CN117004137A - Radiation-resistant medical polypropylene for low-temperature centrifuge tubes and preparation method thereof - Google Patents

Abstract

A radiation-resistant medical polypropylene used for low-temperature centrifuge tubes. Its raw materials include polypropylene resin, polyolefin elastomer, composite nucleating agent and antioxidant. The mass parts of each raw material are: polypropylene resin: 75-95 parts, polyolefin elastomer: 5-25 parts, composite nucleating agent: 0.2-1.0 parts, antioxidant: 0.05-0.5 parts. The invention uses polyolefin elastomer OBC, composite nucleating agent and antioxidant to synergize with each other in the formula, and the obtained polypropylene has low temperature resistance, radiation resistance and high transparency performance.

Description

Radiation-resistant medical polypropylene for low-temperature centrifuge tubes and preparation method thereof

Technical field

The invention belongs to the technical field of polymer materials, and specifically relates to a radiation-resistant medical polypropylene used in low-temperature centrifuge tubes and a preparation method thereof.

Background technique

Polypropylene (PP) is a thermoplastic resin made from the polymerization of propylene. It is currently one of the most widely used synthetic resins at home and abroad and has the fastest growing output. It has wide sources, is light and cheap, non-toxic and tasteless, and has high strength. It has the advantages of high thermal stability and good chemical stability, and has a wide range of applications in various fields. Especially in the medical field, in terms of disposable medical devices such as disposable syringes, blood transfusions, infusion tubes, etc., there are corresponding polypropylene products and the "YY/T0242-2007 Medical Grade Polypropylene Safety Standard", while abroad it has been widely used It is used in packaging materials, laboratory equipment, high-end medical equipment and other fields. The research and development of medical polypropylene materials will also become one of the hot spots in the field of medical materials in recent years.

As a raw material for the synthesis of some medical products, polypropylene needs to be effectively sterilized before use. The most common sterilization methods are high-temperature sterilization and ethylene oxide sterilization (EO) for effective sterilization, but at the same time, the disadvantages are also extremely obvious. At the same time, the method of irradiation sterilization has gradually attracted people's attention, using high-energy rays generated by electric radiation such as gamma rays, X-rays, and electron beams to achieve sterilization purposes.

Medical products require a certain degree of transparency when used. When preparing some highly transparent medical products that are resistant to low temperature and radiation, often while the performance reaches the standard, the transparency of the product will decrease, and the radiation sterilization process will also cause Turns yellow and reduces transparency. Among the existing patents, some research has been done on the low-temperature resistance, radiation resistance, and high transparency of polypropylene. For example, patent publication numbers CN109265826A, CN112812426A, and CN111675856B respectively explore the relationship between low-temperature resistance and transparency. The relationship between radioactivity and transparency, but there is no medical polypropylene material that is both low-temperature and radiation-resistant and has high transparency.

Contents of the invention

In view of the above-mentioned opaque defects caused by low-temperature resistance and radiation resistance, the present invention provides a method for preparing low-temperature centrifuge tubes and radiation-resistant medical polypropylene by adding block OBC, composite nucleating agent and Combination of antioxidants to achieve the preparation of radiation-resistant medical polypropylene for cryogenic centrifuge tubes.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A radiation-resistant medical polypropylene used for low-temperature centrifuge tubes. Its raw materials include polypropylene resin, polyolefin elastomer, composite nucleating agent and antioxidant. The mass parts of each raw material are:

Polypropylene resin: 75-95 parts

Polyolefin elastomer: 5-25 parts

Composite nucleating agent: 0.2-1.0 parts

Antioxidants: 0.05-0.5 parts.

According to the present invention, the selected polypropylene is any one or more of copolymerized polypropylene (PPR or PPB) and homopolymerized polypropylene (PPH), and the melt flow index of the polypropylene is in the range of 10-30g/10min.

According to the present invention, the selected polyolefin elastomer is one or more of OBC-9507, OBC-9100, and OBC-9500. It is preferred to use OBC-9507 and OBC-9500 in combination with a compound ratio of 1:1.

According to the present invention, the nucleating agent selected is a composite nucleating agent which is a compound combination of an α nucleating agent and a β nucleating agent. Preferably, the α nucleating agent is selected from DMDBS (1,3:2,4- Bis(3,4-dimethylbenzylidene)sorbitol), NA-11(sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate), NA-21( 2,2-Methylenebis(4,6-di-n-butylphenol)sodium phosphate), NX8000 (bis-1,3,2,4(4'-propylbenzylidene)1-propylsorbitol , the beta nucleating agent is selected from NU-100 (N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide), DCHT (dicyclohexylterephthalamide), TPDT (triphenyldithiazine) , any one or more of HPN-68 (bicyclo[2.2.1]heptanedicarboxylic acid sodium salt).

According to the present invention, the proportion of the two composite nucleating agents is selected. Preferably, the mass ratio is 1:1~5:1.

According to the present invention, the selected antioxidant is a combination of a main antioxidant and an auxiliary antioxidant. The main antioxidant is selected from the antioxidant 1098 (N,N'-bis-(3-(3,5-ditert. Butyl-4-hydroxyphenyl)propionyl)hexanediamine), antioxidant 1010 (tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester), antioxidant Oxygen 1076 (β-(3,5-di-tert-butyl-4-hydroxyphenyl)octadecylpropionate), antioxidant 702 (4,4'-methylenebis(2,6-di Any one or more of tert-butylphenol)); the auxiliary antioxidant is selected from the antioxidant DSTP (distearyl thiodipropionate), antioxidant 168 (tri(2,4-di-tert. Butyl)phenyl phosphite), antioxidant 9228 (bis(2,4-dicumylphenyl)pentaerythritol-diphosphite), antioxidant 300[4, 4'-thiobis(6- tert-butyl-3-methylphenol)] any one or more.

According to the present invention, the mass ratio of the main antioxidant and the auxiliary antioxidant is preferably 1:1 to 1:3. It is preferred that the total content of primary antioxidant and auxiliary antioxidant is 0.1 to 0.2 parts.

According to the present invention, the low-temperature-resistant, radiation-resistant and highly transparent medical polypropylene can be used in products such as medical cryopreservation tubes and medical centrifuge tubes.

According to the present invention, after being irradiated by 25kGy high-energy rays, the product can still be used at temperatures of -20 to -196°C, and has excellent low-temperature radiation resistance and high transparency.

Compared with the prior art, the beneficial effects of the present invention are:

The invention uses polyolefin elastomer OBC, composite nucleating agent and antioxidant to synergize with each other in the formula, and the obtained polypropylene has low temperature resistance, radiation resistance and high transparency performance. Through the addition of polyolefin elastomer OBC, the composite nucleating agent is promoted to introduce more nucleation sites into the PP matrix to form smaller grains, which accelerates nucleation and crystallization while forming smaller spherulites. Dimensional polymerization, the polypropylene material formed by this is more conducive to the transmission of light and has higher transparency. It solves the problem of preparing highly transparent medical polypropylene materials while maintaining both low temperature resistance and radiation resistance.

Implementation

The substantive content of the present invention will be further explained below through specific examples.

Examples 1~19

Add polypropylene resin, polyolefin elastomer, composite nucleating agent, and antioxidant to a high-speed mixer in a certain proportion and mix evenly to obtain a mixture. Add the mixture to the main hopper of the twin-screw extruder. Extrusion granulation and processing using a single-screw injection molding machine to obtain a radiation-resistant medical polypropylene product for low-temperature centrifuge tubes. Extrusion and injection molding temperatures are 160~210℃.

The above products were irradiated with a 5MeV electron accelerator at a dose of 25kGy, and tested after the irradiation was completed. The test method is national standard.

The composition of raw materials is expressed in parts by mass, as shown in Table 1:

Table 1

Component/Model Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Polypropylene/PPR 85 85 85 85 85 85 85 85 85 85 85 85 75 80 90 95 85 85 85 85 85 85 85 OBC/9507 — 15 15 — 15 — — — — — — — — — — — 7.5 — — — — — — OBC/9100 — — — — — 15 — 15 15 15 15 15 25 20 10 5 — 15 15 15 15 15 15 OBC/9500 — — — — — — 15 — — — — — — — — — 7.5 — — — — — — POE/8150 — — — 15 — — — — — — — — — — — — — — — — — — — Alpha nucleating agent/DMDBS 0.3 0.3 — 0.3 0.3 0.3 0.3 — — — — — — — — — — — — — — — — Alpha nucleating agent/NA-21 — — — — — — — 0.3 — 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Alpha nucleating agent/NX-8000 — — — — — — — — 0.3 — — — — — — — — — — — — — — Beta nucleating agent/NU-100 0.3 — 0.3 0.3 0.3 0.3 0.3 — — — — — — — — — — — — — — — — Beta nucleating agent/DCHT — — — — — — — 0.3 — 0.2 0.1 0.6 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Beta nucleating agent/TPDT — — — — — — — — 0.3 — — — — — — — — — — — — — — Main antioxidant/1010 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 — — 0.1 0.1 0.2 0.2 Main antioxidant/702 — — — — — — — — — — — — — — — — — 0.1 — — — — — Main antioxidant/1098 — — — — — — — — — — — — — — — — — — 0.1 — — — — auxiliary antioxidant/DSTP 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 — 0.1 0.05 Auxiliary antioxidant/9228 — — — — — — — — — — — — — — — — — — — 0.05 0.05 — — Auxiliary antioxidant/168 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 — 0.05 0.1 0.05

The raw material composition of Comparative Example 1 is the same as that of Example 1, except that the polyolefin elastomer OBC is not added; the preparation method of Comparative Example 1 is exactly the same as that of Example 1.

The raw material composition of Comparative Example 2 is the same as that of Example 1, except that no beta nucleating agent is added; the preparation method of Comparative Example 1 is exactly the same as that of Example 1.

The raw material composition of Comparative Example 3 is the same as that of Example 1, except that no alpha nucleating agent is added; the preparation method of Comparative Example 1 is exactly the same as that of Example 1.

The raw material composition of Comparative Example 4 is the same as that of Example 1, except that the polyolefin elastomer OBC is not added and other types of POE are added; the preparation method of Comparative Example 1 is exactly the same as that of Example 1.

The products prepared in the above examples and comparative examples were tested, and the test results are listed in Table 2.

Table 2

Test items Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Haze (%) 19.3 22.6 25.2 30.3 18.1 13.2 16.8 12.8 14.8 8.6 12.3 15.2 16.8 13.2 13.1 14.1 8.1 11.9 12.3 13.2 14.6 14.3 14.1 yellowness index 1.13 1.09 1.13 1.01 1.03 1.12 1.03 0.95 1.02 0.86 1.02 1.03 1.06 1.12 1.06 1.07 0.80 0.95 1.02 1.25 1.21 1.62 1.55 -40℃ simply supported beam impact strength gap (kJ/m2) 7.5 16.1 15.1 27.4 19.2 19.5 18.2 21.9 20.5 26.8 20.1 18.7 20.5 23.2 21.2 15.2 27.5 22.3 21.4 21.3 22.9 22.5 22.6

According to the results in Table 2, it can be seen from Examples 1 to 19 that the formula provided by the present invention has better low temperature resistance and radiation resistance, and also has high transparency performance.

Comparing Comparative Example 1 and Example 1, it can be seen that without adding the polyolefin elastomer OBC, the impact strength is significantly lower than that with the added polyolefin elastomer OBC. In addition, the addition of OBC refines the spherulite molecules and increases the light transmittance. .

Comparing Comparative Example 2 and Example 1, it can be seen that the haze of the material without adding β nucleating agent has increased. This is because the addition of β nucleating agent causes the matrix to form dendritic β crystals and its chain flexibility also becomes better. , the size of the spherulites also becomes smaller, which is beneficial to improving the light transmittance and low temperature resistance.

Comparing Comparative Example 3 and Example 1, it can be seen that the haze and yellowness index of the material without the addition of α-nucleating agent have increased. This is because the α-nucleating agent can increase the crystallization speed and make a large number of crystals. The particle size is miniaturized and evenly distributed in the polypropylene matrix to improve the light transmittance.

Comparing Comparative Example 4 and Example 1, it can be seen that adding other types of POE, although the impact strength increases, affects the haze and greatly increases the haze, so the use of OBC can better achieve the desired effect.

It can be seen from the examples that the combination of antioxidants 1010, DSTP and 168 is the best, and OBC9507 and 9500 are more effective than adding them alone in equal proportions.

The invention provides a method for preparing radiation-resistant medical polypropylene for low-temperature centrifuge tubes. Through the synergistic effect of polyolefin elastomer OBC, composite nucleating agent and antioxidant, it not only improves low-temperature resistance, Radiation resistance, and also adds high transparency on this basis.

Claims (10)

1. The medical polypropylene for the low-temperature centrifuge tube and irradiation resistance is characterized by comprising the following raw materials in parts by mass:

polypropylene resin: 75-95 parts

Polyolefin elastomer: 5-25 parts

Composite nucleating agent: 0.2-1.0 part

An antioxidant: 0.05-0.5 part.

2. The medical polypropylene for low-temperature centrifuge tubes and radiation resistance according to claim 1, wherein the polypropylene resin is any one or more of polypropylene copolymer (PPR or PPB) and Polypropylene Homo (PPH).

3. A medical polypropylene for use in a cryogenic centrifuge tube, radiation resistant according to claim 1, wherein the polypropylene melt flow index is in the range of 10-30g/10 min; the polyolefin elastomer has a density of 0.85 to 0.95g/cm ³ Range.

4. The medical polypropylene for use in a low temperature centrifuge tube and resistant to irradiation of claim 1, wherein said polyolefin elastomer is any one of OBC-9507, OBC-9100, and OBC-9500.

5. The medical polypropylene for low-temperature centrifuge tubes and radiation resistance according to claim 1, wherein the polyolefin elastomer is an OBC-9507 and OBC-9500 compound, and the compounding ratio is 1:1.

6. The medical polypropylene for low-temperature centrifuge tubes and radiation resistance according to claim 1, wherein the composite nucleating agent is a compound combination of an alpha nucleating agent and a beta nucleating agent; the mass ratio of the two is 1:1-5:1;

the alpha nucleating agent is selected from any one or more of DMDBS (1, 3:2, 4-di (3, 4-dimethylbenzylidene) sorbitol), NA-11 (sodium 2,2 '-methylenebis (4, 6-di-tert-butylphenyl) phosphate), NA-21 (sodium 2, 2-methylenebis (4, 6-di-n-butylphenol) phosphate), NX8000 (bis-1, 3,2,4 (4' -propylbenzylidene) 1-propyl sorbitol;

the beta nucleating agent is selected from any one or more of NU-100 (N, N' -dicyclohexyl-2, 6-naphthalamide), DCHT (dicyclohexyl terephthalamide), TPDT (trimellitic acid), HPN-68 (bicyclo [2.2.1] heptane dicarboxylic acid sodium salt).

7. The medical polypropylene for low temperature centrifuge tube and radiation resistance according to claim 1, wherein the antioxidant is a combination of a primary antioxidant and an auxiliary antioxidant;

the main antioxidant is selected from any one of antioxidant 1098 (N, N '-bis- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylenediamine), antioxidant 1010 (tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol ester), antioxidant 1076 (beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate) stearyl ester), antioxidant 702 (4, 4' -methylenebis (2, 6-di-tert-butylphenol));

the auxiliary antioxidant is selected from any one or more of antioxidant DSTP (distearyl thiodipropionate), antioxidant 168 (phenyl tri (2, 4-di-tert-butyl) phosphite), antioxidant 9228 (bis (2, 4-dicumylphenyl) pentaerythritol-diphosphite) and antioxidant 300[4, 4' -thiobis (6-tert-butyl-3-methylphenol) ].

8. The medical polypropylene for low-temperature centrifuge tubes and radiation resistance according to claim 1, wherein the mass ratio of the primary antioxidant to the secondary antioxidant is 1: 1-1: 3.

9. the medical polypropylene for low-temperature centrifuge tubes and radiation resistance according to claim 1, wherein the polypropylene material is applied to medical freezing tubes and medical centrifuge tubes.

10. The method for preparing the medical polypropylene which is used for the low-temperature centrifuge tube and resistant to radiation according to claim 1, comprising the following steps: sequentially adding the polypropylene resin, the polyolefin elastomer, the composite nucleating agent and the antioxidant into a high-speed stirrer according to a certain proportion, uniformly mixing to obtain a mixture, adding the mixture into a main hopper of a double-screw extruder, and performing extrusion granulation to obtain the low-temperature-resistant irradiation-resistant high-transparency medical polypropylene, wherein the extrusion temperature is 160-210 ℃.