Medicinal aluminum foil surface coating iodine-resistant coating, preparation method thereof and medicinal aluminum foil

Abstract

The invention relates to the technical field of medicinal aluminum foil packaging, and particularly discloses an iodine-resistant coating for coating the surface of a medicinal aluminum foil, a preparation method of the iodine-resistant coating and the medicinal aluminum foil. The invention relates to an iodine-resistant coating for coating the surface of a medicinal aluminum foil. The iodine-resistant coating is prepared from the following raw materials in parts by weight: 25-30 parts of acrylic resin; 25 to 65 parts of water; 1 to 10 parts of ethanol; 1 to 10 parts of isopropanol; 1-3 parts of water-soluble phenolic resin; 2-5 parts of water glass; the preparation method comprises the following steps: mixing the acrylic resin, the ethanol and the isopropanol to obtain a material A; mixing water, water glass and water-soluble phenolic resin to obtain a material B; and mixing the material A and the material B, stirring, dispersing and grinding. After the iodine-resistant coating coated on the surface of the medicinal aluminum foil is applied, a coating formed by the coating is not prone to large softening, deformation and other phenomena under the influence of severe temperature changes, and then the coating shows good stability and can play an excellent and stable iodine-resistant effect in the application process.

Description

Technical Field

[0001] The present application relates to the technical field of pharmaceutical aluminum foil packaging, and more specifically, to a pharmaceutical aluminum foil surface coated with an iodine-blocking coating and a preparation method thereof, and a pharmaceutical aluminum foil. Background Art

[0002] Medicinal aluminum foil is a kind of aluminum foil material specially used for packaging medicines. It is widely used in medicine packaging. It can effectively protect the ingredients of medicines and the external environment that is easily contaminated, ensure the quality of medicines, and extend the shelf life of medicines.

[0003] Medicinal aluminum foil is a composite material made of multiple layers of different materials, generally composed of substrate, adhesive, ink and coating. Among them, the substrate is the main material of medicinal aluminum foil, mostly pure aluminum or aluminum alloy, which mainly plays a protective role; the adhesive is used to bond the layers of materials; the ink is used to print brand name, manufacturer and other information; the coating is used to increase corrosion resistance, enhance material toughness, etc. When the medicine contains iodine, due to the high volatility of iodine, the iodine content decreases with the increase in storage, affecting the efficacy of the medicine. Therefore, it is necessary to spray a coating with good iodine blocking effect on the surface of the composite aluminum foil. Acrylic materials usually have a higher molecular weight and a compact molecular structure, which enables them to effectively block the diffusion of volatile organic compounds and form a dense film to prevent small molecular organic matter from passing through. Therefore, the coating is mostly formed by coating with acrylic resin coatings.

[0004] With respect to the above-mentioned related technologies, the inventors believe that the coating formed by acrylic resin will soften and deform under drastic temperature changes. At this time, the performance stability is poor, and it is difficult to exert a relatively stable iodine-blocking effect. Therefore, it is urgent to propose a solution to solve the above-mentioned technical problems. Summary of the invention

[0005] In order to enable the iodine-barrier coating on the surface of the composite aluminum foil to exert a relatively excellent and stable iodine-barrier effect under drastic temperature changes, the present application provides an iodine-barrier coating coated on the surface of a medicinal aluminum foil and a preparation method thereof, and a medicinal aluminum foil.

[0006] In the first aspect, the present application provides an iodine-blocking coating on the surface of a medicinal aluminum foil, which adopts the following technical solution: an iodine-blocking coating on the surface of a medicinal aluminum foil, which is made of raw materials containing the following parts by weight: Acrylic resin 25-30 parts; 25-65 parts water; 1-10 parts of ethanol; 1-10 parts of isopropyl alcohol; 1-3 parts of water-soluble phenolic resin; 2-5 parts of water glass.

[0007] By adopting the above technical solution, acrylic resin is easy to soften at high temperature, while phenolic resin has high heat resistance. After mixing acrylic resin and phenolic resin, the temperature resistance of the coating film can be improved to a certain extent. After mixing water glass with acrylic resin, it can not only enhance the adhesion between the coating and the substrate, but also allow the acrylic resin to fill the gaps in the -Si-O-Si-net structure formed by water glass, thereby delaying the expansion and contraction of the coating film under cold and hot changes, bringing about an improvement in excellent structural stability. At the same time, water-soluble phenolic resin and water glass can also play an excellent compounding and synergistic role in the mixed system of iodine-resistant coating on the surface of medicinal aluminum foil; first, under the action of temperature, the -OH between the molecular chains of water-soluble phenolic resin undergoes dehydration condensation reaction to form a cross-linked network of the resin body; secondly, water glass can also form silicate gel under the action of water-soluble phenolic resin; and an interpenetrating network gel system can be formed between the above-mentioned resin body cross-linked network and silicate gel, and the interpenetrating network structure of this gel system is relatively dense. When affected by drastic temperature changes, it can maintain its own excellent structural stability, and make the coating formed by coating the surface of medicinal aluminum foil with iodine-resistant coating not prone to large softening, deformation and the like, thereby showing better stability and being able to exert a relatively excellent and stable iodine-resistant effect during application.

[0008] Preferably, the weight ratio of the water-soluble phenolic resin to water glass is 2:3.

[0009] By adopting the above technical scheme, the water-soluble phenolic resin and water glass in the above weight ratio can have a better compounding effect when mixed and used, and the gel system formed by the combination of the two can be more evenly distributed, and the interpenetrating network structure of the gel system has a strong ability to protect the acrylic resin under drastic temperature changes, so that the iodine-blocking coating on the surface of the obtained medicinal aluminum foil can exert a relatively excellent and stable iodine-blocking effect under drastic temperature changes after application.

[0010] Preferably, the average molecular weight of the acrylic resin is 6000-8000.

[0011] By adopting the above technical scheme, the larger the molecular weight of the acrylic resin, the better its stability under the influence of temperature changes, the stronger the polymerization force within the molecule, and the better able to resist the damage to the material caused by temperature changes; however, the molecular weight of the acrylic resin will also affect the interpenetration and bonding of the gel system formed by the acrylic resin, water glass and water-soluble phenolic resin, and the above average molecular weight of 6000-8000 can enable the cooperation between water glass and water-soluble phenolic resin to exert a relatively excellent and stable corresponding effect in the acrylic resin system, thereby enabling the coating formed by coating the iodine-resistant coating on the surface of the medicinal aluminum foil to exhibit strong application stability under drastic temperature changes.

[0012] Preferably, 4-6 parts by weight of a functional additive are also added to the raw material, wherein the functional additive is composed of nanocellulose fibers and porous diatomaceous earth, and the weight ratio of the nanocellulose fibers to the porous diatomaceous earth is (3-7):1.

[0013] By adopting the above technical scheme, the addition of nanocellulose fibers can increase the drying speed of water-based coatings, reduce the shrinkage of coatings, improve the smoothness and glossiness of coatings, and form a gel-like structure, thereby improving the structural stability; porous diatomaceous earth has the characteristics of being fine and porous, which can not only effectively thicken and increase the viscosity and concentration of the paint film, but also improve the stability of the coating film under temperature changes; at the same time, when nanocellulose fibers and porous diatomaceous earth are used as functional additives, they can play an excellent compounding and synergistic role with each other. Through the large number of microscopic pores on the surface of porous diatomaceous earth and its own adsorption characteristics, they can form a network structure with porous diatomaceous earth as the connection point in the coating system with nanocellulose fibers, and the gel system formed by the combination with water glass and water-soluble phenolic resin shows better complementarity and binding, which can significantly enhance the stability of the iodine-blocking coating coated on the surface of medicinal aluminum foil under drastic temperature changes, so that the iodine-blocking effect brought by the coating can be more stably and effectively exerted.

[0014] Preferably, the weight ratio of the nanocellulose fibers to the porous diatomaceous earth is 5:1.

[0015] By adopting the above technical scheme, when the nanocellulose fibers and porous diatomaceous earth in the above weight ratio are mixed and used, the compounding effect between them is better, the network structure formed by the combination of the two can be more evenly distributed, and the gel system formed by the combination with water glass and water-soluble phenolic resin can also form a more sufficient combination, so that the corresponding effect brought by the functional additives is better, and finally the iodine-resistant coating coated on the surface of the medicinal aluminum foil has excellent application stability under drastic temperature changes.

[0016] Preferably, the diameter of the nanocellulose fiber is 10-100 nm and the length is 20-50 microns; the average pore size of the porous diatomaceous earth is 500-1000 nm and the particle size is 4-10 microns.

[0017] By adopting the above technical scheme, when the nanocellulose fibers and porous diatomaceous earth of the above specifications are combined, not only the mutual bonding performance is relatively stable, but also the formed network structure is relatively dense, and the adaptability with the gel system formed by combining with water glass and water-soluble phenolic resin is better, thereby making the corresponding improvement effect brought about by the application of functional additives better.

[0018] Preferably, 0.5-1 parts by weight of polyacrylamide is also added to the raw materials.

[0019] By adopting the above technical solution, polyacrylamide is used as a suspending agent in the coating, which can significantly improve the suspension and adhesion effects of the coating, thereby enhancing the temperature change resistance of the coating film; at the same time, the first use of polyacrylamide can also enhance the gel system formed by the combination of water glass and water-soluble phenolic resin, and bring about a significant improvement in thermal stability, so that the application stability of the iodine-resistant coating coated on the surface of the medicinal aluminum foil under drastic temperature changes can be significantly improved.

[0020] In the second aspect, the present application provides a method for preparing a medicinal aluminum foil surface coated with an iodine-blocking coating, using the following technical solution: A method for preparing a medicinal aluminum foil surface coated with an iodine-blocking coating comprises the following steps: (1) preparing raw materials including acrylic resin, water, ethanol, isopropanol, water-soluble phenolic resin and water glass according to a proportion; (2) mixing the acrylic resin, ethanol and isopropanol in step (1) to obtain material A; mixing the water, water glass and water-soluble phenolic resin in step (1) to obtain material B; (3) After mixing material A and material B in step (2), stirring, dispersing and grinding are performed to obtain an iodine-blocking coating for coating the surface of the medicinal aluminum foil.

[0021] By adopting the above technical scheme, the above preparation method is simple to operate, and the raw materials are mixed in steps during the process, which is conducive to quality control during the process, and can make the various component raw materials fully mixed and combined, so that the iodine-resistant coating on the surface of the obtained medicinal aluminum foil has excellent and stable application quality, and is also suitable for large-scale industrial production as a whole.

[0022] In a third aspect, the present application provides a medicinal aluminum foil, which adopts the following technical solution: A medicinal aluminum foil comprises a composite aluminum foil and an iodine-blocking coating on the surface of the composite aluminum foil. The iodine-blocking coating is obtained by coating the surface of any of the above medicinal aluminum foils with the iodine-blocking coating and drying the coating.

[0023] By adopting the above technical solution, when the medicine contains iodine, due to the high volatility of iodine, the iodine content decreases as the storage time increases, affecting the efficacy of the medicine. The coating formed by applying the iodine-blocking coating on the surface of the above-mentioned medicinal aluminum foil can exert an excellent and stable iodine-blocking effect during the application process.

[0024] Preferably, the composite aluminum foil is obtained by bonding a nylon layer, an aluminum foil layer and a PVC layer with an adhesive.

[0025] By adopting the above technical solution, the nylon layer is located at the outermost layer, which plays a protective role and prevents the external environment from damaging the internal materials; the aluminum foil layer usually adopts pure aluminum or aluminum alloy, which has good barrier properties and can effectively isolate the contact between the medicine and the external environment, and prevent the medicine from being affected by moisture, oxidation, etc.; the PVC layer has good wear resistance, tear resistance, compression resistance and impact resistance, and can effectively protect the medicine from the influence of the external environment; and the composite aluminum foil of the above structure has strong applicability as a whole.

[0026] In summary, this application has the following beneficial effects: 1. The present application uses water-soluble phenolic resin and water glass in coating the iodine-blocking coating on the surface of the medicinal aluminum foil, and through the excellent compounding and synergistic effect brought by the combination of the two, the coating formed by the application can maintain its excellent structural stability when subjected to drastic temperature changes, and exert a relatively excellent and stable iodine-blocking effect; 2. The present application, by adding functional additives composed of nanocellulose fibers and porous diatomaceous earth, can form a network structure with porous diatomaceous earth as a connection point in the coating system, and the gel system formed by the combination of water glass and water-soluble phenolic resin shows better complementarity and combination, and the application stability of the iodine-blocking coating on the surface of the medicinal aluminum foil under drastic temperature changes is significantly improved; 3. The present application also uses polyacrylamide to enhance the gel system formed by the combination of water glass and water-soluble phenolic resin, and brings about a significant improvement in thermal stability, thereby significantly enhancing the stability of the iodine-blocking coating coated on the surface of the medicinal aluminum foil under drastic temperature changes, so that the iodine-blocking effect brought by the coating can be more stably and effectively exerted. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to examples and comparative examples.

[0028] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present application are commercially available: Water-soluble phenolic resin was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., product number lnb-1135; Water glass was purchased from Jinan Yuanhai Chemical Co., Ltd., industrial grade, model 01; Polyacrylamide was purchased from Hubei Tosoh Chemical Technology Co., Ltd., with a content of 99%, industrial grade, model 002; The composite aluminum foil is obtained by bonding a nylon layer, an aluminum foil layer and a PVC layer with an adhesive, wherein the thickness of the nylon layer is 30 μm, the thickness of the aluminum foil layer is 0.01 mm, the thickness of the PVC layer is 20 μm, the adhesive is DowDuPont Nucrel 0403, and the amount of adhesive is 1.5 g / m 2 . Example

[0029] Example 1 A medicinal aluminum foil surface coated with iodine-blocking coating, the raw materials and their corresponding weights are shown in Table 1, and the coating is prepared by the following method: (1) preparing raw materials including acrylic resin, water, ethanol, isopropanol, water-soluble phenolic resin and water glass according to a proportion; (2) mixing the acrylic resin, ethanol and isopropanol in step (1) to obtain material A; mixing the water, water glass and water-soluble phenolic resin in step (1) to obtain material B; (3) After mixing material A and material B in step (2), stirring, dispersing and grinding are performed to obtain an iodine-blocking coating for coating the surface of the medicinal aluminum foil.

[0030] Note: In the above steps, the average molecular weight of the acrylic resin is 7000.

[0031] Example 2-3 A medicinal aluminum foil surface coated with an iodine-blocking coating is different from Example 1 in that its preparation raw materials and their corresponding weights are shown in Table 1.

[0032] Table 1 Raw materials and their corresponding weights in Examples 1-3 (kg / portion) raw material Example 1 Example 2 Example 3 Acrylic resin 27.5 25 30 water 45 25 65 Ethanol 5.5 1 10 Isopropyl alcohol 5.5 1 10 Water-soluble phenolic resin 2 1 3 Water Glass 3.5 2 5 Example 4 An iodine-blocking coating is applied on the surface of a medicinal aluminum foil, which is different from Example 1 in that the average molecular weight of the acrylic resin is 6000.

[0033] Example 5 An iodine-blocking coating is applied on the surface of a medicinal aluminum foil, which is different from Example 1 in that the average molecular weight of the acrylic resin is 8,000.

[0034] Example 6 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 1 in that the total amount of water-soluble phenolic resin and water glass remains unchanged, and the weight ratio of the two is adjusted to 2:3.

[0035] Example 7 A medicinal aluminum foil surface coated with iodine-blocking coating, which is different from Example 1 in that 5 parts by weight of functional additives are also added to the raw materials, the functional additives are composed of nanocellulose fibers and porous diatomaceous earth in a weight ratio of 5:1, and the functional additives are added together with water glass and water-soluble phenolic resin. At the same time, the diameter of the nanocellulose fibers is 55nm and the length is 35 microns; the average pore size of the porous diatomaceous earth is 75.nm and the particle size is 7 microns.

[0036] Example 8 An iodine-blocking coating is applied to the surface of a medicinal aluminum foil, which is different from Example 7 in that the weight portion of the functional auxiliary agent added is 4 parts.

[0037] Example 9 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that the weight portion of the functional additive added is 6 parts.

[0038] Example 10 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that the functional additive consists of nanocellulose fibers and porous diatomaceous earth in a weight ratio of 3:1.

[0039] Embodiment 11 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that the functional additive is composed of nanocellulose fibers and porous diatomaceous earth in a weight ratio of 7:1.

[0040] Example 12 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that the diameter of the nanocellulose fiber is 10 nm and the length is 20 microns; the average pore size of the porous diatomaceous earth is 500 nm and the particle size is 4 microns.

[0041] Example 13 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that the diameter of the nanocellulose fiber is 100 nm and the length is 50 microns; the average pore size of the porous diatomaceous earth is 1000 nm and the particle size is 10 microns.

[0042] Embodiment 14 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that no nanocellulose fibers are used in the raw materials.

[0043] Embodiment 15 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 7 in that porous diatomaceous earth is not used in the raw materials.

[0044] Example 16 The invention discloses a medicinal aluminum foil surface coated with an iodine-blocking coating, which is different from the embodiment 1 in that 0.75 parts by weight of polyacrylamide is also added to the raw materials, and the polyacrylamide is added together with water glass and water-soluble phenolic resin.

[0045] Embodiment 17 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 16 in that 0.5 parts by weight of polyacrylamide is also added to the raw materials.

[0046] Embodiment 18 A medicinal aluminum foil surface is coated with an iodine-blocking coating, which is different from Example 16 in that 1 part by weight of polyacrylamide is also added to the raw materials.

[0047] Embodiment 19 A medicinal aluminum foil comprises a composite aluminum foil and an iodine-blocking coating on the surface of the composite aluminum foil, wherein the iodine-blocking coating is obtained by coating and drying the iodine-blocking coating on the surface of the medicinal aluminum foil, and the coating dry weight of the iodine-blocking coating on the surface of the medicinal aluminum foil is 0.8 g / m 2 After coating, it is dried at 170°C for 10 seconds and then placed at room temperature for 10 minutes to form an iodine-resistant coating; the composite aluminum foil is obtained by bonding a nylon layer, an aluminum foil layer and a PVC layer with an adhesive.

[0048] Comparative Example Comparative Example 1 The invention discloses a medicinal aluminum foil surface coated with an iodine-resistant coating, which is different from Example 1 in that no water-soluble phenolic resin is used in the raw materials.

[0049] Comparative Example 2 The invention discloses a medicinal aluminum foil surface coated with an iodine-blocking coating, which is different from Example 1 in that water glass is not used in the raw materials.

[0050] Comparative Example 3 The invention discloses a medicinal aluminum foil surface coated with an iodine-blocking coating, which is different from Example 1 in that water glass and water-soluble phenolic resin are not used in the raw materials.

[0051] Comparative Example 4 A medicinal aluminum foil surface is coated with an iodine-resistant coating, which is different from Example 7 in that water glass and water-soluble phenolic resin are not used in the raw materials.

[0052] Comparative Example 5 A medicinal aluminum foil surface is coated with an iodine-resistant coating, which is different from Example 16 in that water glass and water-soluble phenolic resin are not used in the raw materials.

[0053] Performance test samples: The surfaces of the medicinal aluminum foils in Examples 1-18 and Comparative Examples 1-5 were coated with iodine-blocking coatings, and applied according to the specifications of the medicinal aluminum foils in Example 19, respectively, to obtain test samples 1-18 and control samples 1-5.

[0054] Test method: The commercially available 1.5mg x 24 tablets of cediridine tablets (National Medicine Standard No. H20066174) from CSPC Pharmaceutical Group were used as the test drug; First, the iodine content of the test drug was determined according to the iodine value test operating procedures of the 2020 edition of the "Chinese Pharmacopoeia", and the iodine content value was recorded as A; Then, the test drug is sealed and wrapped with medical aluminum foil, and placed in a high-low temperature alternating test box, with the initial temperature of 25°C, first heated to 45°C at 3°C / min, then cooled to 5°C at 1.5°C / min, and then heated to 25°C at 2°C / min, which is recorded as 1 cycle, and continued for 15 cycles; the iodine content of the test drug is measured in the same way as above, and the iodine content value is recorded as B; Finally, the loss rate of iodine content is calculated. The loss rate of iodine content = (AB) / A. The greater the loss rate of iodine content, the better the application stability of the iodine-resistant coating on the surface of the medicinal aluminum foil under the influence of drastic temperature changes.

[0055] After completing the test samples 1-18 and the control samples 1-5 according to the above test method, the test results are recorded in Table 2 accordingly.

[0056] Table 2 Test results of test samples 1-18 and control samples 1-5 From Example 1 and Comparative Examples 1-3 and Table 2, it can be seen that the application uses water-soluble phenolic resin and water glass in coating the iodine-resistant coating on the surface of the medicinal aluminum foil, so that the stability of the coating formed by the application of the iodine-resistant coating on the surface of the medicinal aluminum foil is significantly improved under the influence of drastic temperature changes, thereby exerting an excellent and stable iodine-resistant effect, and the loss rate of the iodine content value of the medicinal aluminum foil finally obtained after testing is also significantly reduced; while if only water-soluble phenolic resin or water glass is used alone in coating the iodine-resistant coating on the surface of the medicinal aluminum foil, although the temperature-resistant stability of the formed coating can be improved, the improvement effect is limited, and the sum of the improvement effects brought by the application of the two separately is far less than the excellent improvement effect brought by the combination of the two. It can be seen that the combination of water-soluble phenolic resin and water glass can bring a significant improvement effect of 1+1>2, thereby enabling the iodine-resistant coating on the surface of the composite aluminum foil to exert a relatively excellent and stable iodine-resistant effect under drastic temperature changes.

[0057] It can be seen from Example 1 and Examples 4-5 and Table 2 that in the raw materials for coating the iodine-resistant coating on the surface of the medicinal aluminum foil, the average molecular weight of the acrylic resin selected is 6000-8000, which can make the coating formed by coating the iodine-resistant coating on the surface of the medicinal aluminum foil show strong application stability under drastic temperature changes.

[0058] It can be seen from Examples 1-3 and 6 and Table 2 that the weight ratio of the water-soluble phenolic resin to water glass is 2:3, so that the composite effect between the two is better. The iodine-blocking coating on the surface of the obtained medicinal aluminum foil can also exert a relatively excellent and stable iodine-blocking effect under drastic temperature changes after application.

[0059] In conjunction with Example 1 and Example 7-11 and in conjunction with Table 2, it can be seen that by adding a functional additive consisting of nanocellulose fiber and porous diatomite, the application stability of the iodine-blocking coating on the surface of medicinal aluminum foil under severe temperature changes can be significantly improved, and the loss rate of the iodine content value obtained by the test of the medicinal aluminum foil is finally obtained, and it is also further significantly reduced. In conjunction with Example 14-15 and in conjunction with Table 2, it can be seen that if only nanocellulose fiber or porous diatomite is added, although the loss rate of the iodine content value obtained by the test can be reduced, the effect is limited, and the sum of the corresponding effects brought by each of the two is also far less than the excellent use of the two composites, which shows that nanocellulose fiber and porous diatomite can play an excellent composite synergistic effect. In conjunction with Example 12-13 and in conjunction with Table 2, it can be seen that the diameter of nanocellulose fiber is 10-100nm, the length is 20-50 microns, the average pore size of porous diatomite is 500-1000nm, and the particle size is 4-10 microns, which can make the corresponding lifting effect brought by the application of functional additives perform more stably and excellently. Combined with Comparative Examples 2-4 and Table 2, it can be seen that if the iodine-blocking coating on the surface of the medicinal aluminum foil lacks the use of water glass and water-soluble phenolic resin, the corresponding improvement effect brought by the functional additives will be greatly reduced, indicating that the combination of nanocellulose fibers and porous diatomaceous earth and the combination system of water glass and water-soluble phenolic resin have a complex synergistic effect, so that the iodine-blocking effect brought by the coating can be more stably and effectively exerted.

[0060] It can be seen from Example 1 and Examples 16-18 in combination with Table 2 that by using polyacrylamide, the stability of the iodine-blocking coating on the surface of the medicinal aluminum foil under drastic temperature changes can be significantly enhanced, so that the iodine-blocking effect brought by the coating can be more stably and effectively exerted; in combination with Comparative Examples 2 and 5 in combination with Table 2, it can be seen that the excellent effect of polyacrylamide is inseparable from the coordination between water glass and water-soluble phenolic resin, which means that polyacrylamide can enhance the gel system formed by the coordination between water glass and water-soluble phenolic resin, and bring about a significant improvement in the temperature resistance stability of the coating.

[0061] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A medicinal aluminum foil surface coated with iodine-blocking coating, characterized in that: Made from the following raw materials in parts by weight: Acrylic resin 25-30 parts; 25-65 parts water; 1-10 parts of ethanol; 1-10 parts of isopropyl alcohol; 1-3 parts of water-soluble phenolic resin; 2-5 parts of water glass.

2. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 1, characterized in that: The weight ratio of the water-soluble phenolic resin to water glass is 2:

3.

3. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 1, characterized in that: The average molecular weight of the acrylic resin is 6000-8000.

4. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 1, characterized in that: The raw material is also added with 4-6 parts by weight of a functional additive, wherein the functional additive is composed of nano cellulose fibers and porous diatomaceous earth, and the weight ratio of the nano cellulose fibers to the porous diatomaceous earth is (3-7):

1.

5. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 4, characterized in that: The weight ratio of the nanocellulose fibers to the porous diatomaceous earth is 5:

1.

6. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 4, characterized in that: The diameter of the nanocellulose fiber is 10-100 nm and the length is 20-50 microns; the average pore size of the porous diatomaceous earth is 500-1000 nm and the particle size is 4-10 microns.

7. The iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 1, characterized in that: 0.5-1 part by weight of polyacrylamide is also added into the raw materials.

8. The method for preparing the iodine-blocking coating on the surface of the medicinal aluminum foil according to claim 1, characterized in that: The following steps are involved: (1) preparing raw materials including acrylic resin, water, ethanol, isopropyl alcohol, water-soluble phenolic resin and water glass according to a proportion; (2) Mixing the acrylic resin, ethanol and isopropanol in step (1) to obtain material A; Mixing the water, water glass and water-soluble phenolic resin in step (1) to obtain material B; (3) After mixing material A and material B in step (2), stirring, dispersing and grinding are performed to obtain an iodine-blocking coating for coating the surface of a medicinal aluminum foil.

9. A medicinal aluminum foil, characterized in that: It comprises a composite aluminum foil and an iodine-blocking coating on the surface of the composite aluminum foil, wherein the iodine-blocking coating is obtained by coating the surface of any medicinal aluminum foil in claims 1-7 with the iodine-blocking coating and drying the coating.

10. The medicinal aluminum foil according to claim 9, characterized in that: The composite aluminum foil is obtained by bonding a nylon layer, an aluminum foil layer and a PVC layer with an adhesive.

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