High-strength polyvinyl chloride solid pharmaceutical hard tablet and manufacturing process thereof

Abstract

This invention discloses a high-strength polyvinyl chloride (PVC) solid pharmaceutical rigid sheet and its manufacturing process, relating to the field of PVC technology. The manufacturing process includes the following steps: mixing PVC resin, plasticizer, modified core-shell particles, magnesium stearate, antioxidant, light stabilizer, and calcium-zinc heat stabilizer; preheating and then melting the mixture; extruding and granulating the mixture to obtain high-strength PVC granules; placing the high-strength PVC granules in a calender and calendering them to obtain a high-strength PVC solid pharmaceutical rigid sheet. This invention, through the design and compounding of modified core-shell particles and specific plasticizers, forms a complementary reinforcing network in the PVC matrix, achieving a synergistic effect and improving the mechanical properties of the PVC rigid sheet, such as elongation at break and impact resistance, thus possessing significant industrial value.

Description

Technical Field

[0001] This invention relates to the field of polyvinyl chloride (PVC) technology, specifically to a high-strength PVC solid pharmaceutical rigid sheet and its manufacturing process. Background Technology

[0002] Polyvinyl chloride (PVC) solid pharmaceutical rigid sheets are one of the most widely used materials in the pharmaceutical packaging field, mainly used for blister packaging of solid medicines such as tablets and capsules. They possess excellent transparency, mechanical strength, barrier properties, and thermoforming performance, and are relatively inexpensive, thus making them widely used in the pharmaceutical industry.

[0003] Existing PVC solid pharmaceutical rigid sheets are typically manufactured from PVC resin, plasticizers, heat stabilizers, lubricants, and other additives through processes such as mixing, extrusion, and calendering. To ensure the rigid sheets possess a certain degree of flexibility and processing fluidity, plasticizers, such as dioctyl phthalate (DOP) and other small-molecule plasticizers, are usually added. However, these small-molecule plasticizers tend to migrate and precipitate onto the surface of the rigid sheets during long-term use, leading not only to a decrease in the mechanical properties of the sheets (such as brittleness and cracking) but also potentially contaminating the packaged pharmaceutical products, posing safety hazards. On the other hand, rigid PVC sheets are inherently rigid materials with poor impact resistance, making them prone to cracking or breakage due to drops and compression during transportation, storage, and use. To improve the toughness of rigid PVC sheets, a common method is to add impact modifiers; among these, ACR core-shell particles are widely used due to their good compatibility with PVC and high toughening efficiency. However, the shell of traditional ACR core-shell particles is usually polymethyl methacrylate, which, while ensuring good compatibility with PVC, still has room for improvement in its toughening effect on the PVC matrix. Furthermore, existing ACR particles lack functional groups that synergistically interact with plasticizers and other additives, making it difficult to achieve interface optimization in multi-component systems. In conclusion, developing a solid pharmaceutical rigid sheet of polyvinyl chloride that improves the impact resistance and elongation at break of PVC rigid sheets has significant industrial value and market prospects. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength polyvinyl chloride solid pharmaceutical rigid sheet and its manufacturing process, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A manufacturing process for high-strength polyvinyl chloride (PVC) solid pharmaceutical hard sheets includes the following steps: mixing PVC resin, plasticizer, modified core-shell particles, magnesium stearate, antioxidant, light stabilizer, and calcium-zinc heat stabilizer; preheating and then melting the mixture; extruding and granulating the mixture to obtain high-strength PVC granules; placing the high-strength PVC granules in a calender and calendering them to obtain high-strength PVC solid pharmaceutical hard sheets; Preferably, the modified core-shell particles are prepared by introducing polyurethane into polyacrylate-based core-shell particles; Preferably, the mass ratio of plasticizer to modified core-shell particles is 1:(0.3-1).

[0006] More preferably, the high-strength polyvinyl chloride solid pharmaceutical rigid sheet comprises the following raw materials: by weight, 80-100 parts polyvinyl chloride resin, 15-30 parts plasticizer, 8-15 parts modified core-shell particles, 0.8-1.2 parts magnesium stearate, 0.5-0.8 parts antioxidant, 0.3-0.5 parts light stabilizer and 2-3 parts calcium-zinc heat stabilizer; Preferably, preheating is performed at 40-50℃ for 30-50 minutes; smelting is performed at 180-190℃ with stirring for 5-10 minutes. Preferably, the plasticizer is prepared by: placing 2-hydroxyethyl acrylate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, n-hexane and ethanol in a reactor, degassing with liquid nitrogen, adding vinyl chloride, stirring and heating to 45°C, reacting for 1 hour, then adding 2-hydroxyethyl acrylate for semi-batch copolymerization, centrifuging, purifying and drying after polymerization, mixing with 1,4-dioxane, diphenyl phosphate and α-caprolactone, deoxygenating through a freeze-pump-thaw cycle three times, heating in a water bath to 45°C and stirring for 8 hours, adding dichloromethane to precipitate, purifying and drying to obtain the plasticizer; Preferably, the plasticizer comprises the following raw materials: 0.3-1 parts 2-hydroxyethyl acrylate, 0.25-0.3 parts bis(4-tert-butylcyclohexyl) peroxide, 12-15 parts vinyl chloride, 0.2-0.5 parts diphenyl phosphate, and 1.8-8 parts α-caprolactone; Preferably, the steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, modified polycaprolactone diol, hexamethylene diisocyanate, and dibutyltin dilaurate are heated to 80-90℃ and reacted for 1-2 hours. Then, the temperature is lowered to 45-55℃, and 2-hydroxyethyl acrylate is added. The mixture is stirred for 30-50 minutes to obtain a polycaprolactone-polyurethane prepolymer. The polycaprolactone-polyurethane prepolymer is mixed with butyl acrylate, sodium bicarbonate, sodium dodecyl sulfate, and deionized water to obtain a polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix butyl acrylate, allyl methacrylate, ammonium persulfate, sodium bicarbonate, sodium dodecyl sulfate and deionized water, stir and heat to 75-80℃, react for 20-30 min, add the polycaprolactone-polyurethane prepolymer emulsion prepared in Step 1 dropwise and add ammonium persulfate, react for 2-3 h, add a mixed solution of methyl methacrylate and 2-hydroxyethyl acrylate dropwise, add ammonium persulfate and continue the reaction for 2-3 h, cool and add ethanol for freeze demulsification, dry to obtain modified core-shell particles; Preferably, the polycaprolactone-polyurethane prepolymer emulsion in step 1 comprises the following raw materials: by weight, 1.5-2 parts modified polycaprolactone diol, 0.5-1 part hexamethylene diisocyanate, 0.2-0.3 parts 2-hydroxyethyl acrylate, 6-10 parts butyl acrylate, 0.01-0.02 parts sodium bicarbonate, 0.1-0.15 parts sodium dodecyl sulfate, and 15-20 parts deionized water; Preferably, the modified core-shell particles in step 2 include the following raw materials: by mass, 0.6-1 parts butyl acrylate, 0.03-0.05 parts allyl methacrylate, 2.0-4.5 parts methyl methacrylate, 0.8-1.2 parts 2-hydroxyethyl acrylate, and 20-35 parts polycaprolactone-polyurethane prepolymer emulsion; Preferably, the preparation steps of modified polycaprolactone diol are as follows: bis(2-hydroxyethyl) disulfide, α-caprolactone and stannous octoate are mixed, heated to 100°C under a nitrogen atmosphere, reacted for 20 h, and then dissolved, precipitated, filtered and dried to obtain modified polycaprolactone diol. More preferably, the molar ratio of bis(2-hydroxyethyl) disulfide to α-caprolactone is 1:2.

[0007] A high-strength polyvinyl chloride solid pharmaceutical hard sheet is produced by the above-mentioned manufacturing process.

[0008] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention involves a semi-batch copolymerization of vinyl chloride and 2-hydroxyethyl acrylate to introduce hydroxyl groups into the polyvinyl chloride backbone. These hydroxyl groups are then used as initiators to initiate the ring-opening polymerization of caprolactone, which acts as a plasticizer. This plasticizer exhibits good compatibility with the matrix material, achieving a plasticizing effect. By incorporating certain PCL segments, the plasticizer itself possesses a certain degree of crystallinity and strength. This process aims to achieve plasticization while minimizing the sacrifice of toughness, thus ensuring good mechanical properties. This invention further incorporates modified core-shell particles, which are obtained by ring-opening polymerization of bis(2-hydroxyethyl) disulfide and α-caprolactone to introduce disulfide bonds into the PCL segments, resulting in modified polycaprolactone diol. This prepolymer is then used to construct a polyurethane prepolymer, which is finally obtained through seed emulsion polymerization. The introduction of disulfide bonds increases the crosslinking density of the shell polymer network, which in turn improves particle stability, thus achieving a toughening effect. The introduction of hydroxyl groups into the shell forms hydrogen bonds with the PVC matrix and plasticizer, enhancing interfacial bonding and ensuring uniform particle dispersion while effectively transferring impact energy to the core-shell particles, achieving stress dissipation. The modified core-shell particles and a specific plasticizer are designed and compounded to form a complementary reinforcing network in the PVC matrix, achieving a synergistic effect and improving the mechanical properties of PVC rigid sheets, such as elongation at break and impact resistance. This invention uses a compound combination of polyvinyl chloride resin, plasticizer, modified core-shell particles, magnesium stearate, antioxidant, light stabilizer, and calcium-zinc heat stabilizer to achieve excellent processing performance. Detailed Implementation

[0009] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include: The plasticizer was prepared by placing 0.5 parts of 2-hydroxyethyl acrylate, 0.3 parts of bis(4-tert-butylcyclohexyl) peroxide, 100 parts of n-hexane, and 20 parts of ethanol in a reactor. After degassing with liquid nitrogen, 15 parts of vinyl chloride were added, the mixture was stirred, heated to 45°C, and reacted for 1 hour. Then, a total of 0.5 parts of 2-hydroxyethyl acrylate was added for semi-batch copolymerization. After polymerization, the mixture was centrifuged, purified, and dried, and then mixed with 50 parts of 1,4-dioxane, 0.5 parts of diphenyl phosphate, and 5 parts of α-caprolactone. After three cycles of freezing-pumping-thawing for deoxygenation, the mixture was heated to 45°C in a water bath and stirred for 8 hours. Dichloromethane was added to precipitate the mixture, and after purification and drying, the plasticizer was obtained. The semi-batch copolymerization process parameters were as follows: 0.1 g of 2-hydroxyethyl acrylate was added every 1 hour until the reaction was completed after 4 hours, and then another 0.1 g of 2-hydroxyethyl acrylate was added for 2 hours to complete the reaction.

[0011] The preparation steps of modified polycaprolactone diol are as follows: 15 parts of bis(2-hydroxyethyl) disulfide, 22 parts of α-caprolactone and 0.20 parts of stannous octoate are mixed, heated to 100℃ under nitrogen atmosphere, reacted for 20h, and then dissolved, precipitated, filtered and dried to obtain modified polycaprolactone diol.

[0012] Polyvinyl chloride resin TL800; antioxidant 1024, light stabilizer 770, calcium-zinc heat stabilizer ZS-CZ118; In the following examples, parts refer to parts by weight, and all raw materials mentioned above and others not mentioned are commercially available.

[0013] Example 1: This example provides a manufacturing process for high-strength polyvinyl chloride, including the following steps: 100 parts of polyvinyl chloride resin, 18 parts of plasticizer, 12 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.4 parts of light stabilizer and 2.5 parts of calcium zinc heat stabilizer were mixed, dried at 50°C for 40 min, heated to 180°C and stirred and melted for 8 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 1.5 parts by weight of modified polycaprolactone diol, 0.5 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 1.5 hours, cool down to 50°C, add 0.2 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 8 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water and mix to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 0.6 parts butyl acrylate, 0.03 parts allyl methacrylate, 0.02 parts ammonium persulfate, 0.02 parts sodium bicarbonate, 0.1 parts sodium dodecyl sulfate, and 20 parts deionized water, stir, and heat to 75°C. React for 25 minutes. Add the polycaprolactone-polyurethane prepolymer emulsion prepared in Step 1 dropwise and add 0.05 parts ammonium persulfate. After reacting for 2 hours, add a mixed solution of 2.5 parts methyl methacrylate and 1 part 2-hydroxyethyl acrylate dropwise, add 0.03 parts ammonium persulfate, and continue reacting for 2 hours. After cooling, add ethanol for cryogenic demulsification, wash, and dry to obtain modified core-shell particles.

[0014] Example 2: This example provides a manufacturing process for high-strength polyvinyl chloride, including the following steps: 100 parts of polyvinyl chloride resin, 15 parts of plasticizer, 8 parts of modified core-shell particles, 0.8 parts of magnesium stearate, 0.5 parts of antioxidant, 0.3 parts of light stabilizer and 2 parts of calcium-zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 180°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 1 part modified polycaprolactone diol, 0.5 parts hexamethylene diisocyanate and 0.01 parts dibutyltin dilaurate by weight, heat to 85℃ and react for 1.5 h, then cool to 50℃, add 0.2 parts 2-hydroxyethyl acrylate and continue stirring for 30 min to obtain polycaprolactone-polyurethane prepolymer. Add 8 parts butyl acrylate, 0.01 parts sodium bicarbonate, 0.1 parts sodium dodecyl sulfate and 20 parts deionized water and mix to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 0.6 parts butyl acrylate, 0.03 parts allyl methacrylate, 0.02 parts ammonium persulfate, 0.02 parts sodium bicarbonate, 0.1 parts sodium dodecyl sulfate, and 20 parts deionized water, stir, and heat to 75°C. React for 25 min. Add the polycaprolactone-polyurethane prepolymer emulsion prepared in Step 1 dropwise and add 0.05 parts ammonium persulfate. After reacting for 2 h, add a mixed solution of 2.0 parts methyl methacrylate and 0.8 parts 2-hydroxyethyl acrylate dropwise, add 0.03 parts ammonium persulfate, and continue reacting for 2 h. After cooling, add ethanol for cryogenic demulsification, wash, and dry to obtain modified core-shell particles.

[0015] Example 3: This example provides a manufacturing process for high-strength polyvinyl chloride, including the following steps: 100 parts of polyvinyl chloride resin, 28 parts of plasticizer, 12 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.5 parts of light stabilizer and 3 parts of calcium-zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 190°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 2 parts by weight of modified polycaprolactone diol, 0.8 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 2 hours, cool down to 55°C, add 0.3 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 10 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 1 part butyl acrylate, 0.05 part allyl methacrylate, 0.02 part ammonium persulfate, 0.02 part sodium bicarbonate, 0.1 part sodium dodecyl sulfate and 20 parts deionized water, stir and heat to 75°C, react for 25 min, add the polycaprolactone-polyurethane prepolymer prepared in Step 1 dropwise and add 0.05 part ammonium persulfate, react for 2 h, add 4.0 part methyl methacrylate and 1.0 part 2-hydroxyethyl acrylate mixed solution dropwise, add 0.03 part ammonium persulfate and continue to react for 2 h, cool and add ethanol for freeze demulsification, wash and dry to obtain modified core-shell particles.

[0016] Example 4: This example provides a manufacturing process for high-strength polyvinyl chloride, including the following steps: 100 parts of polyvinyl chloride resin, 30 parts of plasticizer, 8 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.4 parts of light stabilizer and 2.5 parts of calcium zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 190°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 2 parts by weight of modified polycaprolactone diol, 0.8 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 2 hours, cool down to 55°C, add 0.3 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 10 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 1 part butyl acrylate, 0.05 part allyl methacrylate, 0.02 part ammonium persulfate, 0.02 part sodium bicarbonate, 0.1 part sodium dodecyl sulfate and 20 parts deionized water, stir and heat to 75°C, react for 25 min, add the polycaprolactone-polyurethane prepolymer prepared in Step 1 dropwise and add 0.05 part ammonium persulfate, react for 2 h, add 4.0 part methyl methacrylate and 1.0 part 2-hydroxyethyl acrylate mixed solution dropwise, add 0.03 part ammonium persulfate and continue to react for 2 h, cool and add ethanol for freeze demulsification, wash and dry to obtain modified core-shell particles.

[0017] Example 5: This example provides a manufacturing process for high-strength polyvinyl chloride, including the following steps: 100 parts of polyvinyl chloride resin, 15 parts of plasticizer, 15 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.5 parts of light stabilizer and 3 parts of calcium-zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 190°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 2 parts by weight of modified polycaprolactone diol, 0.8 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 2 hours, cool down to 55°C, add 0.3 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 10 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 1 part butyl acrylate, 0.05 part allyl methacrylate, 0.02 part ammonium persulfate, 0.02 part sodium bicarbonate, 0.1 part sodium dodecyl sulfate and 20 parts deionized water, stir and heat to 75°C, react for 25 min, add the polycaprolactone-polyurethane prepolymer prepared in Step 1 dropwise and add 0.05 part ammonium persulfate, react for 2 h, add 4.0 part methyl methacrylate and 1.0 part 2-hydroxyethyl acrylate mixed solution dropwise, add 0.03 part ammonium persulfate and continue to react for 2 h, cool and add ethanol for freeze demulsification, wash and dry to obtain modified core-shell particles.

[0018] Comparative Example 1: As a control experiment for Example 3, no modified core-shell particles were added. The specific preparation steps were as follows: 100 parts of polyvinyl chloride resin, 28 parts of plasticizer, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.5 parts of light stabilizer and 3 parts of calcium zinc heat stabilizer were mixed, dried at 50°C for 30 minutes, heated to 190°C and stirred and melted for 5 minutes, and then extruded and granulated to obtain high-strength polyvinyl chloride granules.

[0019] Comparative Example 2: As a control experiment for Example 3, the modified polycaprolactone diol was replaced with polycaprolactone diol with an average Mn of 2000; the specific preparation steps were as follows: 100 parts of polyvinyl chloride resin, 28 parts of plasticizer, 12 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.5 parts of light stabilizer and 3 parts of calcium-zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 190°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 2 parts by weight of polycaprolactone diol, 0.8 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 2 hours, cool down to 55°C, add 0.3 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 10 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 1 part butyl acrylate, 0.05 part allyl methacrylate, 0.02 part ammonium persulfate, 0.02 part sodium bicarbonate, 0.1 part sodium dodecyl sulfate and 20 parts deionized water, stir and heat to 75°C, react for 25 min, add the polycaprolactone-polyurethane prepolymer prepared in Step 1 dropwise and add 0.05 part ammonium persulfate, react for 2 h, add 4.0 part methyl methacrylate and 1.0 part 2-hydroxyethyl acrylate mixed solution dropwise, add 0.03 part ammonium persulfate and continue to react for 2 h, cool and add ethanol for freeze demulsification, wash and dry to obtain modified core-shell particles.

[0020] Comparative Example 3: As a control experiment for Example 3, the amount of plasticizer was increased to 35 parts. The specific preparation steps were as follows: 100 parts of polyvinyl chloride resin, 35 parts of plasticizer, 12 parts of modified core-shell particles, 1.0 part of magnesium stearate, 0.6 parts of antioxidant, 0.5 parts of light stabilizer and 3 parts of calcium-zinc heat stabilizer were mixed, dried at 50°C for 30 min, heated to 190°C and stirred and melted for 5 min, and then extruded and granulated to obtain high-strength polyvinyl chloride granules. The steps for preparing modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, mix 2 parts by weight of modified polycaprolactone diol, 0.8 parts by weight of hexamethylene diisocyanate and 0.01 parts by weight of dibutyltin dilaurate. After heating to 85°C and reacting for 2 hours, cool down to 55°C, add 0.3 parts by weight of 2-hydroxyethyl acrylate and continue stirring for 30 minutes to obtain polycaprolactone-polyurethane prepolymer. Add 10 parts by weight of butyl acrylate, 0.01 parts by weight of sodium bicarbonate, 0.1 parts by weight of sodium dodecyl sulfate and 20 parts by weight of deionized water to obtain polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix 1 part butyl acrylate, 0.05 part allyl methacrylate, 0.02 part ammonium persulfate, 0.02 part sodium bicarbonate, 0.1 part sodium dodecyl sulfate and 20 parts deionized water, stir and heat to 75°C, react for 25 min, add the polycaprolactone-polyurethane prepolymer prepared in Step 1 dropwise and add 0.05 part ammonium persulfate, react for 2 h, add 4.0 part methyl methacrylate and 1.0 part 2-hydroxyethyl acrylate mixed solution dropwise, add 0.03 part ammonium persulfate and continue to react for 2 h, cool and add ethanol for freeze demulsification, wash and dry to obtain modified core-shell particles.

[0021] Performance testing: 1. Take the high-strength polyvinyl chloride granules prepared in Examples 1-5 and Comparative Examples 1-3, place them in a flat vulcanizing machine and press-cut them to obtain impact test strips with specifications of 80×10×4mm and V-notch depth of 2.5mm. Perform impact strength testing in accordance with GB / T1043.1-2008. 2. Take the high-strength polyvinyl chloride granules prepared in Examples 1-5 and Comparative Examples 1-3, place them in a flat vulcanizing machine and cut them into strips by molding. Test their elongation at break according to GB / T 1040.2-2022. In this process, the molding process involves preheating and melting at 180°C, then pressing to 2MPa and holding for 50 seconds, followed by pressing to 10MPa and cooling to demold. Table 1

[0022] Conclusion: The data above show that Example 3 has better overall performance than the other examples; Comparative Example 1, as a control experiment of Example 3, did not add modified core-shell particles, resulting in a significant decrease in impact strength; Comparative Example 2 did not introduce disulfide bonds, resulting in a decrease in the crosslinking density of core-shell particles, a significant decrease in impact strength, and a slight impact on elongation at break; Comparative Example 3 increased the proportion of plasticizer, which improved elongation at break, but significantly reduced impact strength.

[0023] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A manufacturing process for a high-strength polyvinyl chloride solid pharmaceutical rigid sheet, characterized in that, The manufacturing process includes the following steps: mixing polyvinyl chloride resin, plasticizer, modified core-shell particles, magnesium stearate, antioxidant, light stabilizer, and calcium-zinc heat stabilizer, preheating and then melting, extruding and granulating to obtain high-strength polyvinyl chloride granules; placing the high-strength polyvinyl chloride granules in a calender and calendering to obtain high-strength polyvinyl chloride solid pharmaceutical hard sheets; the modified core-shell particles are prepared by introducing polyurethane into polyacrylate-based core-shell particles; the mass ratio of plasticizer to modified core-shell particles is 1:(0.3-1).

2. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 1, characterized in that, The high-strength polyvinyl chloride solid pharmaceutical hard sheet comprises the following raw materials: by weight, 80-100 parts polyvinyl chloride resin, 15-30 parts plasticizer, 8-15 parts modified core-shell particles, 0.8-1.2 parts magnesium stearate, 0.5-0.8 parts antioxidant, 0.3-0.5 parts light stabilizer, and 2-3 parts calcium-zinc heat stabilizer; the preheating is performed at 40-50℃ for 30-50 minutes; the melting is performed at 180-190℃ with stirring for 5-10 minutes.

3. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 1, characterized in that, The plasticizer is prepared by placing 2-hydroxyethyl acrylate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, n-hexane and ethanol in a reactor, degassing with liquid nitrogen, adding vinyl chloride, stirring and heating to 45°C, reacting for 1 hour, then adding 2-hydroxyethyl acrylate for semi-batch copolymerization, centrifuging, purifying and drying after polymerization, and mixing with 1,4-dioxane, diphenyl phosphate and α-caprolactone, deoxygenating through a freeze-pump-thaw cycle three times, heating to 45°C in a water bath and stirring for 8 hours, adding dichloromethane to precipitate, purifying and drying to obtain the plasticizer.

4. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 3, characterized in that, The plasticizer comprises the following raw materials: by weight, 0.3-1 parts 2-hydroxyethyl acrylate, 0.25-0.3 parts bis(4-tert-butylcyclohexyl) peroxide, 12-15 parts vinyl chloride, 0.2-0.5 parts diphenyl phosphate, and 1.8-8 parts α-caprolactone.

5. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 1, characterized in that, The steps for preparing the modified core-shell particles are as follows: Step 1: Under a nitrogen atmosphere, modified polycaprolactone diol, hexamethylene diisocyanate, and dibutyltin dilaurate are heated to 80-90℃ and reacted for 1-2 hours. Then, the temperature is lowered to 45-55℃, and 2-hydroxyethyl acrylate is added. The mixture is stirred for 30-50 minutes to obtain a polycaprolactone-polyurethane prepolymer. The polycaprolactone-polyurethane prepolymer is mixed with butyl acrylate, sodium bicarbonate, sodium dodecyl sulfate, and deionized water to obtain a polycaprolactone-polyurethane prepolymer emulsion. Step 2: Mix butyl acrylate, allyl methacrylate, ammonium persulfate, sodium bicarbonate, sodium dodecyl sulfate, and deionized water, stir, and heat to 75-80℃. React for 20-30 minutes. Add the polycaprolactone-polyurethane prepolymer emulsion prepared in Step 1 dropwise and supplement with ammonium persulfate. After reacting for 2-3 hours, add a mixed solution of methyl methacrylate and 2-hydroxyethyl acrylate dropwise, supplement with ammonium persulfate, and continue the reaction for 2-3 hours. After cooling, add ethanol for cryogenic demulsification, wash, and dry to obtain modified core-shell particles.

6. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 5, characterized in that, The polycaprolactone-polyurethane prepolymer emulsion in step 1 comprises the following raw materials: by weight, 1.5-2 parts modified polycaprolactone diol, 0.5-1 parts hexamethylene diisocyanate, 0.2-0.3 parts 2-hydroxyethyl acrylate, 6-10 parts butyl acrylate, 0.01-0.02 parts sodium bicarbonate, 0.1-0.15 parts sodium dodecyl sulfate, and 15-20 parts deionized water.

7. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 5, characterized in that, The modified core-shell particles in step 2 include the following raw materials: by mass, 0.6-1 parts butyl acrylate, 0.03-0.05 parts allyl methacrylate, 2.0-4.5 parts methyl methacrylate, 0.8-1.2 parts 2-hydroxyethyl acrylate, and 20-35 parts polycaprolactone-polyurethane prepolymer emulsion.

8. The manufacturing process of a high-strength polyvinyl chloride solid pharmaceutical rigid sheet according to claim 5, characterized in that, The modified polycaprolactone diol is prepared by mixing bis(2-hydroxyethyl) disulfide, α-caprolactone and stannous octoate, heating to 100°C under a nitrogen atmosphere, reacting for 20 hours, dissolving, precipitating, filtering and drying to obtain the modified polycaprolactone diol; the molar ratio of bis(2-hydroxyethyl) disulfide to α-caprolactone is 1:

2.

9. A high-strength polyvinyl chloride solid pharmaceutical rigid sheet, characterized in that, It is manufactured by the manufacturing process described in any one of claims 1-8.

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