Medicinal composite hard tablet and preparation method thereof

Abstract

The invention discloses a medicinal composite hard tablet and a preparation method thereof. On one hand, the invention provides a medicinal composite hard sheet which comprises an outer-layer sheet and an inner-layer sheet, the outer layer sheet is prepared from the following raw material components in parts by mass: 100 parts of PET resin, 30 to 40 parts of IPDI polyurethane prepolymer, 6 to 10 parts of compatilizer, 4 to 8 parts of nano titanium dioxide, 4 to 8 parts of silicone powder, 30 to 36 parts of nano montmorillonite and 24 to 30 parts of carbon black; the inner-layer sheet is prepared from the following raw material components in parts by mass: 30 to 40 parts of medium-density PE resin, 50 to 60 parts of low-density PE resin and 12 to 18 parts of nano titanium dioxide. On the other hand, the invention further provides a preparation method of the medicinal composite hard tablet. The composite hard sheet disclosed by the invention is excellent in oxygen barrier property, excellent in moisture resistance and humidity resistance, excellent in ultraviolet light barrier property, relatively excellent in shading property and low in cost.

Description

Technical Field

[0001] This application relates to the field of pharmaceutical packaging materials technology, and in particular to a pharmaceutical composite rigid sheet and its preparation method. Background Technology

[0002] Pharmaceutical composite rigid sheets are a type of pharmaceutical packaging material used to package various solid or liquid medicines, and come into direct contact with the medicine after packaging. For pharmaceutical packaging, barrier properties are a crucial core performance characteristic, directly affecting the shelf life of the medicine. Existing high-barrier pharmaceutical composite rigid sheets must meet excellent oxygen barrier properties, excellent moisture barrier properties, and excellent ultraviolet light barrier properties; for some photosensitive drugs, the composite rigid sheet also needs to have excellent visible light barrier properties. Based on the excellent oxygen barrier properties of PVDC material, which far exceed those of other existing thermoplastic materials, existing high-barrier pharmaceutical composite rigid sheets are primarily made of PVDC material, combined with PVC and / or PE materials to form composite materials.

[0003] PVDC materials have a complex manufacturing process, and very few manufacturers worldwide are capable of producing them, resulting in extremely high prices, far exceeding those of other commercially available thermoplastic materials. Furthermore, PVDC is a homopolymer with extremely high crystallinity and lacks thermoplastic processing properties. Therefore, its application in pharmaceutical packaging materials typically requires the addition of plasticizers for plasticization modification. The introduction of plasticizers and other additives can lead to precipitation problems, affecting safety during use.

[0004] Therefore, designing a pharmaceutical packaging material with barrier properties similar to PVDC materials, low cost, and excellent thermoplastic processing performance is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In order to solve at least one of the above-mentioned technical problems, and to develop a pharmaceutical packaging material with excellent oxygen barrier properties, excellent moisture barrier and moisture-proof properties, excellent ultraviolet light barrier properties, good light-shielding properties, and low cost, this application provides a pharmaceutical composite rigid sheet and its preparation method.

[0006] On one hand, this application provides a pharmaceutical composite rigid sheet, comprising an outer sheet and an inner sheet; the outer sheet comprises the following components in the following mass ratio: 100 parts PET resin, 30-40 parts IPDI polyurethane prepolymer, 6-10 parts compatibilizer, 4-8 parts nano titanium dioxide, 4-8 parts silicone powder, 30-36 parts nano montmorillonite, and 24-30 parts carbon black; the inner sheet comprises the following components in the following mass ratio: 30-40 parts medium-density PE resin, 50-60 parts low-density PE resin, and 12-18 parts nano titanium dioxide.

[0007] Optionally, the IPDI polyurethane prepolymer is prepared by reacting an IPDI trimer curing agent with a bio-based polyol.

[0008] Optionally, the IPDI trimer curing agent may be selected as Z4470 type IPDI trimer curing agent.

[0009] Optionally, the preparation of the IPDI polyurethane prepolymer includes the following steps: S1-a. Mix IPDI trimer curing agent and bio-based polyol at a mass ratio of 100:30~38 to obtain a mixture; S1-b: Add a mixture of quaternary ammonium salt and quaternary phosphate salt, accounting for 0.25~0.3% of the total mass of the mixture, to the mixture obtained in step S1-a. After thorough mixing, a reaction solution is obtained. S1-c: The reaction solution obtained in step S1-b is stirred and reacted at 85~90℃ for 5~5.5h, then heated to 120~125℃ and reacted for another 0.5~1h. After cooling, IPDI polyurethane prepolymer is obtained.

[0010] Alternatively, in step S1-b, the mixture of quaternary ammonium salt and quaternary phosphorus salt may be tetrabutylammonium bromide and butyltriphenylphosphine chloride.

[0011] Alternatively, the mass ratio of the tetrabutylammonium bromide to butyltriphenylphosphine chloride is 1.5 to 2:1.

[0012] Optionally, the compatibilizer is selected from polyvinylpyrrolidone copolymer.

[0013] Optionally, the raw material components of the outer sheet also include expanded vermiculite powder, wherein the expanded vermiculite powder has a particle size of 50~100μm and is added in an amount of 6~8 parts.

[0014] On the other hand, this application also provides a method for preparing the above-mentioned pharmaceutical composite hard sheet, including the following steps: S1. Prepare IPDI polyurethane prepolymer by thoroughly mixing the raw materials of the outer sheet material other than PET resin to obtain a premix. Add PET resin and premix material to a twin-screw extruder, and then perform hot melt extrusion and granulation to obtain the outer sheet material masterbatch. The temperatures of the six temperature zones of the extruder are set sequentially to 175~180℃, 180~185℃, 185~190℃, 185~190℃, 180~185℃, and 175~180℃. S2. Mix the raw materials of the inner layer sheet and add them to a twin-screw extruder. After hot melt extrusion and granulation, the inner layer sheet masterbatch is obtained. The temperatures of the six temperature zones of the extruder are set to 160~165℃, 165~170℃, 165~175℃, 170~175℃, 175~180℃, and 170~175℃ respectively. S3. The outer sheet masterbatch obtained in step S1 and the inner sheet masterbatch obtained in step S2 are co-extruded together to obtain a pharmaceutical composite hard sheet.

[0015] Optionally, in step S3, the double-layer co-extrusion adopts the following parameters: the temperatures of the six temperature zones from the feed end to the connector of the inner sheet extruder are 160~165℃, 165~175℃, 175~180℃, 180~185℃, 180~185℃, and 175~180℃ respectively; the temperatures of the six temperature zones from the feed end to the connector of the outer sheet extruder and the outer protective layer extruder are 175~180℃, 180~185℃, 185~190℃, 190~195℃, 185~190℃, and 175~180℃ respectively; and the die temperature of the double-layer co-extrusion die head is 175~180℃.

[0016] In summary, the present invention has at least one of the following beneficial technical effects: 1. This application uses PET resin as the substrate of the outer sheet and constructs a dense polyurethane crosslinking network with a specific polyurethane prepolymer. With the physical blending modification of nano-montmorillonite, the oxygen barrier performance of the material is greatly improved, so that the oxygen barrier performance of the outer sheet reaches a level close to that of PVDC material.

[0017] 2. The outer sheet of this application, formed by a resin system of PET resin and a specific polyurethane cross-linked network, has excellent moisture-proof and moisture-proof properties, and its water vapor barrier can reach 100%.

[0018] 3. The composite rigid sheet of this application has an inner layer of PE material, which is compounded with the outer layer through a double-layer co-extrusion process, giving the composite rigid sheet good processing performance and making it easy to heat seal with aluminum foil. In addition, the composite rigid sheet of this application adds carbon black, silicone particles and nano titanium dioxide to the outer layer of the sheet, and together with the nano titanium dioxide added to the inner layer of the sheet, the ultraviolet blocking rate can reach 100%, and the overall light transmittance is less than 5%, which is also very excellent.

[0019] 4. The composite rigid sheet of this application does not contain any plasticizers. The inner sheet material uses pure PE resin and inorganic fillers, so there is no problem with the leaching of any harmful components such as plasticizers, and the safety is also excellent. In addition, the composite rigid sheet of this application uses PET resin and PE resin as the main raw materials. While having high barrier performance, the cost is extremely low. Compared with the existing high barrier rigid sheets of PVDC materials, the cost can be reduced by more than 50%. Detailed Implementation

[0020] The present application will be further described in detail below with reference to the embodiments.

[0021] This application provides a pharmaceutical composite rigid sheet, comprising an outer sheet and an inner sheet; the outer sheet comprises the following components in the following mass ratio: 100 parts PET resin, 30-40 parts IPDI polyurethane prepolymer, 6-10 parts compatibilizer, 4-8 parts nano titanium dioxide, 4-8 parts silicone powder, 30-36 parts nano montmorillonite, and 24-30 parts carbon black; the inner sheet comprises the following components in the following mass ratio: 30-40 parts medium-density PE resin, 50-60 parts low-density PE resin, and 12-18 parts nano titanium dioxide.

[0022] The preparation method of the above-mentioned pharmaceutical composite hard sheet of this application includes the following steps: S1. Prepare IPDI polyurethane prepolymer by thoroughly mixing the raw materials of the outer sheet material other than PET resin to obtain a premix. Add PET resin and premix material to a twin-screw extruder, and then perform hot melt extrusion and granulation to obtain the outer sheet material masterbatch. The temperatures of the six temperature zones of the extruder are set sequentially to 175~180℃, 180~185℃, 185~190℃, 185~190℃, 180~185℃, and 175~180℃. S2. Mix the raw materials of the inner layer sheet and add them to a twin-screw extruder. After hot melt extrusion and granulation, the inner layer sheet masterbatch is obtained. The temperatures of the six temperature zones of the extruder are set to 160~165℃, 165~170℃, 165~175℃, 170~175℃, 175~180℃, and 170~175℃ respectively. S3. The outer sheet masterbatch obtained in step S1 and the inner sheet masterbatch obtained in step S2 are co-extruded together to obtain a pharmaceutical composite hard sheet.

[0023] Prior to this application, existing high-barrier pharmaceutical composite rigid sheets were mainly PVC / PE / PVDC composite rigid sheets and PVDC / PVC composite rigid sheets. Both types of composite rigid sheets utilize PVDC material with high barrier properties. This material has extremely excellent oxygen barrier properties, and through lamination, the composite rigid sheet material can possess excellent overall performance. However, PVDC is expensive, costing one to several times more than commonly used thermoplastic materials, significantly increasing the cost of pharmaceutical packaging materials.

[0024] This application utilizes a specific design, employing low-cost PET resin as the main raw material and a specific polyurethane prepolymer to construct a dense polyurethane cross-linked network, forming a specific resin system. This system is then modified with nano-montmorillonite to produce a composite material. This composite material also possesses excellent oxygen barrier properties, comparable to those of PVDC materials. By combining the aforementioned composite material with PE materials, this application has prepared a pharmaceutical composite rigid sheet, exhibiting excellent comprehensive barrier properties, thermal bonding processing performance, and thermoplastic processing performance. Calculations show that the cost of this pharmaceutical composite rigid sheet is reduced by more than 50% compared to currently commercially available PVDC / PVC composite rigid sheets, significantly reducing pharmaceutical packaging costs.

[0025] The following are preparation examples and embodiments of this application.

[0026] The main raw materials used in the embodiments of this application are all commercially available.

[0027] Among them, PET resin was purchased from Hubei Jusheng Technology Co., Ltd.; Z4470 IPDI trimer curing agent was purchased from Guangzhou Haoyi New Material Technology Co., Ltd.; bio-based polyol, FH-3185, was purchased from Zhangjiagang Feihang Technology Co., Ltd.; rutile nano titanium dioxide, 15~30nm, was purchased from Beijing Deco Island Gold Technology Co., Ltd.; silicone powder, 99% purity, was purchased from [source missing]; nano montmorillonite, particle size 80~200nm, was purchased from Zhejiang Fenghong New Material Co., Ltd.; polyvinylpyrrolidone copolymer, VA64, was purchased from Shanghai Caiyou Industrial Co., Ltd.; carbon black, nano-grade pigment carbon black, was purchased from Henan Hengxincheng Chemical Products Co., Ltd.; medium density PE resin, HDPE Zhejiang Petrochemical 5502, was purchased from Shanghai Chengwei Plastics Co., Ltd.; low density PE resin, LDPE Yanshan Petrochemical LD163 film grade, was purchased from Shanghai Jinsuda Plastics Co., Ltd.

[0028] The following is a preparation example of this application.

[0029] Preparation Example 1 The preparation of the IPDI polyurethane prepolymer in this example includes the following steps: S1-a. Mix IPDI trimer curing agent and bio-based polyol at a mass ratio of 100:30 to obtain a mixture; S1-b: Add a mixture of quaternary ammonium salt and quaternary phosphorus salt (tetrabutylammonium bromide and butyltriphenylphosphine chloride are prepared in a mass ratio of 1.5:1) to the mixture obtained in step S1-a, accounting for 0.25% of the total mass of the mixture. After stirring and mixing thoroughly, a reaction solution is obtained. S1-c: The reaction solution obtained in step S1-b is stirred and reacted at 85~90℃ for 5h, then heated to 120~125℃ and reacted for another 0.5h. After cooling, IPDI polyurethane prepolymer is obtained.

[0030] Preparation Example 2 The preparation of the IPDI polyurethane prepolymer in this example includes the following steps: S1-a. Mix IPDI trimer curing agent and bio-based polyol at a mass ratio of 100:38 to obtain a mixture; S1-b: Add a mixture of quaternary ammonium salt and quaternary phosphorus salt (tetrabutylammonium bromide and butyltriphenylphosphine chloride are prepared in a mass ratio of 1.5:1) to the mixture obtained in step S1-a, accounting for 0.3% of the total mass of the mixture. After stirring and mixing thoroughly, a reaction solution is obtained. S1-c: The reaction solution obtained in step S1-b is stirred and reacted at 85~90℃ for 5h, then heated to 120~125℃ and reacted for another 0.5h. After cooling, IPDI polyurethane prepolymer is obtained.

[0031] Preparation Example 3 The preparation of the IPDI polyurethane prepolymer in this example includes the following steps: S1-a. Mix IPDI trimer curing agent and bio-based polyol at a mass ratio of 100:36 to obtain a mixture; S1-b: Add a mixture of quaternary ammonium salt and quaternary phosphorus salt (tetrabutylammonium bromide and butyltriphenylphosphine chloride are prepared in a mass ratio of 2:1) to the mixture obtained in step S1-a, accounting for 0.28% of the total mass of the mixture. After stirring and mixing thoroughly, a reaction solution is obtained. S1-c: The reaction solution obtained in step S1-b is stirred and reacted at 85~90℃ for 5.5h, then heated to 120~125℃ and reacted for another 1h. After cooling, IPDI polyurethane prepolymer is obtained.

[0032] Preparation Example 4 The preparation of expanded vermiculite micro powder in this example includes the following steps: Sa, the vermiculite was ultrasonically cleaned with deionized water for 30 minutes and dried in an oven at 60°C to constant weight to obtain cleaned vermiculite; Sb. The washed vermiculite from step Sa is subjected to microwave expansion treatment at 400W for 75 seconds, and then ground to a particle size of 50~100μm to obtain expanded vermiculite micro powder.

[0033] The following are embodiments of this application.

[0034] The pharmaceutical composite hard sheet of this application embodiment is prepared by the following method, including the following steps: S1. Select a specific IPDI polyurethane prepolymer, and fully mix the raw materials of the outer sheet material other than PET resin to obtain a premix. Add PET resin and premix material to a twin-screw extruder, and then perform hot melt extrusion and granulation to obtain the outer sheet material masterbatch. The temperatures of the six temperature zones of the extruder are set to 178℃, 182℃, 186℃, 190℃, 184℃, and 178℃ respectively. S2. Mix the raw materials of the inner layer sheet and add them to a twin-screw extruder. After hot melt extrusion and granulation, the inner layer sheet masterbatch is obtained. The temperatures of the six temperature zones of the extruder are set to 164℃, 168℃, 172℃, 175℃, 180℃ and 178℃ respectively. S3. The outer sheet masterbatch obtained in step S1 and the inner sheet masterbatch obtained in step S2 are co-extruded together to obtain a pharmaceutical composite hard sheet. The co-extrusion parameters are as follows: the temperatures of the six temperature zones from the feed end to the connector of the inner sheet extruder are 164℃, 170℃, 178℃, 182℃, 185℃, and 178℃ respectively; the temperatures of the six temperature zones from the feed end to the connector of the outer sheet extruder and the outer protective layer extruder are 176℃, 182℃, 188℃, 195℃, 186℃, and 178℃ respectively; and the die temperature of the co-extrusion die head is 178℃.

[0035] The thickness of the pharmaceutical composite hard sheet prepared in the embodiments of this application is 0.25 mm.

[0036] Example 1 The pharmaceutical composite rigid sheet of this embodiment includes an outer sheet and an inner sheet.

[0037] The mass proportions of each raw material component in the outer sheet material include: 100 parts PET resin, 40 parts IPDI polyurethane prepolymer, 10 parts maleic anhydride grafted polyethylene, 8 parts nano titanium dioxide, 8 parts silicone powder, 36 parts nano montmorillonite, and 30 parts carbon black.

[0038] The mass proportions of the raw material components of the inner layer sheet include: 40 parts of medium-density PE resin, 60 parts of low-density PE resin, and 18 parts of nano-titanium dioxide.

[0039] The IPDI polyurethane prepolymer prepared in Preparation Example 1 was selected.

[0040] Example 2 The pharmaceutical composite rigid sheet of this embodiment includes an outer sheet and an inner sheet.

[0041] The mass proportions of each raw material component in the outer sheet material include: 100 parts PET resin, 30 parts IPDI polyurethane prepolymer, 6 parts maleic anhydride grafted polyethylene, 4 parts nano titanium dioxide, 4 parts silicone powder, 30 parts nano montmorillonite, and 24 parts carbon black.

[0042] The mass proportions of the raw material components of the inner layer sheet include: 30 parts of medium-density PE resin, 50 parts of low-density PE resin, and 12 parts of nano-titanium dioxide.

[0043] The IPDI polyurethane prepolymer prepared in Preparation Example 1 was selected.

[0044] Example 3 The pharmaceutical composite rigid sheet of this embodiment includes an outer sheet and an inner sheet.

[0045] The mass proportions of each raw material component in the outer sheet material include: 100 parts PET resin, 36 parts IPDI polyurethane prepolymer, 8 parts maleic anhydride grafted polyethylene, 6 parts nano titanium dioxide, 6.5 parts silicone powder, 34 parts nano montmorillonite, and 28 parts carbon black.

[0046] The mass proportions of the raw material components of the inner layer sheet include: 36 parts of medium-density PE resin, 54 parts of low-density PE resin, and 16 parts of nano-titanium dioxide.

[0047] The IPDI polyurethane prepolymer prepared in Preparation Example 1 was selected.

[0048] Example 4 The mass proportions of each raw material component in the outer sheet material include: 100 parts PET resin, 36 parts IPDI polyurethane prepolymer, 8 parts polyvinylpyrrolidone copolymer, 6 parts nano titanium dioxide, 6.5 parts silicone powder, 34 parts nano montmorillonite, and 28 parts carbon black.

[0049] The mass proportions of the raw material components of the inner layer sheet include: 36 parts of medium-density PE resin, 54 parts of low-density PE resin, and 16 parts of nano-titanium dioxide.

[0050] The IPDI polyurethane prepolymer prepared in Preparation Example 1 was selected.

[0051] Example 5 The difference between this embodiment and Example 4 is that the IPDI polyurethane prepolymer prepared in Preparation Example 2 is used.

[0052] Example 6 The difference between this embodiment and Example 4 is that the IPDI polyurethane prepolymer prepared in Preparation Example 3 is used.

[0053] Example 7 The difference between this embodiment and Example 6 is that 6 parts of the expanded vermiculite powder prepared in Preparation Example 4 were added to the raw material of the outer sheet.

[0054] Example 8 The difference between this embodiment and Example 6 is that 8 parts of the expanded vermiculite powder prepared in Preparation Example 4 were added to the raw material of the outer sheet.

[0055] Comparative Example 1 This application uses a 0.25mm PVC / PE / PVDC composite sheet produced by Sichuan Huili Industrial Co., Ltd. as comparative example 1.

[0056] Comparative Example 2 This application uses a 0.25mm PVC / PVDC composite sheet produced by Sichuan Huili Industrial Co., Ltd. as comparative example 2.

[0057] Comparative Example 3 Compared with Example 6, this comparative example did not contain nano-montmorillonite.

[0058] Comparative Example 4 Compared with Example 6, this comparative example uses an equal amount of PET resin to replace the IPDI polyurethane prepolymer.

[0059] The overall barrier properties of the products from Examples 1-10 and Comparative Examples 1-4 were tested.

[0060] Among them, the oxygen barrier performance was tested according to the method described in GB / T 19789-2021; The moisture barrier performance was tested according to the water vapor transmission tester method described in GB / T 1037-2021; The light-blocking performance was tested using a transmittance meter to measure the transmittance of the sheet to ultraviolet and visible light, respectively.

[0061] The results are shown in Table 1 below.

[0062] Table 1. Performance test results of Examples 1-10 and Comparative Examples 1-4 after curing.

[0063] As can be seen from the data in Table 1, the pharmaceutical composite rigid sheets prepared in Examples 1-8 of this application have oxygen barrier properties that are basically equivalent to those of existing PVC / PE / PVDC rigid sheets and PVC / PVDC rigid sheets in Comparative Examples 1 and 2, while their moisture barrier properties are slightly better than those of Comparative Examples 1 and 2, and their light-blocking properties are superior to those of Comparative Examples 1 and 2. Therefore, it is evident that the pharmaceutical composite rigid sheets prepared using non-PVDC materials in this application do not have weaker oxygen barrier properties than those made of PVDC materials, and their moisture barrier and light-blocking properties are even better, resulting in overall barrier performance superior to existing PVDC material composite rigid sheets.

[0064] The data in Table 1, comparing the data from Examples 1-8, shows that the performance of the composite rigid sheet can be further improved after adjusting the raw material ratios of the polyurethane prepolymer and the outer sheet. The applicant believes that the polyurethane crosslinking network formed by the specific IPDI polyurethane prepolymer used in this application possesses excellent antioxidant and oxygen barrier properties. Combined with the modification of nano-montmorillonite, the synergistic effect of the two can significantly improve the oxygen barrier performance. Furthermore, the oxygen barrier and light-blocking properties of the composite rigid sheet can be further improved after adding expanded vermiculite powder to the outer sheet. The applicant believes that the excellent porous structure of expanded vermiculite powder, combined with montmorillonite, can construct more complex oxygen barrier pathways, which, combined with the design of the crosslinking resin system in this application, can further improve oxygen barrier performance. However, expanded vermiculite powder has a certain degree of hygroscopicity; excessive addition will affect the moisture barrier performance of the material. Therefore, the amount added should be controlled within the specific ratio specified in this application.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pharmaceutical composite hard sheet, characterized in that, The product comprises an outer sheet and an inner sheet. The outer sheet comprises the following components in the following proportions by weight: 100 parts PET resin, 30-40 parts IPDI polyurethane prepolymer, 6-10 parts compatibilizer, 4-8 parts nano titanium dioxide, 4-8 parts silicone powder, 30-36 parts nano montmorillonite, and 24-30 parts carbon black. The inner sheet comprises the following components in the following proportions by weight: 30-40 parts medium-density PE resin, 50-60 parts low-density PE resin, and 12-18 parts nano titanium dioxide.

2. The pharmaceutical composite hard sheet according to claim 1, characterized in that, The IPDI polyurethane prepolymer is prepared by reacting IPDI trimer curing agent and bio-based polyol.

3. The pharmaceutical composite hard sheet according to claim 2, characterized in that, The IPDI trimer curing agent used is Z4470 type IPDI trimer curing agent.

4. The pharmaceutical composite hard sheet according to claim 2, characterized in that, The preparation of the IPDI polyurethane prepolymer includes the following steps: S1-a. Mix IPDI trimer curing agent and bio-based polyol at a mass ratio of 100:30~38 to obtain a mixture; S1-b: Add a mixture of quaternary ammonium salt and quaternary phosphate salt, accounting for 0.25~0.3% of the total mass of the mixture, to the mixture obtained in step S1-a. After thorough mixing, a reaction solution is obtained. S1-c: The reaction solution obtained in step S1-b is stirred and reacted at 85~90℃ for 5~5.5h, then heated to 120~125℃ and reacted for another 0.5~1h. After cooling, IPDI polyurethane prepolymer is obtained.

5. The pharmaceutical composite hard sheet according to claim 4, characterized in that, In step S1-b, the mixture of quaternary ammonium salt and quaternary phosphorus salt is selected from tetrabutylammonium bromide and butyltriphenylphosphine chloride.

6. The pharmaceutical composite hard sheet according to claim 5, characterized in that, The mass ratio of tetrabutylammonium bromide to butyltriphenylphosphine chloride is 1.5~2:

1.

7. The pharmaceutical composite hard sheet according to claim 1, characterized in that, The compatibilizer is selected from polyvinylpyrrolidone copolymer.

8. The pharmaceutical composite hard sheet according to claim 1, characterized in that, The outer sheet material also includes expanded vermiculite powder, which has a particle size of 50-100 μm and is added in an amount of 6-8 parts.

9. The method for preparing a pharmaceutical composite hard sheet according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Prepare IPDI polyurethane prepolymer by thoroughly mixing the raw materials of the outer sheet material other than PET resin to obtain a premix. Add PET resin and premix material to a twin-screw extruder, and then perform hot melt extrusion and granulation to obtain the outer sheet material masterbatch. The temperatures of the six temperature zones of the extruder are set sequentially to 175~180℃, 180~185℃, 185~190℃, 185~190℃, 180~185℃, and 175~180℃. S2. Mix the raw materials of the inner layer sheet and add them to a twin-screw extruder. After hot melt extrusion and granulation, the inner layer sheet masterbatch is obtained. The temperatures of the six temperature zones of the extruder are set to 160~165℃, 165~170℃, 165~175℃, 170~175℃, 175~180℃, and 170~175℃ respectively. S3. The outer sheet masterbatch obtained in step S1 and the inner sheet masterbatch obtained in step S2 are co-extruded together to obtain a pharmaceutical composite hard sheet.

10. The method for preparing the pharmaceutical composite hard sheet according to claim 9, characterized in that, In step S3, the double-layer co-extrusion adopts the following parameters: the temperatures of the six temperature zones from the feed end to the connector of the inner sheet extruder are 160~165℃, 165~175℃, 175~180℃, 180~185℃, 180~185℃, and 175~180℃ respectively; the temperatures of the six temperature zones from the feed end to the connector of the outer sheet extruder and the outer protective layer extruder are 175~180℃, 180~185℃, 185~190℃, 190~195℃, 185~190℃, and 175~180℃ respectively; and the die temperature of the double-layer co-extrusion die head is 175~180℃.

Images