] Comparative Example 5: Using Example 3 as the control group, no 4-hydroxyphenylboronic acid was added during the preparation of the self-healing polyurethane, and other processes were normal.

[0077] Comparative Example 6: Example 3 served as the control group, with no self-healing polyurethane added and other processes proceeding normally.

[0078] In the examples and comparative examples:

[0079] The preparation of the dye microcapsules includes the following steps:

[0080] 5g of melamine, 8.3g of 37% formaldehyde solution, and 50g of deionized water were mixed, and the pH was adjusted to 9.5. The mixture was then incubated in a water bath at 80℃ for 40 minutes to obtain a melamine resin prepolymer. 7.5g of thermosensitive dye TIH1000, 0.7g of Span 80, and 40g of deionized water were mixed and emulsified at 12000r / min for 25 minutes. The melamine resin prepolymer was then added, and the mixture was incubated in a water bath at 70℃ for 40 minutes. The pH was adjusted to 4, and the mixture was stirred at 400r / min for 8 hours. The mixture was then filtered and dried to obtain dye microcapsules.

[0081] The preparation of the chromogenic microcapsules includes the following steps:

[0082] Mix 5g melamine, 8.3g 37% formaldehyde solution, and 50g deionized water, adjust the pH to 9.5, and incubate at 80℃ for 40min to obtain melamine resin prepolymer. Mix 7.5g color developer TIA400, 0.7g Span 80, and 40g deionized water, emulsify at 12000r / min for 25min, add the melamine resin prepolymer, incubate at 70℃ for 40min, adjust the pH to 4, stir at 400r / min for 8h, filter, and dry to obtain colorimetric microcapsules.

[0083] In the examples and comparative examples: the thickness of the protective layer is 2 μm, the thickness of the imaging layer is 5 μm, the thickness of the polyester substrate is 200 μm, and the thickness of the back layer is 1 μm.

[0084] Sources of raw materials used in the examples and comparative examples:

[0085] Polyester sheet base: extruded from EVA (VL730: Lotte Chemical); Organosilicon slip agent HMB-6301: Dow Corning; Epoxy organosilicon resin SDH-023-7: Hubei Xinrunde Chemical Co., Ltd.; 4-(4-hydroxyphenyl)-2,3-diazanaphth-1-one (industrial grade), 4,4'-difluorobenzophenone (industrial grade): Dalian Baoli New Materials Co., Ltd.; 4-aminophenol 123-30-8: Wuhan Xinxin Jiali Biotechnology Co., Ltd.; Tetraethyl silicate T110596, aluminum chloride hexahydrate A112509, N,N-dimethylformamide, dibutyltin dilaurate D1 00274, Span 80S431923, Melamine M108433: Aladdin Reagent; Thermosensitive Dye TIH1000, Color Developer TIA400: Nippon Kayaku Co., Ltd.; 4,4'-Dithiodiphenylamine B11712: West Asia Chemical Technology (Shandong) Co., Ltd.; Isophorone Diisocyanate CHON: Wuhan Kanos Technology Co., Ltd.; 4-Hydroxyphenylboronic Acid S50047: Shanghai Yuanye Biotechnology Co., Ltd.; Polypropylene Carbonate Diol (Molecular Weight 2000): Guangdong Huahui New Materials; Potassium Carbonate, Dimethyl Sulfoxide, Toluene, Ethanol, Nitric Acid, Formaldehyde, Analytical Grade: Sinopharm Group Reagent.

[0086] Performance testing:

[0087] Tensile strength: The specimens were cut to a length of 30 mm and a width of 20 mm and tested on an electronic universal testing machine at a tensile speed of 100 mm / min; Antistatic properties: Characterized by surface resistivity, according to GB / T 1410-2006; Hydrophobicity: The water contact angle was measured using a 2 μL water droplet; Self-healing properties: A 1 μm deep and 100 μm long scratch was made on the surface of the protective layer, and the sample was kept at 70℃ for 2 h; The results are shown in the table below.

[0088] Tensile strength (MPa) Surface resistivity (Ω) Water contact angle (°) Self-repair rate (%) Example 1 14.2 <![CDATA[1.3×10 6 ]]> 151 100 Example 2 14.4 <![CDATA[1.1×10 6 ]]> 152 100 Example 3 14.8 <![CDATA[1×10 6 ]]> 155 100 Comparative Example 1 8.7 <![CDATA[8.9×10 6 ]]> 141 95 Comparative Example 2 9.3 <![CDATA[6.7×10 6 ]]> 143 99 Comparative Example 3 7.6 <![CDATA[1×10 7 ]]> 139 90 Comparative Example 4 11.5 <![CDATA[3.2×10 6 ]]> 149 85 Comparative Example 5 11.6 <![CDATA[3.3×10 6 ]]> 148 87 Comparative Example 6 10.2 <![CDATA[5.1×10 6 ]]> 146 63

[0089] This invention provides a high-temperature resistant thermosensitive medical film with stable imaging and its preparation process. The prepared film has high high-temperature resistance, water resistance, and antistatic properties, and provides stable imaging and clear color development when used as a medical film.

[0090] Comparing Example 3 with Comparative Examples 1 and 3, it can be seen that the silica introduced in this invention is in the form of aerogel. Compared with powdered silica, aerogel has the characteristics of high specific surface area, high porosity, and low density, but it also has the disadvantage of low mechanical strength at high temperatures. This invention introduces an alumina phase into the silica aerogel, which improves the high temperature resistance of the film and gives it better antistatic properties. During printing, the composite silica can achieve rapid heat dissipation, thereby improving the imaging stability and clarity of the film.

[0091] Comparing Example 3 with Comparative Example 2, it can be seen that modifying silica aerogel doped with alumina phase using aminated naphthalene-biphenyl polyetherketone (AMP) improves the uniformity of alumina-doped silica aerogel dispersion in the back layer, while also improving the hydrophobicity, high temperature resistance, and antistatic properties of the back layer. Furthermore, the AMP and self-healing polyurethane in the composite silica act as curing agents for epoxy silicone resin, introducing a rigid, twisted, non-coplanar naphthalene-biphenyl structure into the back layer and protective layer, resulting in a cured coating with good thermodynamic and heat resistance properties.

[0092] Comparing Example 3 with Comparative Examples 4, 5, and 6, it can be seen that introducing self-healing polyurethane into the backing and protective layers, using polypropylene carbonate diol as the soft segment, isophorone diisocyanate as the hard segment, and 4,4'-dithiodiphenylamine and 4-hydroxyphenylboronic acid as chain extenders to synthesize self-healing polyurethane, the abundant benzene ring structure and boron-oxygen six-membered ring structure endow it with a high crosslinking density, giving the coating good mechanical strength and a complex conductive network; the dynamic covalent boron-oxygen six-membered ring contained in the self-healing polyurethane, the disulfide bonds in the self-healing polyurethane, and the metal-disulfide dynamic combination and hydrogen bonds present in the metal in the composite silica, endow the film with self-healing properties at room temperature, thereby extending the service life of the film.

[0093] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the present invention's specification under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A preparation process for a high-temperature resistant, heat-sensitive medical film with stable imaging, characterized in that, Includes the following steps: S1: A back coating liquid is prepared using composite silica, slip agent, self-healing polyurethane, and epoxy silicone resin; S2: An imaging layer coating solution was prepared using colorimetric microcapsules, dye microcapsules, and epoxy silicone resin; S3: A protective coating is prepared using composite silica, self-healing polyurethane, and epoxy silicone resin. S4: A backing coating is applied to one side of a polyester film base, and an imaging layer coating and a protective coating are applied to the other side in sequence. The film is then heat-set and wound up to obtain a high-temperature resistant, heat-sensitive medical film with stable imaging. The preparation of composite silica includes the following steps: (1) Under a nitrogen atmosphere, 4-(4-hydroxyphenyl)-2,3-diazanaphthalene-1-one, 4,4'-difluorobenzophenone, potassium carbonate, dimethyl sulfoxide and toluene were mixed, heated to 135-140℃ and kept at 2-3h, heated to 150-160℃ and kept at 20-30min, heated to 175℃ and kept at 1h, cooled to 18-25℃ and added a mixture of 4-aminophenol, potassium carbonate, dimethyl sulfoxide and toluene, heated to 140℃ and kept at 3h, heated to 165℃ and kept at 3h, washed with water until neutral, filtered, washed successively with anhydrous ethanol and deionized water until the filtrate was neutral, dried to obtain amino-naphthalene-biphenyl polyarylether ketone; (2) Mix tetraethyl silicate, deionized water and ethanol, add nitric acid and stir for 2 hours, add aluminum chloride hexahydrate, ethanol and deionized water mixture and stir for 1-2 hours, add amino-naphthyl biphenyl polyarylether ketone and stir for 8-9 hours, transfer to ethanol solution of tetraethyl silicate, soak at 60°C for 48 hours, replace with ethanol, and obtain composite silica by supercritical drying with ethanol; The preparation of self-healing polyurethane includes the following steps: Under a nitrogen atmosphere, polypropylene carbonate diol, 4,4'-dithiodiphenylamine, and N,N-dimethylformamide were mixed, and isophorone diisocyanate and dibutyltin dilaurate were added. The mixture was kept in a water bath at 80-85°C for 2-3 hours. Then, a mixture of 4-hydroxyphenylboronic acid and N,N-dimethylformamide was added, and the mixture was stirred for another 2-3 hours to obtain self-healing polyurethane.

2. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, The slip agent is an organosilicon slip agent.

3. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, The composition of the backing coating liquid by mass parts is as follows: 2-4 parts of composite silica, 1-3 parts of slip agent, 12-16 parts of self-healing polyurethane, and 21-25 parts of epoxy silicone resin.

4. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, The imaging layer coating solution consists of the following components by mass: 17-21 parts of colorimetric microcapsules, 3-7 parts of dye microcapsules, and 33-36 parts of epoxy silicone resin.

5. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, The protective coating consists of the following components by weight: 1-3 parts composite silica, 10-15 parts self-healing polyurethane, and 20-25 parts epoxy silicone resin.

6. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, In the preparation of composite silica, the working conditions for supercritical drying are: pressure of 8 MPa and temperature of 275℃.

7. The preparation process of a high-temperature resistant, heat-sensitive medical film with imaging stability according to claim 1, characterized in that, In the preparation of self-healing polyurethane, the mass ratio of polypropylene carbonate diol, 4,4'-dithiodiphenylamine, and 4-hydroxyphenylboronic acid is 15:2:2.

7.

8. A high-temperature resistant, thermosensitive medical film with stable imaging, characterized in that, Prepared according to any one of the preparation processes described in claims 1-7.