Modified PVC (polyvinyl chloride) for medical packaging and preparation method thereof

Abstract

The invention discloses modified PVC (polyvinyl chloride) for medical packaging and a preparation method. The formula of the modified PVC comprises PVC resin powder, MBS (methyl methacrylate-butadiene-styrene), ACR (acrylate), an external lubricant, an internal lubricant, a methyl tin stabilizer, biquaternary ammonium salt, EVOH (ethylene vinyl alcohol), dilauryl thiodipropionate, dioctyl adipate and aramid fiber. The preparation method comprises the following steps: step 1, preparing materials; 2, preparing biquaternary ammonium salt; step 3, mixing and pretreatment; step 4, performing multi-layer co-extrusion extension; step 5, molding and curing; and step 6, inspecting and packaging. The biquaternary ammonium salt is used as an antibacterial additive to be added into the PVC material, the biquaternary ammonium salt has broad-spectrum antibacterial property and can effectively kill or inhibit growth of various bacteria, fungi and viruses, the antibacterial activity of the biquaternary ammonium salt is mainly derived from cationic properties of the biquaternary ammonium salt, the cations can interact with negative charges on microbial cell membranes, and the antibacterial activity of the biquaternary ammonium salt is improved. Therefore, the modified PVC material is endowed with lasting antibacterial performance.

Description

Technical Field

[0001] The present invention relates to the technical field of modified PVC, and specifically to a modified PVC for medical packaging and a preparation method thereof. Background Art

[0002] PVC, that is, polyvinyl chloride, is a widely used thermoplastic. It is prepared by the polymerization of vinyl chloride monomers and has excellent physical and chemical properties as well as relatively low costs. Therefore, it is widely used in many fields such as construction, packaging, wire and cable, medical devices, automotive interiors, footwear, furniture, toys, etc. The PVC material has good flexibility and plasticity and can be processed into products of various shapes and sizes through various molding processes such as injection molding, extrusion, blow molding, calendering, etc. Its hardness range is wide, and it can produce products from very soft films to hard pipe materials. In addition, PVC also has good insulation performance and weather resistance and can maintain stable performance within a relatively wide temperature range.

[0003] The existing PVC materials have the following defects: First, the PVC material itself does not have antibacterial ability, which means that during the use of medical packaging, bacteria are likely to adhere to its surface and gradually form a biofilm that is difficult to remove. The formation of the biofilm not only exacerbates the growth of bacteria but may also contaminate the medical devices or drugs inside the packaging, thus increasing the risk of cross-infection. Therefore, the application of traditional PVC materials in the field of medical packaging is greatly limited. Second, there are obvious deficiencies in the barrier performance. Traditional PVC materials have a relatively high permeability to oxygen, water vapor, or other gases, which may cause the medical devices or drugs inside the packaging to be affected by environmental factors such as oxygen and humidity during storage and transportation, resulting in deterioration, degradation, or failure. Third, the tear resistance strength is insufficient, which means that during transportation, storage, or use, the packaging may be broken or torn under the action of external forces such as extrusion and pulling, resulting in the contamination or damage of the items inside the packaging. Summary of the Invention

[0004] The purpose of the present invention is to provide a modified PVC for medical packaging and a preparation method thereof to solve the problems raised in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solutions: A modified PVC for medical packaging, the formula includes: PVC resin powder, MBS, ACR, external lubricant, internal lubricant, methyltin stabilizer, bisquaternary ammonium salt, EVOH, dilauryl thiodipropionate, dioctyl adipate and aramid fiber. The mass percentages of the respective components are: 50% - 70% of PVC resin powder, 5% - 15% of MBS, 0.5% - 2% of ACR, 0.2% - 1% of external lubricant, 0.2% - 1% of internal lubricant, 1% - 3% of methyltin stabilizer, 2% - 5% of bisquaternary ammonium salt, 5% - 20% of EVOH, 0.1% - 1% of dilauryl thiodipropionate, 5% - 15% of dioctyl adipate and 1% - 5% of aramid fiber.

[0006] As a further technical solution of the present invention, the mass percentages of the respective components are: 50% of PVC resin powder, 10% of MBS, 1% of ACR, 1% of external lubricant, 1% of internal lubricant, 2% of methyltin stabilizer, 3% of bisquaternary ammonium salt, 20% of EVOH, 1% of dilauryl thiodipropionate, 8% of dioctyl adipate and 3% of aramid fiber.

[0007] As a further technical solution of the present invention, the mass percentages of the respective components are: 60% of PVC resin powder, 5% of MBS, 0.5% of ACR, 1% of external lubricant, 0.5% of internal lubricant, 1% of methyltin stabilizer, 2% of bisquaternary ammonium salt, 13% of EVOH, 1% of dilauryl thiodipropionate, 15% of dioctyl adipate and 1% of aramid fiber.

[0008] As a further technical solution of the present invention, the mass percentages are: 65% of PVC resin powder, 5% of MBS, 1% of ACR, 0.5% of external lubricant, 1% of internal lubricant, 3% of methyltin stabilizer, 5% of bisquaternary ammonium salt, 5% of EVOH, 0.5% of dilauryl thiodipropionate, 10% of dioctyl adipate and 4% of aramid fiber.

[0009] As a further technical solution of the present invention, the external lubricant is specifically one of calcium stearate and zinc stearate, and the internal lubricant is one of polyethylene wax and oxidized polyethylene wax.

[0010] A preparation method of a modified PVC for medical packaging includes Step 1, material preparation; Step 2, preparation of bisquaternary ammonium salt; Step 3, mixing and pretreatment; Step 4, multi-layer co-extrusion and calendaring; Step 5, forming and curing; Step 6, inspection and packaging.

[0011] Among them, in the above Step 1, prepare the raw materials required for preparing the modified PVC.

[0012] Among them, in the above step two, the double quaternary ammonium salt raw materials required for production are prepared;

[0013] Among them, in the above step three, the raw materials except EVOH are mixed according to the ratio to ensure uniform distribution of each component, and the mixture is preheated;

[0014] Among them, in the above step four, the multi-layer co-extrusion technology is used to add an EVOH layer to the middle layer of PVC;

[0015] Among them, in the above step five, the required packaging shape is made through a forming process and solidification treatment is carried out;

[0016] Among them, in the above step six, the prepared medical packaging materials are strictly inspected, including appearance inspection and performance testing, to ensure that they meet the relevant standards and requirements.

[0017] As a further technical solution of the present invention, in the above step two, long-chain alkylamine is prepared as the main reactant, chloroalkane is selected for quaternization reaction with long-chain alkylamine, acetone is selected as the solvent, and potassium hydroxide is selected as the catalyst.

[0018] As a further technical solution of the present invention, in the above step two, long-chain alkylamine and halogenated hydrocarbon are added to the reaction vessel in a certain proportion, stirred and reacted at an appropriate temperature for a period of time to make the quaternization reaction proceed fully. During the reaction process, the temperature, pressure and stirring speed are controlled. After the reaction is completed, an appropriate amount of hydrochloric acid is added to neutralize the excessive alkali, and the reaction product is washed with water to remove impurities such as unreacted raw materials, solvents and generated salts.

[0019] As a further technical solution of the present invention, in the above step two, the washed product is dried to remove residual moisture, and through concentration operation, the concentration of the product is increased to facilitate subsequent separation and purification. The crystallization separation method is selected to further purify the separated product to improve its purity and obtain the double quaternary ammonium salt.

[0020] As a further technical solution of the present invention, in the above step four, the PVC raw material and EVOH raw material are fed into a multi-layer co-extrusion extruder, heated and melted, and then extruded through the runner of the die. The PVC layer and EVOH layer can be tightly combined at the die outlet, so that the EVOH layer is coated in the middle of the PVC layer. The extruded multi-layer composite material quickly passes through the cooling water tank to reduce the temperature and fix the shape.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention adds a bisquaternary ammonium salt as an antibacterial additive to the PVC material. The bisquaternary ammonium salt has broad-spectrum antibacterial properties and can effectively kill or inhibit the growth of various bacteria, fungi, and viruses. Its antibacterial activity mainly comes from its cationic nature. These cations can interact with the negative charges on the microbial cell membrane, resulting in the destruction of the cell membrane and the death of the microorganisms, endowing the modified PVC material with persistent antibacterial properties, enabling the PVC material to be successfully applied to the field of medical packaging. Moreover, by using the multi-layer co-extrusion method, an EVOH layer is added to the PVC to form a composite PVC packaging material, which improves the barrier properties of the material and prevents medical devices or drugs in the package from being affected by environmental factors such as oxygen and humidity during storage and transportation. At the same time, by adding aramid fiber as a reinforcing fiber and using it to compound with the PVC resin, a composite material with excellent mechanical properties can be formed, significantly enhancing the tear strength of the PVC material and improving the protection ability for the items in the package. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flowchart of the preparation method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Please refer to the appendix Figure 1 , a technical solution provided by the present invention:

[0025] Example 1

[0026] A modified PVC for medical packaging, the formula includes: PVC resin powder, MBS, ACR, external lubricant, internal lubricant, methyltin stabilizer, bisquaternary ammonium salt, EVOH, dilauryl thiodipropionate, dioctyl adipate, aramid fiber. The mass percentages of each component are: 50% of PVC resin powder, 10% of MBS, 1% of ACR, 1% of external lubricant, 1% of internal lubricant, 2% of methyltin stabilizer, 3% of bisquaternary ammonium salt, 20% of EVOH, 1% of dilauryl thiodipropionate, 8% of dioctyl adipate, and 3% of aramid fiber; the external lubricant is calcium stearate, and the internal lubricant is polyethylene wax;

[0027] A preparation method of modified PVC for medical packaging, including Step 1, material preparation; Step 2, preparation of bisquaternary ammonium salt; Step 3, mixing and pretreatment; Step 4, multi-layer co-extrusion calendering; Step 5, forming and curing; Step 6, inspection and packaging;

[0028] In the above Step 1, prepare the raw materials required for preparing modified PVC;

[0029] In the above Step 2, prepare long-chain alkylamine as the main reactant, select chloroalkane for quaternization reaction with long-chain alkylamine, choose acetone as the solvent, potassium hydroxide as the catalyst, add long-chain alkylamine and haloalkane into the reaction vessel in a certain proportion, stir and react at an appropriate temperature for a period of time to make the quaternization reaction proceed fully. Control the temperature, pressure and stirring speed during the reaction. After the reaction is completed, add an appropriate amount of hydrochloric acid to neutralize the excessive alkali, wash the reaction product with water to remove impurities such as unreacted raw materials, solvents and generated salts, dry the washed product to remove residual moisture, and improve the concentration of the product through concentration operation to facilitate subsequent separation and purification. Select the crystallization separation method to further purify the separated product to improve its purity and obtain the bisquaternary ammonium salt;

[0030] In the above Step 3, mix the raw materials except EVOH according to the ratio to ensure uniform distribution of each component, and preheat the mixture;

[0031] In the above Step 4, feed the PVC raw material and EVOH raw material into a multi-layer co-extrusion extruder. After heating and melting, extrude through the runner of the die. The PVC layer and the EVOH layer can be tightly combined at the die outlet, so that the EVOH layer is coated in the middle of the PVC layer. The extruded multi-layer composite material quickly passes through the cooling water tank to reduce the temperature and fix the shape;

[0032] In the above Step 5, make the required packaging shape through the forming process and carry out the curing treatment;

[0033] In the above Step 6, strictly inspect the made medical packaging material, including appearance inspection and performance testing, to ensure that it meets the relevant standards and requirements.

[0034] Example 2

[0035] A modified PVC for medical packaging, the formula includes: PVC resin powder, MBS, ACR, external lubricant, internal lubricant, methyltin stabilizer, bisquaternary ammonium salt, EVOH, dilauryl thiodipropionate, dioctyl adipate, aramid fiber. The mass percentages of each component are: 60% of PVC resin powder, 5% of MBS, 0.5% of ACR, 1% of external lubricant, 0.5% of internal lubricant, 1% of methyltin stabilizer, 2% of bisquaternary ammonium salt, 13% of EVOH, 1% of dilauryl thiodipropionate, 15% of dioctyl adipate and 1% of aramid fiber; the external lubricant is zinc stearate, and the internal lubricant is polyethylene wax oxide; its preparation method is the same as that of Example 1.

[0036] Example 3

[0037] A modified PVC for medical packaging, the formula includes: PVC resin powder, MBS, ACR, external lubricant, internal lubricant, methyltin stabilizer, bisquaternary ammonium salt, EVOH, dilauryl thiodipropionate, dioctyl adipate, aramid fiber. The mass percentages of each component are: 65% of PVC resin powder, 5% of MBS, 1% of ACR, 0.5% of external lubricant, 1% of internal lubricant, 3% of methyltin stabilizer, 5% of bisquaternary ammonium salt, 5% of EVOH, 0.5% of dilauryl thiodipropionate, 10% of dioctyl adipate and 4% of aramid fiber; the external lubricant is calcium stearate, and the internal lubricant is polyethylene wax; its preparation method is the same as that of Example 1.

[0038] Comparative Example 1

[0039] A PVC formula without bisquaternary ammonium salt was used, and the other components were the same as those in Example 1 of the present invention.

[0040] Comparative Example 2

[0041] A PVC formula without EVOH was used, and the other components were the same as those in Example 2 of the present invention.

[0042] Comparative Example 3

[0043] A PVC formula without aramid fiber was used, and the other components were the same as those in Example 3 of the present invention.

[0044] The specific component ratios of each example are as follows in the table:

[0045] Table 1 Component Ratio Table of Examples

[0046]

[0047]

[0048] Table 2 Antibacterial Performance Test Table

[0049] Bacterial species Bacteriostatic rate of Example 1 Bacteriostatic rate of Comparative Example 1 Escherichia coli 99.98％ 0％ Staphylococcus aureus 99.85％ 0％

[0050] Table 3 Barrier Performance Test

[0051] <![CDATA[Oxygen transmission rate (cm 3 / m 2 ·24h·0.1MPa)]]> <![CDATA[Water vapor transmission rate (g / m 2 ·24h)]]> Example 2 0.025 0.003 Comparative Example 2 0.35 0.85

[0052] Table 4 Mechanical Property Test Table

[0053] Tensile strength (Mpa) Tear strength (N / mm) Example 3 50 250 Comparative Example 3 40 120

[0054] Based on the above, the advantages of the present invention are as follows: The present invention uses a bisquaternary ammonium salt as an antibacterial additive and incorporates it into the PVC material, thereby endowing the modified PVC material with excellent antibacterial properties. The bisquaternary ammonium salt, with its broad-spectrum antibacterial property, can efficiently kill or significantly inhibit the growth of a variety of bacteria, fungi, and viruses. Its strong antibacterial activity stems from its unique cationic nature. These cations strongly interact with the negative charges on the microbial cell membrane, leading to the disintegration of the cell membrane and the demise of the microorganisms. This process is not only rapid and effective but also brings about durable and stable antibacterial performance to the modified PVC material, making this material show great application potential in the field of medical packaging. To further improve the comprehensive performance of the material, the present invention also adopts a multi-layer co-extrusion technology and adds an EVOH layer to the PVC material to form a composite PVC packaging material. As a high-performance barrier material, the excellent barrier performance of EVOH provides reliable protection for medical devices or drugs inside the packaging. During storage and transportation, it can effectively prevent the adverse effects of environmental factors such as oxygen and humidity on the items inside the packaging, ensuring the stability and safety of the items. In addition, the present invention also creatively introduces aramid fiber as a reinforcing fiber to be compounded with the PVC resin. Aramid fiber is known for its high strength, high modulus, and excellent chemical corrosion resistance. Its addition significantly improves the mechanical properties of the composite material, especially the tear resistance is greatly improved, making the PVC material show more tough and durable characteristics when facing various external force impacts. This improvement not only enhances the overall strength of the packaging material but also provides more comprehensive and reliable protection for the items inside the packaging, ensuring their safety and stability in complex environments. Dioctyl adipate is used as a plasticizer to lower the glass transition temperature of the PVC resin, making it softer and easier to process. At the same time, it can also improve the flexibility and ductility of PVC products, improving their hand feeling and use performance; aramid fiber is used as a reinforcing fiber to be compounded with the PVC resin, which can form a composite material with excellent mechanical properties and significantly improve the tear resistance; dilauryl thiodipropionate is used as an antioxidant to prevent the PVC resin from degrading due to oxidation during processing, storage, and use, thereby maintaining the physical properties, chemical stability, and extending the service life of the material. ACR can promote the plasticization process of PVC, lower the plasticization temperature, shorten the plasticization time, improve production efficiency, and improve the fluidity of the PVC melt, making the processing process smoother.

[0055] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A modified PVC for medical packaging, the formulation comprising: PVC resin powder, MBS, ACR, external lubricant, internal lubricant, methyltin stabilizer, bisquaternary ammonium salt, EVOH, dilauryl thiodipropionate, dioctyl adipate and aramid fiber, characterized in that: the mass percentages of the respective components are: 50% - 70% of PVC resin powder, 5% - 15% of MBS, 0.5% - 2% of ACR, 0.2% - 1% of external lubricant, 0.2% - 1% of internal lubricant, 1% - 3% of methyltin stabilizer, 2% - 5% of bisquaternary ammonium salt, 5% - 20% of EVOH, 0.1% - 1% of dilauryl thiodipropionate, 5% - 15% of dioctyl adipate and 1% - 5% of aramid fiber.

2. The modified PVC for medical packaging according to claim 1, characterized in that: The mass percentages of the respective components are: 50% of PVC resin powder, 10% of MBS, 1% of ACR, 1% of external lubricant, 1% of internal lubricant, 2% of methyltin stabilizer, 3% of bisquaternary ammonium salt, 20% of EVOH, 1% of dilauryl thiodipropionate, 8% of dioctyl adipate and 3% of aramid fiber.

3. A modified PVC for medical packaging according to claim 1, characterized in that: The mass percentages of the respective components are: 60% of PVC resin powder, 5% of MBS, 0.5% of ACR, 1% of external lubricant, 0.5% of internal lubricant, 1% of methyltin stabilizer, 2% of bisquaternary ammonium salt, 13% of EVOH, 1% of dilauryl thiodipropionate, 15% of dioctyl adipate and 1% of aramid fiber.

4. A modified PVC for medical packaging according to claim 1, characterized in that: The 65% of PVC resin powder, 5% of MBS, 1% of ACR, 0.5% of external lubricant, 1% of internal lubricant, 3% of methyltin stabilizer, 5% of bisquaternary ammonium salt, 5% of EVOH, 0.5% of dilauryl thiodipropionate, 10% of dioctyl adipate and 4% of aramid fiber.

5. The modified PVC for medical packaging according to claim 4, characterized in that: The external lubricant is specifically one of calcium stearate and zinc stearate, and the internal lubricant is one of polyethylene wax and oxidized polyethylene wax.

6. A preparation method of modified pvc for medical packaging, including Step 1, material preparation; Step 2, bisquaternary ammonium salt preparation; Step 3, mixing and pretreatment; Step 4, multi-layer co-extrusion calendaring; Step 5, forming and curing; Step 6, inspection and packaging; characterized in that: In Step 1 above, prepare the raw materials required for preparing modified PVC; In Step 2 above, prepare the bisquaternary ammonium salt raw materials required for production; In Step 3 above, mix the raw materials except EVOH according to the ratio to ensure uniform distribution of each component, and preheat the mixture; In Step 4 above, use multi-layer co-extrusion calendaring technology to add an EVOH layer to the middle layer of PVC; In Step 5 above, form the required packaging shape through the forming process and carry out the curing treatment; In Step 6 above, strictly inspect the prepared medical packaging materials, including appearance inspection and performance testing, to ensure that they meet the relevant standards and requirements.

7. The preparation method of a modified PVC for medical packaging according to claim 6, characterized in that: In Step 2 above, prepare long-chain alkylamine as the main reactant, select chloroalkane for quaternization reaction with long-chain alkylamine, select acetone as the solvent, and potassium hydroxide as the catalyst.

8. The preparation method of a modified PVC for medical packaging according to claim 7, characterized in that: In the second step, long-chain alkylamine and halogenated hydrocarbon are added to a reaction vessel in a certain proportion, and stirred at an appropriate temperature for a period of time to allow the quaternization reaction to proceed fully. During the reaction, the temperature, pressure and stirring speed are controlled. After the reaction is completed, an appropriate amount of hydrochloric acid is added to neutralize the excessive base, and the reaction product is washed with water to remove impurities such as unreacted raw materials, solvents and generated salts.

9. The preparation method of a modified PVC for medical packaging according to claim 8, characterized in that: In the second step, the washed product is dried to remove residual moisture. Through concentration operation, the concentration of the product is increased to facilitate subsequent separation and purification. The crystallization separation method is selected to further purify the separated product to improve its purity, and a bisquaternary ammonium salt is obtained.

10. The preparation method of a modified PVC for medical packaging according to claim 6, characterized in that: In the fourth step, the PVC raw material and the EVOH raw material are fed into a multi-layer co-extrusion extruder. After being heated and melted, they are extruded through the runner of the die. The PVC layer and the EVOH layer can be tightly combined at the die outlet, so that the EVOH layer is coated in the middle of the PVC layer. The extruded multi-layer composite material quickly passes through a cooling water tank to reduce the temperature and fix the shape.

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