CN112882335B - Silver-containing thermosensitive imaging layer, thermosensitive printing medical film and preparation method thereof - Google Patents

Abstract

The invention discloses a silver-containing thermal imaging layer, a thermal printing medical film and a preparation method thereof, wherein the silver-containing thermal imaging layer comprises the following components: the toner comprises organic silver, a binder, a reducing agent, a stabilizer, a toner and a cross-linking agent, wherein the addition amount of the reducing agent is 0.45-1 g, the addition amount of the stabilizer is 0.18-0.4 g and the addition amount of the toner is 0.08-0.3 g based on 1g of the organic silver. Therefore, the film with the performance equivalent to that of the existing high-silver-content coated product can be prepared on the basis of using low-silver-content coating (calculated by silver, the coating amount is 0.5g/m ²～0.8g/m²), so that the use requirement is met, and the cost of the film is greatly reduced.

Description

Silver-containing thermal imaging layer, thermal printing medical film and preparation method thereof

Technical Field

The invention belongs to the technical field of imaging materials, and in particular relates to a silver-containing thermal imaging layer, a thermal printing medical film and a preparation method thereof.

Background technique

Thermosensitive imaging materials based on long-chain silver carboxylates are the main medical image output hard copy materials in the field of medical imaging today, and are important carriers of medical images. There are currently two technical routes for this imaging material: photothermal imaging and direct thermal imaging. Both technologies have been widely used in the field of medical imaging. The imaging principles of these two technologies are the thermal reduction of organic silver. The difference is that in photothermal imaging technology, organic silver is thermally reduced under the catalytic action of silver halide photosensitive centers, and the factor affecting image contrast is the difference in the photosensitivity of silver halide under different light intensities, while in direct thermal imaging technology, organic silver is reduced at different temperatures, and the factor affecting image contrast is the temperature difference.

The most important factor affecting the overall quality of direct thermal imaging silver halide film is the performance of the film, and the most important performance is the maximum density (Dmax). When the maximum density is within a certain range, the overall quality of the film can be guaranteed to be at a better level, thereby improving the accuracy of doctors' diagnosis of the disease.

The current direct thermal imaging silver halide film products on the market are only owned by Agfa. In actual application, it is found that when the maximum density is ≥3.1, the film meets the diagnostic requirements, has the best application effect, and has excellent overall quality. In order to ensure that the maximum density meets the standard, the coating amount of the existing products is about 1.0g/㎡, and due to the high price of metallic silver, the cost of the film remains high.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one object of the present invention is to provide a silver-containing thermal imaging layer, a thermal printing medical film and a preparation method thereof, wherein the silver-containing thermal imaging layer can be used to prepare a film having performance equivalent to that of existing high-silver-content coated products on the basis of using a low coating amount of silver (the coating amount is 0.5 g/m ² to 0.8 g/m ² in terms of silver), thereby meeting the use requirements and thus greatly reducing the cost of the film.

In one aspect of the present invention, the present invention provides a silver-containing thermal imaging layer. According to an embodiment of the present invention, the silver-containing thermal imaging layer comprises: organic silver, a binder, a reducing agent, a stabilizer, a toner and a cross-linking agent,

Wherein, based on 1g of the organic silver, the added amount of the reducing agent is 0.45g to 1g, the added amount of the stabilizer is 0.18g to 0.4g, and the added amount of the toner is 0.08g to 0.3g.

According to the silver-containing thermal imaging layer of the embodiment of the present invention, by adjusting the amount of reducing agent, stabilizer and toner to match the amount of organic silver, the imaging layer can be prepared on the basis of using a low coating silver amount (the coating amount is 0.5g/ ^m2 to 0.8g/ ^m2 in terms of silver) to obtain a film with performance equivalent to that of existing high-silver coating products, thereby meeting the use requirements and greatly reducing the cost of the film.

In addition, the silver-containing thermal imaging layer according to the above embodiment of the present invention may also have the following additional technical features:

In some embodiments of the present invention, the organic silver is a long-chain organic silver, preferably at least one of silver eicosanoate, silver docosanoate and silver tetracosanoate.

In some embodiments of the present invention, the reducing agent is a phenolic reducing agent, preferably at least one of a phenolic reducing agent and a naphthol reducing agent, more preferably a polyhydroxyphenol reducing agent, and most preferably at least one of 3,4-dihydroxybenzonitrile and 3,4-dihydroxybenzophenone.

In some embodiments of the present invention, the reducing agent is a combination of 3,4-dihydroxybenzonitrile and 3,4-dihydroxybenzophenone, wherein, based on 1g of the organic silver, the amount of 3,4-dihydroxybenzonitrile added is 0.4g to 0.8g, and the amount of 3,4-dihydroxybenzophenone added is 0.05g to 0.2g. Thus, the sample can be prevented from yellowing when exposed to light while ensuring that the sample density meets the use requirements.

In some embodiments of the present invention, the stabilizer includes at least one of tetrachlorophthalic acid and azelaic acid.

In some embodiments of the present invention, the stabilizer is a combination of tetrachlorophthalic acid and azelaic acid, wherein, based on 1g of the organic silver, the amount of tetrachlorophthalic acid added is 0.08g to 0.2g, and the amount of azelaic acid added is 0.1g to 0.2g. Thus, the film stability can be ensured while avoiding the reduction of the film density.

In some embodiments of the present invention, the toner includes at least one of casalan and acesulfame potassium.

In some embodiments of the present invention, the toner is a combination of casalan and acesulfame potassium, wherein, based on 1g of the organic silver, the amount of casalan added is 0.05g to 0.2g, and the amount of acesulfame potassium added is 0.03g to 0.1g. Thus, the film can be prevented from having a reddish or yellowish hue and increasing the fatigue of watching the film.

In some embodiments of the present invention, based on 1 g of the organic silver, the added amount of the binder is 2 g to 4 g, and the added amount of the cross-linking agent is 0.4 g to 0.7 g.

In some embodiments of the present invention, the adhesive includes at least one of PVB and epoxy resin.

In some embodiments of the present invention, the cross-linking agent includes at least one of MDI and IPDI.

In the second aspect of the present invention, the present invention proposes a method for preparing a thermal printing medical film. According to an embodiment of the present invention, the method comprises: applying a thermal imaging layer on a base film and then drying it to obtain a thermal printing medical film, wherein the thermal imaging layer is the above-mentioned silver-containing thermal imaging layer. Thus, by using the above-mentioned silver-containing thermal imaging layer, a film having performance equivalent to that of existing high-silver-content coated products can be prepared on the basis of using a low coating silver amount (in terms of silver, the coating amount is 0.5g/ ^m2 to 0.8g/ ^m2 ), meeting the use requirements, thereby greatly reducing the cost of the film.

In some embodiments of the present invention, the silver-containing thermal imaging layer is applied in an amount of 0.5 to 0.8 g in terms of silver based on 1 m ² of the base film.

In the third aspect of the present invention, a thermal printing medical film is provided. According to an embodiment of the present invention, the thermal printing medical film is prepared by the above method. Therefore, the film has the same performance as the existing high silver coating products on the basis of using a low silver coating amount (the coating amount is 0.5g/ ^m2 to 0.8g/ ^m2 in terms of silver), meets the use requirements, and thus greatly reduces the cost of the film.

Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below, which are intended to explain the present invention but are not to be construed as limiting the present invention.

In one aspect of the present invention, the present invention provides a silver-containing thermal imaging layer. According to an embodiment of the present invention, the silver-containing thermal imaging layer comprises: organic silver, a binder, a reducing agent, a stabilizer, a toner and a cross-linking agent, wherein, based on 1g of the organic silver, the adding amount of the reducing agent is 0.45g to 1g, the adding amount of the stabilizer is 0.18g to 0.4g, and the adding amount of the toner is 0.08g to 0.3g.

The inventors found that the development process of the thermal printing medical film of the present invention is that the stabilizer first forms a complex with organic silver, and the reducing agent "attacks" the complex under the support of the toner to "rob" the organic silver, and then an oxidation-reduction reaction occurs to produce silver atoms, and the silver atoms are accumulated into silver atom clusters. The final density of the film has a great relationship with the accumulation state and average particle size of the silver atom clusters. Therefore, in this process, the type and amount of the reducing agent, stabilizer, and toner have different degrees of influence on the final accumulation state of the silver atom clusters, and there is a certain degree of dynamic balance between the three, and this dynamic balance is not unique. Therefore, by adjusting the amount of reducing agent, stabilizer and toner to match the amount of organic silver, a new dynamic balance is established, and the imaging layer can be prepared on the basis of using a low coating silver amount (in terms of silver, the coating amount is 0.5g/ ^m2 ~0.8g/ ^m2 ) to obtain a film with performance equivalent to the existing high silver coating product, which meets the use requirements and thus greatly reduces the cost of the film.

Furthermore, the organic silver in the imaging layer is a long-chain organic silver, preferably at least one of silver eicosanoate, silver behenate and silver tetracosanoate, more preferably silver behenate. It should be noted that silver behenate can be prepared by commercially available methods or methods in the prior art, for example, it can be prepared by referring to the method in patent CN1006292168.

Further, the reducing agent in the imaging layer is a phenolic reducing agent, preferably at least one of a phenolic reducing agent and a naphthol reducing agent, more preferably a polyhydroxyphenolic reducing agent, and most preferably at least one of 3,4-dihydroxybenzonitrile and 3,4-dihydroxybenzophenone. According to a specific embodiment of the present invention, the reducing agent is a combination of 3,4-dihydroxybenzonitrile and 3,4-dihydroxybenzophenone, and based on 1g of the organic silver, the addition amount of the 3,4-dihydroxybenzonitrile is 0.4g to 0.8g, and the addition amount of the 3,4-dihydroxybenzophenone is 0.05g to 0.2g. The inventors have found that the ideal reduction effect cannot be achieved by using any one of the reducing agents alone. In the combined reducing agent of the present application, 3,4-dihydroxybenzonitrile is the main reducing agent and 3,4-dihydroxybenzophenone is the auxiliary reducing agent. The auxiliary reducing agent assists the main reducing agent in completing the reduction reaction, which can further improve the film density. If the addition amount of any one of the reducing agents is too low, it cannot meet the film's demand for high density, and if the addition amount is too high, it will cause unnecessary waste. Therefore, the combined reducing agent composed of the present application can avoid waste on the basis of meeting the film's demand for high density.

Furthermore, the stabilizer in the imaging layer includes at least one of tetrachlorophthalic acid and azelaic acid; preferably, it is a combination of tetrachlorophthalic acid and azelaic acid, wherein, based on 1g of the organic silver, the amount of the tetrachlorophthalic acid added is 0.08g to 0.2g, and the amount of the azelaic acid added is 0.1g to 0.2g. The inventors found that the two stabilizers have different complexation rates with silver ions, and the ideal complexation state cannot be achieved by using only one of the stabilizers. By adjusting the dosage of the two, different complexation states can be obtained, thereby achieving the purpose of screening the complexation state required for this product. If the dosage of any one of the stabilizers is too high or too low, the complexation state of the stabilizer and the organic silver that meets the application requirements cannot be obtained. Therefore, the combined stabilizer of the composition of the present application can achieve the complexation state required for this product.

Furthermore, the toner in the imaging layer is selected from organic substances that have strong complexing ability with silver ions, preferably including at least one of casalan and acesulfame potassium; more preferably, it is a combination of casalan and acesulfame potassium, wherein, based on 1g of the organic silver, the amount of casalan added is 0.05g to 0.2g, and the amount of acesulfame potassium added is 0.03g to 0.1g. The inventors have found that due to the difference in steric hindrance, the migration rates of casalan and acesulfame potassium in the adhesive are greatly different after combining with the reducing agent. By adjusting the amount and combination thereof, the migration rate that meets the film imaging requirements can be obtained, thereby ensuring that the film's high density and other properties such as the color tone of the sample are within the required range.

Furthermore, in the imaging layer, based on 1g of the organic silver, the amount of the binder added is 2g to 4g, and the amount of the crosslinker added is 0.4g to 0.7g. The inventors found that the binder provides a reaction site, and its amount directly affects the migration of the reducing agent, stabilizer, and toner during the development process, and the crosslinker adjusts the final state of the binder, and its amount directly affects the migration rate of the reducing agent, stabilizer, and toner during the development process. If the amount of adhesive is too low and the migration distance is too short, although the high density meets the use requirements, other application properties such as color tone will be significantly deteriorated and cannot meet the use requirements of the film. If the amount of adhesive is too high, the migration distance will be too long, which will affect the redox reaction and the final stacking state of the silver atom clusters, resulting in a high density that cannot meet the use requirements; at the same time, if the amount of cross-linking agent is too low, the coating is not dense enough, and the migration rate of the reducing agent, stabilizer, and toner in the adhesive is too fast. Although the high density can meet the requirements, other application properties such as color tone will be significantly deteriorated and cannot meet the use requirements of the film. If the amount of cross-linking agent is too high, the coating is too dense, and the migration rate of the reducing agent, stabilizer, and toner in the adhesive is too slow, which will affect the redox reaction and the final stacking state of the silver atom clusters, resulting in a high density that cannot meet the use requirements. And the adhesive includes at least one of PVB and epoxy resin; the cross-linking agent includes at least one of MDI and IPDI.

In the second aspect of the present invention, the present invention proposes a method for preparing a thermal printing medical film. According to an embodiment of the present invention, the method comprises: applying a thermal imaging layer on a base film and then drying it to obtain a thermal printing medical film, wherein the thermal imaging layer is the above-mentioned silver-containing thermal imaging layer. Thus, by using the above-mentioned silver-containing thermal imaging layer, a film with performance equivalent to that of existing high-silver-content coated products can be prepared on the basis of using a low coating silver amount (in terms of silver, the coating amount is 0.5g/ ^m2 to 0.8g/ ^m2 ), meeting the use requirements, thereby greatly reducing the cost of the film. Preferably, the base film is a PET film base or a photographic paper base, and based on ^1m2 of the base film, the application amount of the silver-containing thermal imaging layer is 0.5 to 0.8g in terms of silver. Thus, the cost of the film can be reduced while ensuring the quality of the film. It should be noted that the features and advantages described above for the silver-containing thermal imaging layer are also applicable to the method for preparing the thermal printing medical film, and will not be repeated here.

In the third aspect of the present invention, the present invention proposes a thermal printing medical film. According to an embodiment of the present invention, the thermal printing medical film is prepared by the above method. As a result, the film has the same performance as the existing high silver coating products on the basis of using a low coating silver amount (in terms of silver, the coating amount is 0.5g/ ^m2 to 0.8g/ ^m2 ), meets the use requirements, and thus greatly reduces the cost of the film. It should be noted that the features and advantages described above for the method for preparing thermal printing medical film are also applicable to the thermal printing medical film, and will not be repeated here.

The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. In addition, if not explicitly stated, all reagents used in the following embodiments are commercially available, or can be synthesized according to this article or known methods, and the reaction conditions not listed are also easily available to those skilled in the art.

Example 1

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in 10 g of PVB solution with a solid content of 20 wt% to obtain 11 g of dispersion A, and dispersion A, 0.6 g of 3,4-dihydroxybenzonitrile, 0.1 g of 3,4-dihydroxybenzophenone, 0.1 g of casalan, 0.05 g of acesulfame potassium, 0.1 g of tetrachlorophthalic acid, 0.15 g of azelaic acid, and 0.4 g of a crosslinking agent MDI were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating silver amount of 0.6 g/㎡.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

Example 2

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in 15 g of PVB solution with a solid content of 20 wt % to obtain 16 g of dispersion A, and dispersion A, 0.4 g of 3,4-dihydroxybenzonitrile, 0.05 g of 3,4-dihydroxybenzophenone, 0.05 g of casalan, 0.03 g of acesulfame potassium, 0.08 g of tetrachlorophthalic acid, 0.1 g of azelaic acid, and 0.5 g of crosslinking agent MDI were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating amount of silver of 0.5 g/㎡.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

Example 3

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in 20 g of PVB solution with a solid content of 20 wt % to obtain 21 g of dispersion A, and dispersion A, 0.8 g of 3,4-dihydroxybenzonitrile, 0.2 g of 3,4-dihydroxybenzophenone, 0.2 g of casalan, 0.1 g of acesulfame potassium, 0.2 g of tetrachlorophthalic acid, 0.2 g of azelaic acid, and 0.6 g of crosslinking agent MDI were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating silver amount of 0.8 g/㎡.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

Example 4

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in 17 g of PVB solution with a solid content of 20 wt% to obtain 18 g of dispersion A, and dispersion A, 0.4 g of 3,4-dihydroxybenzonitrile, 0.05 g of 3,4-dihydroxybenzophenone, 0.2 g of casalan, 0.1 g of acesulfame potassium, 0.08 g of tetrachlorophthalic acid, 0.1 g of azelaic acid, and 0.8 g of crosslinking agent MDI were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating silver amount of 0.7 g/㎡.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

Example 5

The organic silver is silver eicosanoate, the adhesive is epoxy resin, the cross-linking agent is IPDI, and the rest is the same as in Example 1.

Example 6

The organic silver is silver tetradecanoate, the adhesive is epoxy resin, the cross-linking agent is IPDI, and the rest is the same as in Example 1.

Comparative Example 1

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in PVB solution to obtain 12 g of dispersion A, and dispersion A, 0.6 g of 3,4-dihydroxybenzonitrile, 0.1 g of 3,4-dihydroxybenzophenone, 0.1 g of casalan, 0.05 g of acesulfame potassium, 0.1 g of tetrachlorophthalic acid, 0.15 g of azelaic acid, and 0.5 g of a cross-linking agent were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating amount of silver of 1.0 g/㎡.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

Comparative Example 2

Preparation of imaging layer coating liquid: 1 g of silver behenate powder was dispersed in PVB solution to obtain 12 g of dispersion A, and dispersion A, 0.6 g of 3,4-dihydroxybenzonitrile, 0.1 g of 3,4-dihydroxybenzophenone, 0.1 g of casalan, 0.05 g of acesulfame potassium, 0.1 g of tetrachlorophthalic acid, 0.15 g of azelaic acid, and 0.6 g of a cross-linking agent were mixed under stirring to obtain imaging layer coating liquid B;

Imaging layer coating: coating the imaging layer coating liquid B onto the PET film base and drying naturally to obtain the imaging layer sample C, with a coating amount of 0.45 g/㎡ of silver.

Protective layer coating: PVA, silicone oil dispersion, zinc stearate dispersion, polysilicic acid and boric acid are mixed to obtain a protective layer coating solution, and the protective layer coating solution is coated on the imaging layer sample C to obtain film D.

evaluate:

1. Evaluate the high density of film D obtained in Examples 1-6 and Comparative Examples 1-2:

2. High density test method:

(1) Test conditions

The samples must be equilibrated at a temperature of 25°C ± 5°C and a relative humidity of 50% ± 10% for at least 30 minutes before processing.

(2) Sampling

After the sample reaches equilibrium, take a sample and take any film from the unopened package as a test piece.

(3) Test piece printing

Use Fuji DryPix3000 camera to print photo paper to form 24 levels of density grayscale. After reading the 24 levels of density grayscale on the densitometer, a 24-level grayscale characteristic curve is formed.

(4) Density measurement

The density should be the national standard visual diffuse reflection density. The geometric conditions for density measurement should comply with the provisions of GB/T11500. The spectral conditions for density measurement should comply with the provisions of GB/T11501. The maximum density value corresponds to the maximum density Dmax on the 24-level grayscale characteristic curve.

The high density test results of the films obtained in Examples 1-6 and Comparative Examples 1-2 are shown in Table 1.

Table 1

As can be seen from the data in Table 1, the thermal imaging silver salt digital medical film prepared with low silver content in Examples 1-6 has comparable performance to the direct thermal imaging silver salt digital medical film of the existing coated silver content comparative example 1 and Agfa's existing products, meeting the use requirements. On this basis, if the coated silver content is further reduced, the contrast and high density will be lost to varying degrees, resulting in a serious decline in film quality and failure to meet diagnostic requirements. Therefore, the present application greatly reduces the coated silver content of the film while ensuring performance, thereby greatly reducing production costs.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims (3)

1. A silver-containing thermal imaging layer, characterized in that it comprises: organic silver, a binder, a reducing agent, a stabilizer, a toner and a cross-linking agent, Wherein, based on 1g of the organic silver, the amount of the reducing agent added is 0.45g~1g, the amount of the stabilizer added is 0.18g~0.4g, the amount of the toner added is 0.08g~0.3g, the amount of the binder added is 2g~4g, and the amount of the cross-linking agent added is 0.4g~0.7g; Based on 1 m ² of the base film, the application amount of the silver-containing thermal imaging layer is 0.5 to 0.8 g in terms of silver; The organic silver is at least one of silver eicosanoate, silver docosanoate and silver tetracosanoate; The reducing agent is a combination of 3,4-dihydroxybenzonitrile and 3,4-dihydroxybenzophenone, wherein, based on 1g of the organic silver, the added amount of the 3,4-dihydroxybenzonitrile is 0.4g-0.8g, and the added amount of the 3,4-dihydroxybenzophenone is 0.05g-0.2g; The stabilizer is a combination of tetrachlorophthalic acid and azelaic acid, wherein, based on 1g of the organic silver, the amount of the tetrachlorophthalic acid added is 0.08g-0.2g, and the amount of the azelaic acid added is 0.1g-0.2g; The toner is a combination of casalan and acesulfame potassium, wherein, based on 1g of the organic silver, the amount of casalan added is 0.05g-0.2g, and the amount of acesulfame potassium added is 0.03g-0.1g; The adhesive comprises at least one of PVB and epoxy resin; The cross-linking agent includes at least one of MDI and IPDI. 2. A method for preparing a thermal printing medical film, characterized in that it comprises: applying a thermal imaging layer on a base film and then drying it to obtain a thermal printing medical film, Wherein, the thermal imaging layer is the silver-containing thermal imaging layer as claimed in claim 1. 3. A thermal printing medical film, characterized in that the thermal printing medical film is prepared by the method described in claim 2.