A low-shrinkage polyvinyl chloride blood bag composition and preparation method thereof

Abstract

The present invention provides a low-shrinkage polyvinyl chloride blood bag composition and its preparation method, belonging to the technical field of polymer medical materials. The low-shrinkage polyvinyl chloride blood bag composition comprises, by weight, 100 parts of PVC resin; 1-2 parts of calcium-zinc stabilizer; 1-2 parts of auxiliary stabilizer; 45-60 parts of environmentally friendly plasticizer; 3-5 parts of rigidity enhancer; 10-20 parts of flexibility toughening agent; 0.5-1 part of ultraviolet light stabilizer; 0.3-0.8 parts of antibacterial agent; and 0.5-1 part of lubricant. The present invention also provides a method for preparing the low-shrinkage polyvinyl chloride blood bag composition. This composition significantly reduces shrinkage while simultaneously improving toughness and flexibility without compromising strength.

Description

Technical Field

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

[0002] Blood bags are the most common medical equipment and are widely used in clinical practice. Their main raw material 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. Regarding the shrinkage problem, there are also relevant patent applications, 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 (a copolymer of ultra-high molecular weight styrene and acrylonitrile and a terpolymer of methyl methacrylate, butadiene and styrene) to the ingredients to reduce the shrinkage of the film material. However, the copolymer of ultra-high molecular weight styrene and acrylonitrile has poor toughness, which will have some adverse effects on product performance. Summary of the Invention

[0003] The purpose of the present invention is to provide a low-shrinkage polyvinyl chloride blood bag composition and a preparation method thereof, which 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; UV stabilizer: 0.5-1 part; antibacterial agent: 0.3-0.8 part; lubricant: 0.5-1 part.

[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 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 the solvent and set aside;

[0015] Step 2: Dissolve the flexible toughening agent in a solvent and set aside;

[0016] Step 3: Weigh polyvinyl chloride, calcium zinc stabilizer, auxiliary stabilizer, ultraviolet light stabilizer, antibacterial agent, and lubricant in proportion, add them together 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 mixture obtained in step 3 into a twin-screw extruder for extrusion and granulation, and then cooling and granulating to obtain a low-shrinkage polyvinyl chloride blood bag composition.

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

[0019] Beneficial effects of the present 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 a vinyl chloride-acrylate-vinyl acetate copolymer resin; the polymethyl methacrylate and vinyl chloride-acrylate-vinyl acetate copolymer are mixed together with a plasticizer in the form of a resin solution at high temperature and are fully absorbed by the polyvinyl chloride resin. 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 while the toughness of the composition is improved, its strength will not be reduced due to the addition of the plasticizer; the vinyl chloride-acrylate-vinyl acetate copolymer solution Due to 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 interior of the resin particles as the center point, thereby increasing the friction between the molecular chains and promoting the plasticizing properties of the resin. The two have good synergistic effects. Under the synergistic effects 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 in the toughness of the composition is beneficial to the low-temperature storage of blood bags. The addition of the antibacterial agent makes the blood bags produced by the composition have a certain antibacterial effect. In this way, during the product disinfection process, the blood bags are 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; UV stabilizer: 0.5-1 part; antibacterial agent: 0.3-0.8 parts; lubricant: 0.5-1 part. 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; UV 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-based resin with a degree of polymerization of 2000-2500, wherein the resin has a plasticizer absorption capacity of ≥30g / 100g of resin, and the resin particles are required to have a high internal porosity. High plasticizer absorption and internal porosity facilitate 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 acetylated citrate is 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 the role of 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 contains 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 parahydroxybenzoate, 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 together into a mixer, then add an environmentally friendly plasticizer and the mixed solution of steps 1 and 2, and stir to obtain a mixed material; the stirring is preferably performed at high speed first, preferably at a stirring speed of 1500-2000 rpm, and when the temperature of the mixed material reaches 100° C., low-speed stirring is performed, preferably at a stirring speed of 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 discharged;

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

[0037] The rigidity enhancer polymethyl methacrylate and the flexible toughening agent vinyl chloride-acrylate-vinyl acetate copolymer in the present invention are mixed together with the plasticizer in the form of resin solution at high temperature and are fully absorbed by the polyvinyl chloride resin. 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 improves its toughness while not reducing its strength due to the addition of the plasticizer. The vinyl chloride-acrylate-vinyl acetate copolymer solution is The effect of ethylene is that 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 interior of the resin particles as the center point, thereby increasing the friction between the molecular chains and promoting the plasticizing properties of the resin. The two have good synergistic effect. 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 the blood bag.

[0038] The present invention will be further described below with reference to the following examples, but the present invention is not limited thereto. Table 1 is an example of the present invention, and Table 2 is a 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 in a weight ratio of polymethyl methacrylate to acetone of 35:65, and setting aside;

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

[0045] (3) According to the proportions in Table 1, a mixture of polyvinyl chloride, calcium stearate and zinc stearate (wherein the mass ratio of calcium stearate to zinc stearate is preferably 2:1), phosphite, LA-68, butyl parahydroxybenzoate and methyl silicone oil are weighed and added to a mixer. Then, acetyl tributyl citrate and the mixed solution of step (1) and step (2) are added. The mixture is first stirred at a high speed of 1500 rpm. When the temperature of the mixture reaches 100°C, the mixture is stirred at a low speed of 800 rpm until the acetone in the material is completely volatilized. When the temperature of the mixture reaches 110±5°C, the material is discharged.

[0046] (4) The mixed materials are fed into a twin-screw extruder for extrusion and 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 thick were cut out. Then, sheets were pressed into 2 mm sheets in a press at 180°C, and standard specimens were punched out to test their performance.

[0048] Examples 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 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 Flexible toughening agent 10 12 15 15 18 20 UV stabilizers 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 lubricant 0.5 0.6 0.7 0.8 0.9 1.0

[0052] Comparative Example 1

[0053] The formulation and preparation process of Comparative Example 1 were the same as those of Example 3, except that the rigidity enhancer in Comparative Example 1 was in a non-solution form (i.e., a rigid resin), and step (1) was omitted from the preparation process. The rigid resin was added during the mixing step. The raw material ratios are shown in Table 2.

[0054] Comparative Example 2

[0055] The formulation and preparation process of Comparative Example 2 were the same as those of Example 3, except that the flexible toughening agent in Comparative Example 2 was in a non-solution form (i.e., a flexible resin), and step (2) was omitted from the preparation process. The flexible resin was added during the mixing step. The raw material ratios are 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 proportions of the raw materials are 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 proportions of the raw materials are 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 MBS (methyl methacrylate-styrene-butadiene copolymer) is used as a toughening agent in Comparative Example 5, and no rigidity enhancer and flexibility toughening agent are used; steps (1) and (2) are omitted in the preparation process; and the proportions of the raw materials are shown in Table 2.

[0062] Comparative Example 6

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

[0064] Comparative Example 7

[0065] The formulation 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 28 g / 100 g 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 - - - - - - Flexible toughening agent 15 - 15 - - 15 15 Flexible resin - 15 - - - - - UV stabilizers 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 lubricant 0.7 0.7 0.7 0.7 0.7 0.7 0.7 MBS resin - - - - 20 - -

[0068] The performance test results of the embodiment of the present invention are shown in Table 3, and the performance test results of the comparative example 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 specimen 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 a rectangular sample before and after UV irradiation and sterilization at 121°C for 30 minutes to the original size.

[0075] From the test results of the embodiments and comparative examples, it can be seen that since 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 in comparative example 1 and an increase in shrinkage in 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 instead of 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 has a significant effect on the shrinkage, but is not added in comparative example 6, resulting in an increase in shrinkage; 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 ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents 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: Calculated by mass, including: 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; UV stabilizer: 0.5-1 part; antibacterial agent: 0.3-0.8 part; lubricant: 0.5-1 part; The rigidity enhancer is polymethyl methacrylate; The flexible toughening agent is vinyl chloride-acrylate-vinyl acetate copolymer resin.

2. The 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 ultraviolet light stabilizer is LA-68.

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

7. 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 the solvent and set aside; Step 2: Dissolve the flexible toughening agent in a solvent and set aside; Step 3: Weigh polyvinyl chloride, calcium zinc stabilizer, auxiliary stabilizer, ultraviolet light stabilizer, antibacterial agent, and lubricant in proportion, add them together 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 mixture obtained in step 3 into a twin-screw extruder for extrusion and granulation, and then cooling and granulating to obtain a low-shrinkage polyvinyl chloride blood bag composition.

8. The method for preparing a low-shrinkage polyvinyl chloride blood bag composition according to claim 7, characterized in that: The solvent in step 1 and step 2 is acetone.

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