Low-shrinkage polyvinyl chloride blood bag composition and preparation method thereof

Abstract

The invention provides a low-shrinkage polyvinyl chloride blood bag composition and a preparation method thereof, and belongs to the technical field of polymer medical materials. The low-shrinkage polyvinyl chloride (PVC) blood bag composition comprises the following components in parts by mass: 100 parts of PVC resin; 1-2 parts of a calcium-zinc stabilizer; 1-2 parts of an auxiliary stabilizer; 45-60 parts of an environment-friendly plasticizer; 3-5 parts of a rigid reinforcing agent; 10 to 20 parts of a flexible toughening agent; 0.5 to 1 part of an ultraviolet light stabilizer; 0.3 to 0.8 part of an antibacterial agent; and 0.5-1 part of a lubricant. The invention further provides a preparation method of the low-shrinkage polyvinyl chloride blood bag composition. According to the composition, the shrinkage rate is greatly reduced, meanwhile, the toughness and the flexibility of the composition are improved, and the strength of the composition is not reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer medical materials, and in particular relates to a low-shrinkage polyvinyl chloride blood bag composition and a preparation method thereof. Background Art

[0002] As the most common medical device, blood bags are widely used in clinical practice. The main raw material for their production is polyvinyl chloride. Blood bags are required to have good toughness, softness, strength and low shrinkage. However, blood bags made of polyvinyl chloride will shrink significantly during high-temperature disinfection and sterilization, which will cause changes in the design capacity and film thickness of the blood bags, thereby affecting the quality and even safety of the product. There are also relevant patent applications for the shrinkage problem, such as the application number 201811371905.4, a low-shrinkage medical PVC blood bag film material and its preparation method, which is achieved by improving the formula and adding an anti-shrinkage agent (copolymer of ultra-high molecular weight styrene and acrylonitrile and terpolymer of methyl methacrylate, butadiene and styrene) to the ingredients to reduce the shrinkage of the film material. However, the copolymers of ultra-high molecular weight styrene and acrylonitrile have poor toughness, which will have some adverse effects on product performance. Summary of the invention

[0003] The object of the present invention is to provide a low-shrinkage polyvinyl chloride blood bag composition and a preparation method thereof, wherein the composition significantly reduces the shrinkage rate while improving the toughness and softness of the composition without reducing the strength of the composition.

[0004] The present invention first provides a low-shrinkage polyvinyl chloride blood bag composition, which comprises, by weight:

[0005] PVC resin: 100 parts; calcium zinc stabilizer: 1-2 parts; auxiliary stabilizer: 1-2 parts; environmentally friendly plasticizer: 45-60 parts; rigidity enhancer: 3-5 parts; flexible toughening agent: 10-20 parts; ultraviolet light stabilizer: 0.5-1 parts; antibacterial agent: 0.3-0.8 parts; lubricant: 0.5-1 parts.

[0006] Preferably, the calcium zinc stabilizer is a mixture of calcium stearate and zinc stearate, wherein the mass ratio of calcium stearate to zinc stearate is 2:1.

[0007] Preferably, the auxiliary stabilizer is a phosphite.

[0008] Preferably, the environmentally friendly plasticizer is acetyl tributyl citrate.

[0009] Preferably, the rigidity enhancer is polymethyl methacrylate.

[0010] Preferably, the flexible toughening agent is vinyl chloride-acrylate-vinyl acetate copolymer resin.

[0011] Preferably, the ultraviolet light stabilizer is LA-68.

[0012] Preferably, the antibacterial agent is butyl paraben; and the lubricant is methyl silicone oil.

[0013] The present invention also provides a method for preparing a low-shrinkage polyvinyl chloride blood bag composition, comprising:

[0014] Step 1: Dissolve the rigidity enhancer in a solvent and set aside;

[0015] Step 2: dissolving the flexible toughening agent in a solvent for later use;

[0016] Step 3: Weigh polyvinyl chloride, calcium zinc stabilizer, auxiliary stabilizer, ultraviolet light stabilizer, antibacterial agent, and lubricant according to proportion, add them into a mixer, then add environmentally friendly plasticizer and the mixed solution of step 1 and step 2, stir, and obtain a mixed material;

[0017] Step 4: feeding the mixed material in step 3 into a twin-screw extruder for extrusion and granulation, and obtaining a low-shrinkage polyvinyl chloride blood bag composition through cooling and pelletizing.

[0018] Preferably, the solvent in step 1 and step 2 is acetone.

[0019] Beneficial Effects of the Invention

[0020] The present invention provides a low-shrinkage polyvinyl chloride blood bag composition and a preparation method thereof. In the composition, the rigidity enhancer is polymethyl methacrylate, and the flexible toughening agent is vinyl chloride-acrylate-vinyl acetate copolymer resin; the copolymer of polymethyl methacrylate and vinyl chloride-acrylate-vinyl acetate is fully absorbed by the polyvinyl chloride resin through high-temperature mixing together with a plasticizer in the form of a resin solution; due to the high porosity of the resin and the high plasticizer absorption rate, the resin solution and the plasticizer enter the internal pores of the PVC resin particles together; during the processing of the composition, the polymethyl methacrylate plays a role in toughening the rigid particles, so that the composition improves its toughness while not reducing its strength due to the addition of the plasticizer; the vinyl chloride-acrylate-vinyl acetate copolymer solution Because of the effect of vinyl chloride, it has excellent compatibility with polyvinyl chloride resin and does not precipitate inside the resin particles. Due to the effect of the flexible chain segments of acrylate, it is entangled with the polyvinyl chloride molecules, forming an interpenetrating cross-linked network structure with the inside of the resin particles as the center point, which improves the friction between the molecular chains and promotes the plasticization performance of the resin. The two have good synergistic effects. Under the synergistic effect of the rigidity enhancer and the flexible toughening agent, the shrinkage rate of the composition is greatly reduced during the ultraviolet high-temperature disinfection process, and the toughness of the composition is improved without reducing the strength of the composition. The improvement of the toughness of the composition is beneficial to the low-temperature storage of blood bags; the addition of the antibacterial agent makes the blood bag produced by the composition itself have a certain antibacterial effect, so that during the product disinfection process, the blood bag is more hygienic and the disinfection is more thorough. DETAILED DESCRIPTION

[0021] The present invention first provides a low-shrinkage polyvinyl chloride blood bag composition, which comprises, by weight:

[0022] PVC resin: 100 parts; calcium zinc stabilizer: 1-2 parts; auxiliary stabilizer: 1-2 parts; environmentally friendly plasticizer: 45-60 parts; rigidity enhancer: 3-5 parts; flexible toughening agent: 10-20 parts; ultraviolet light stabilizer: 0.5-1 parts; antibacterial agent: 0.3-0.8 parts; lubricant: 0.5-1 parts. Preferably: PVC resin: 100 parts; calcium zinc stabilizer: 1.5-1.8 parts; auxiliary stabilizer: 1.3-1.8 parts; environmentally friendly plasticizer: 50-55 parts; rigidity enhancer: 4-5 parts; flexible toughening agent: 12-15 parts; ultraviolet light stabilizer: 0.7-0.9 parts; antibacterial agent: 0.5-0.7 parts; lubricant: 0.6-0.8 parts.

[0023] According to the present invention, the PVC resin is preferably an ethylene resin with a polymerization degree of 2000-2500, wherein the plasticizer absorption of the resin is ≥30g / 100g of resin, and the internal porosity of the resin particles is required to be high. The higher plasticizer absorption and internal porosity of the particles are conducive to the uniform and rapid absorption of plasticizers and other additives into the internal voids of the resin particles.

[0024] According to the present invention, the calcium zinc stabilizer is preferably a mixture of calcium stearate and zinc stearate, wherein the mass ratio of calcium stearate to zinc stearate is preferably 2:1.

[0025] According to the present invention, the auxiliary stabilizer is preferably a phosphite.

[0026] According to the present invention, the environmentally friendly plasticizer is preferably acetyl tributyl citrate, because the acetylation of the citrate ester makes it more firmly bonded to the polyvinyl chloride resin and is not easily washed out.

[0027] According to the present invention, the rigidity enhancer is preferably polymethyl methacrylate, which plays a role in toughening the rigid particles inside the resin.

[0028] According to the present invention, the flexible toughening agent is preferably vinyl chloride-acrylate-vinyl acetate copolymer resin, because it has vinyl chloride groups and is very tightly combined with polyvinyl chloride resin.

[0029] According to the present invention, the ultraviolet light stabilizer is preferably LA-68.

[0030] According to the present invention, the antibacterial agent is preferably butyl p-hydroxybenzoate, which is a hygienic and environmentally friendly additive.

[0031] According to the present invention, the lubricant is preferably methyl silicone oil.

[0032] The present invention also provides a method for preparing a low-shrinkage polyvinyl chloride blood bag composition, comprising:

[0033] Step 1: dissolving the rigidity enhancer in a solvent for later use; the solvent is preferably acetone; the weight ratio of the rigidity enhancer to the solvent is preferably (30-40): (60-70);

[0034] Step 2: dissolving the flexible toughening agent in a solvent for later use; the solvent is preferably acetone; the weight ratio of the flexible toughening agent to the solvent is preferably (25-35): (65-75);

[0035] Step 3: Weigh polyvinyl chloride, calcium zinc stabilizer, auxiliary stabilizer, ultraviolet light stabilizer, antibacterial agent, and lubricant in proportion, add them into a mixer together, then add environmentally friendly plasticizer and the mixed solution of step 1 and step 2, stir to obtain a mixed material; the stirring is preferably high-speed stirring first, the stirring speed is preferably 1500-2000 rpm, when the temperature of the mixed material reaches 100°C, low-speed stirring is performed, the stirring speed is preferably 700-1000 rpm, until the solvent in the material is completely volatilized, and when the temperature of the mixed material reaches 110±5°C, the material is released;

[0036] Step 4: feeding the mixture of step 3 into a twin-screw extruder for extrusion granulation, the temperature of the twin-screw extruder is preferably 150°C to 160°C, the feed speed is preferably 15-25r / min, the main engine speed is preferably 85-100r / min, and the low shrinkage polyvinyl chloride blood bag composition is obtained after cooling and pelletizing.

[0037] The rigidity enhancer polymethyl methacrylate and the flexible toughening agent vinyl chloride-acrylate-vinyl acetate copolymer in the present invention are fully absorbed by the polyvinyl chloride resin through high-temperature mixing together with the plasticizer in the form of resin solution. Due to the high porosity of the resin and the high plasticizer absorption rate, the resin solution and the plasticizer enter the internal pores of the PVC resin particles. During the processing of the composition, the polymethyl methacrylate plays a role in toughening the rigid particles, so that the composition will not reduce its strength due to the addition of the plasticizer while improving its toughness. The vinyl chloride-acrylate-vinyl acetate copolymer solution is due to the high porosity of the resin and the high plasticizer absorption rate. The role of ethylene is that it has excellent compatibility with polyvinyl chloride resin and does not precipitate inside the resin particles. Due to the role of the flexible chain segments of acrylate, it is entangled with the polyvinyl chloride molecules, with the interior of the resin particles as the center point, to form an interpenetrating cross-linked network structure, which increases the friction between the molecular chains and promotes the plasticization performance of the resin. The two have good synergistic effects. Under the synergistic effect of the rigidity enhancer and the flexible toughening agent, during the ultraviolet high-temperature disinfection process, the shrinkage rate of the composition is greatly reduced, and the toughness of the composition is improved without reducing the strength of the composition. The improvement of the toughness of the composition is beneficial to the low-temperature storage of the blood bag.

[0038] The present invention is further described below in conjunction with the examples, but the present invention is not limited thereby. Table 1 is the examples of the present invention, and Table 2 is the comparative example.

[0039] The PVC in the embodiment is a product of Sinopec Qilu Branch, with an average degree of polymerization of 2250 and a plasticizer absorption rate of 32 g / 100 g resin.

[0040] The polymethyl methacrylate in the examples is a product of LG Corporation.

[0041] The vinyl chloride-acrylate-vinyl acetate copolymer in the examples is a product of Wuxi Honghui New Materials Co., Ltd.

[0042] Example 1

[0043] (1) dissolving polymethyl methacrylate in acetone, wherein the weight ratio of polymethyl methacrylate to acetone is 35:65, and setting aside;

[0044] (2) dissolving a copolymer of vinyl chloride-acrylate-vinyl acetate in acetone, wherein the weight ratio of the copolymer to acetone is 30:70, and setting aside;

[0045] (3) According to the proportions in Table 1, weigh polyvinyl chloride, a mixture of calcium stearate and zinc stearate (wherein the mass ratio of calcium stearate to zinc stearate is preferably 2:1), phosphite, LA-68, butyl p-hydroxybenzoate, and methyl silicone oil, add them together into a mixer, then add acetyl tributyl citrate and the mixed solution of step (1) and step (2), first stir at a high speed of 1500 rpm, and when the temperature of the mixed material reaches 100° C., stir at a low speed of 800 rpm until the acetone in the material is completely volatilized, and when the temperature of the mixed material reaches 110±5° C., discharge the material;

[0046] (4) The mixed materials are fed into a twin-screw extruder for extrusion granulation. The temperature of the twin-screw extruder is 150° C. to 160° C., the feed speed is 20 r / min, and the main engine speed is 85 r / min. After cooling and pelletizing, the composition of the present invention is obtained.

[0047] (5) The prepared particles were plasticized in a double roller at 160°C for 5 minutes, and sheets of about 2 mm thickness were cut out. Then, sheets of 2 mm thickness were pressed in a press at 180°C, and standard specimens were punched out and their performance was tested.

[0048] Embodiment 2-6

[0049] The preparation methods of Examples 2-6 are the same as those of Example 1, wherein the proportions of the raw materials are as shown in Table 1.

[0050] Table 1 Formula of Examples 1-6 of the present invention

[0051] project Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 PVC resin 100 100 100 100 100 100 Calcium zinc stabilizer 1.0 1.2 1.5 1.5 1.8 2.0 Auxiliary stabilizer 1.2 1.5 1.3 1.8 2.0 1.5 Environmentally friendly plasticizer 45 50 50 55 50 60 Rigidity enhancer 3.0 4.0 5.0 5.0 4.5 4.0 Flexibility enhancer 10 12 15 15 18 20 UV stabilizer 0.5 0.7 0.8 0.8 0.9 1.0 Antimicrobial agents 0.4 0.5 0.6 0.6 0.7 0.8 Lubricants 0.5 0.6 0.7 0.8 0.9 1.0

[0052] Comparative Example 1

[0053] The formula and preparation process of Comparative Example 1 are the same as those of Example 3, except that the rigidity enhancer in Comparative Example 1 is in a non-solution form (i.e., a rigid resin), step (1) is omitted in the preparation process, and the rigid resin is added in the mixing step. The proportion of the raw materials is shown in Table 2.

[0054] Comparative Example 2

[0055] The formula and preparation process of Comparative Example 2 are the same as those of Example 3, except that the flexible toughening agent in Comparative Example 2 is in a non-solution form (i.e., a flexible resin), step (2) is omitted in the preparation process, and the flexible resin is added in the mixing step. The proportion of the raw materials is shown in Table 2.

[0056] Comparative Example 3

[0057] The formula and preparation process of Comparative Example 3 are the same as those of Example 3, except that Comparative Example 3 only uses a flexible toughening agent without a rigidity enhancer, and step (1) is omitted in the preparation process; the proportion of the raw materials is shown in Table 2.

[0058] Comparative Example 4

[0059] The formula and preparation process of Comparative Example 4 are the same as those of Example 3, except that Comparative Example 4 only uses a rigidity enhancer without a flexible toughening agent, and step (2) is omitted in the preparation process; the proportion of the raw materials is shown in Table 2.

[0060] Comparative Example 5

[0061] The formula and preparation process of Comparative Example 5 are the same as those of Example 3, except that Comparative Example 5 uses MBS (methyl methacrylate-styrene-butadiene copolymer) as a toughening agent, without a rigidity enhancer and a flexible toughening agent; steps (1) and (2) are omitted in the preparation process; and the proportion of the raw materials is shown in Table 2.

[0062] Comparative Example 6

[0063] The formula and preparation process of Comparative Example 6 are the same as those of Example 3, except that no ultraviolet light stabilizer is added to Comparative Example 6, and the proportion of the raw materials is shown in Table 2.

[0064] Comparative Example 7

[0065] The formula and preparation process of Comparative Example 7 are the same as those of Example 3, except that the resin used in Comparative Example 7 has a polymerization degree of 2000, the plasticizer absorption amount is 28g / 100g of resin, and the raw material ratio is shown in Table 2.

[0066] Table 2 Comparative Examples 1-6 Formula

[0067] project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 PVC resin 100 100 100 100 100 100 - PVC(2000) - - - - - - 100 Calcium zinc stabilizer 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Auxiliary stabilizer 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Environmentally friendly plasticizer 50 50 50 50 50 50 50 Rigidity enhancer - 5.0 - 5.0 - 5.0 5.0 Rigid resin 5.0 - - - - - - Flexibility enhancer 15 - 15 - - 15 15 Flexible resin - 15 - - - - - UV stabilizer 0.8 0.8 0.8 0.8 0.8 - 0.8 Antimicrobial agents 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Lubricants 0.7 0.7 0.7 0.7 0.7 0.7 0.7 MBS resin - - - - 20 - -

[0068] The performance test results of the embodiments of the present invention are shown in Table 3, and the performance test results of the comparative examples are shown in Table 4:

[0069] Table 3 Performance test results of Examples 1-6 of the present invention

[0070]

[0071] Note: Tensile strength and elongation at break are tested in accordance with GB / T1040-2006. Shrinkage test method: The shrinkage is characterized by the percentage of the difference in size between a rectangular sample before and after UV irradiation and sterilization at 121°C for 30 minutes to the original size.

[0072] Table 4 Performance test results of comparative examples 1-6 of the present invention

[0073]

[0074] Note: Tensile strength and elongation at break are tested in accordance with GB / T1040-2006. Shrinkage test method: The shrinkage is characterized by the percentage of the difference in size between the rectangular sample before and after UV irradiation and 121°C, 30 minutes sterilization and the original size.

[0075] From the test results of the embodiments and comparative examples, it can be seen that because comparative examples 1 and 2 are directly added and mixed, they cannot enter the interior of the resin particles together with the plasticizer, resulting in a decrease in strength of comparative example 1 and an increase in shrinkage of comparative example 2; the results of comparative examples 3 and 4 show that the rigid reinforced resin and the flexible toughening resin in the present invention have a good synergistic effect, and the lack of either one will result in an increase in shrinkage; in comparative example 5, the toughening agent is directly added to replace the rigid and flexible resins of the present invention, resulting in a significant increase in shrinkage and a decrease in strength; the ultraviolet light stabilizer obviously has a certain effect on the shrinkage, but it is not added in comparative example 6, so the shrinkage increases; the change in the basic properties of the resin in comparative example 7 has a certain impact on the strength and shrinkage.

[0076] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A low shrinkage polyvinyl chloride blood bag composition, characterized in that: According to the mass percentage, it includes: PVC resin: 100 parts; calcium zinc stabilizer: 1-2 parts; auxiliary stabilizer: 1-2 parts; environmentally friendly plasticizer: 45-60 parts; rigidity enhancer: 3-5 parts; flexible toughening agent: 10-20 parts; ultraviolet light stabilizer: 0.5-1 parts; antibacterial agent: 0.3-0.8 parts; lubricant: 0.5-1 parts.

2. A low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The calcium zinc stabilizer is a mixture of calcium stearate and zinc stearate, wherein the mass ratio of calcium stearate to zinc stearate is 2:

1.

3. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The auxiliary stabilizer is phosphite.

4. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The environmentally friendly plasticizer is acetyl tributyl citrate.

5. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The rigidity enhancer is polymethyl methacrylate.

6. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The flexible toughening agent is vinyl chloride-acrylate-vinyl acetate copolymer resin.

7. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The ultraviolet light stabilizer is LA-68.

8. The low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: The antibacterial agent is butyl p-hydroxybenzoate; and the lubricant is methyl silicone oil.

9. The method for preparing a low shrinkage polyvinyl chloride blood bag composition according to claim 1, characterized in that: include: Step 1: Dissolve the rigidity enhancer in a solvent and set aside; Step 2: dissolving the flexible toughening agent in a solvent for later use; Step 3: Weigh polyvinyl chloride, calcium zinc stabilizer, auxiliary stabilizer, ultraviolet light stabilizer, antibacterial agent, and lubricant according to proportion, add them into a mixer, then add environmentally friendly plasticizer and the mixed solution of step 1 and step 2, stir, and obtain a mixed material; Step 4: feeding the mixed material in step 3 into a twin-screw extruder for extrusion and granulation, and obtaining a low-shrinkage polyvinyl chloride blood bag composition through cooling and pelletizing.

10. The method for preparing a low shrinkage polyvinyl chloride blood bag composition according to claim 9, characterized in that: The solvent in step 1 and step 2 is acetone.

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