A polypropylene alloy material and its preparation method and application

Abstract

The present invention discloses a polypropylene alloy material. The polypropylene alloy material comprises, by weight, 60 to 70 parts of PP resin, 8 to 13.5 parts of ABS resin, 4 to 8 parts of PMMA resin, 2 to 5 parts of toughening modifier, 0.1 to 2 parts of compatibilizer, and 15 to 20 parts of talc; the PP resin is a copolymerized PP resin, and the melting index of the PP resin under the condition of 230°C / 2.16KG is 2.0 to 10.0g / 10min; the melting index of the PMMA resin under the condition of 220°C / 10KG is 5.0 to 8.0g / 10min; the toughening modifier is SBS, and the SBS is a linear structure. The polypropylene alloy material prepared by the present invention has good impact strength, bending modulus, and suitable breaking performance, excellent cost performance, and greatly reduces the impact of subsequent incineration on the environment during recycling.

Description

Technical Field

[0001] The invention belongs to the technical field of modified plastics, and more specifically, relates to a polypropylene alloy material and a preparation method and application thereof. Background Art

[0002] There are two commonly used nucleic acid diagnostic methods for the new coronavirus: viral nucleic acid-specific gene detection and viral genome sequencing. The most common method for detecting the specific nucleic acid sequence of the new coronavirus is fluorescent quantitative PCR (polymerase chain reaction). Regardless of the detection scheme, sampling swabs are required, including nasal swabs and throat swabs. At present, throat swab sampling methods are more widely used in my country.

[0003] The disposable swab (hereinafter referred to as swab) is mainly composed of a swab rod and a swab. The swab rod is made of acrylonitrile-butadiene-styrene copolymer (ABS), polypropylene (PP), polystyrene (PS) or wooden materials. Among them, ABS material should comply with the provisions of GB / T12672-2009 acrylonitrile-butadiene-styrene (ABS) resin; PP should comply with the provisions of GB / T12670-2008 polypropylene (PP) resin material; PS should comply with the provisions of GB / T12671-2008 polystyrene (PS) resin.

[0004] The above three material solutions each have their own advantages and disadvantages. Among them, ABS resin material has the best comprehensive performance, but the price is also the most expensive. With the continuous reduction of testing fees, its cost performance is getting lower and lower. PS material refers to high-impact polystyrene (HIPS), which has worse comprehensive performance than ABS and a moderate price. PP material has the highest cost performance, but its rigidity is poor, its impact strength is high, and it is not easy to break, which has a great impact on the convenience of the sampling process.

[0005] Domestic swab manufacturers mostly use ABS resin, but with the cost pressure of the testing industry, many companies are gradually using HIPS resin to reduce costs. However, as disposable consumables for medical testing, ABS and HIPS are basically incinerated and landfilled in subsequent recycling. ABS and HIPS contain benzene rings in their structures, and a large amount of toxic gas is generated during the incineration process. Relatively speaking, the toxicity of PP resin after incineration is much less, and the impact on environmental safety is much smaller.

[0006] Therefore, how to provide a modified composite material that meets the comprehensive performance requirements, has both cost-effectiveness and can reduce the environmental pollution caused by material recycling is the core issue that needs to be solved at this stage. Summary of the invention

[0007] In view of the above-mentioned existing technical problems, the purpose of the present invention is to provide a polypropylene alloy material. The polypropylene alloy material prepared by adopting a PP / ABS / PMMA three-phase blending system has good comprehensive performance and excellent cost-effectiveness, and the impact of incineration on the environment is greatly reduced during material recycling.

[0008] The second object of the present invention is to provide a method for preparing a polypropylene alloy material.

[0009] The third object of the present invention is to provide an application of a polypropylene alloy material in medical testing and sampling products.

[0010] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0011] A polypropylene alloy material comprises, by weight, 60-70 parts of PP resin, 8-13.5 parts of ABS resin, 4-8 parts of PMMA resin, 2-5 parts of toughening modifier, 0.1-2 parts of compatibilizer and 15-20 parts of talc; the PP resin is a copolymerized PP resin, and the melting index of the PP resin at 230°C / 2.16KG is 2.0-10.0g / 10min; the melting index of the PMMA resin at 220°C / 10KG is 5.0-8.0g / 10min; the toughening modifier is SBS, and the SBS has a linear structure.

[0012] Plastic swab sticks have certain performance requirements for materials when used. They require the materials to have certain rigidity and toughness, and to be easily broken under a certain force (measure the bending angle of the swab stick at the breaking point, 60-90° is preferred; when the breaking angle is less than 60°, the plastic swab stick is more likely to break during transportation and handling; when the breaking angle is greater than 90°, it is not easy to break during use). Pure HIPS resin has slightly poorer overall performance, while pure ABS resin has excellent overall performance and meets the requirements, but its cost is relatively high. Therefore, the inventors of the present application mixed PP resin, ABS resin and PMMA resin to form a three-phase blending system, which optimized the rigidity and strength of the polypropylene alloy material and avoided the problem of sudden performance changes after the non-PP phase was added in an excessive amount in the two-phase blending system; further, the present application also preferably selected medium melt index PMMA resin and medium-low melt index PP resin to improve the fluidity of the resin system, and selected linear SBS as a toughening modifier; the linear SBS has a similar molecular chain structure to the PP / PMMA molecular chain structure, and is easy to produce molecular chain entanglement when blended, and is combined with the styrene in ABS, and further cooperates with a compatibilizer to improve the compatibility effect of the three-phase blending system. Through the above optimization, the present invention provides a PP / ABS / PMMA polypropylene alloy material with good comprehensive performance, and its notched impact strength is controlled at 9 to 15KJ / m 2, the bending modulus is controlled at 2000-2200Mpa, and the fracture performance is suitable. The polypropylene alloy material has comprehensive performance between HIPS and ABS, and can well meet the performance requirements of plastic swab rods. In addition, at the same density, the content of polymerized organic matter in the polypropylene alloy material is reduced by about 15-20%, which greatly reduces the impact of subsequent incineration on the environment.

[0013] Specifically, the testing method for the notched impact strength of the PP resin is ISO 180-2019.

[0014] Specifically, the S (styrene) (mass ratio) in the SBS is ≥ 30%.

[0015] Preferably, the compatibilizer is one or both of EAA compatibilizer and EMA resin. The melt index of the compatibilizer under the condition of 190°C / 2.16kg is 1.5-10.0g / 10min.

[0016] Preferably, the compatibilizer is EMA resin. The present invention uses EMA resin as the compatibilizer of the system, and matches it with the toughening modifier SBS, achieving a good compatibilization and modification effect, which is better than traditional SEBS / SEEPS and other solutions.

[0017] Preferably, the ABS is an emulsion ABS resin, and the melt index of the ABS at 220°C / 10KG is 20.0-40.0g / 10min.

[0018] Preferably, the D of the talc is 50 The particle size is 1250~4000 mesh.

[0019] Preferably, the polypropylene alloy material further comprises 0.1 to 0.5 parts of an antioxidant and / or 0.5 to 1 parts of a lubricating dispersant, measured in parts by weight.

[0020] More preferably, the antioxidant is selected from one or more of hindered phenols, phosphites, thio or composite antioxidants.

[0021] Further preferably, the lubricating dispersant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, erucic acid amide or ethylene bisstearamide.

[0022] In addition, the present invention also provides a method for preparing a polypropylene alloy material, comprising stirring and mixing PP resin, ABS resin and PMMA resin, then adding a toughening modifier, a compatibilizer and talcum powder, stirring and mixing, and melt-extruding and granulating to prepare the polypropylene alloy material.

[0023] Preferably, the temperature of the melt extrusion is 200-210°C.

[0024] Preferably, a twin-screw extruder is used for melt extrusion, wherein the aspect ratio of the twin-screw extruder is 35 to 40:1 and the screw speed is 250 to 400 rpm.

[0025] Furthermore, the present invention also provides the application of the above-mentioned polypropylene alloy material in medical testing sampling products. More specifically, the polypropylene alloy material can be used as a swab stick in various medical testing sampling products, such as disposable plastic medical testing sampling sticks, COVID-19 testing swab sticks or other disposable consumables such as other medical testing sampling sticks.

[0026] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a polypropylene alloy material with good comprehensive performance, and its notched impact strength is controlled at 9-15KJ / m 2 The bending modulus is controlled at 2000-2200Mpa, and the breaking performance is suitable. The polypropylene alloy material has comprehensive performance between HIPS and ABS, and can well meet the performance requirements of the plastic swab stick. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the specification and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0028] Examples and Comparative Examples Raw Materials Description:

[0029] Polypropylene resin (PP resin 1), copolymer polypropylene, melt index at 230°C / 2.16KG is 2.9g / 10min; PP 2500H, PetroChina.

[0030] Polypropylene resin (PP resin 2), copolymerized polypropylene, melt index at 230°C / 2.16KG is 9.0g / 10min; PP SP179, Lanzhou Petrochemical.

[0031] Polymethyl methacrylate (PMMA resin 1), the melt index at 220°C / 10KG is 7.5 g / 10 min, PMMACM-207, Chi Mei Chemical, Taiwan, China.

[0032] Polymethyl methacrylate (PMMA resin 2), the melt index at 220°C / 10KG is 2.3 g / 10 min, PMMA IH-830, LG Chemical of South Korea.

[0033] Polymethyl methacrylate (PMMA resin 3), the melt index at 220°C / 10KG is 16 g / 10 min, PMMACM-211, Chi Mei Chemical, Taiwan, China.

[0034] Emulsion ABS resin (ABS1), melt index at 220℃ / 10KG is 38.0g / 10min, ABSDG-MG94, Tianjin Dagu Petrochemical.

[0035] Bulk ABS resin (ABS2), melt index at 220℃ / 10KG is 3.9g / 10min, ABS8434, Shanghai Gaoqiao.

[0036] Styrene-butadiene-styrene block copolymer (SBS1), linear structure, S (styrene) (mass ratio) is 40%, SBS YH-792, Yueyang Petrochemical.

[0037] Styrene-butadiene-styrene block copolymer (SBS2), star structure, S (styrene) (mass ratio) is 30%, SBS H6302T, Dushanzi Petrochemical.

[0038] POE toughening modifier, POE DF610, Dow Chemical, USA.

[0039] Ethylene-methyl acrylate copolymer (EMA resin), melt index at 190°C / 2.16kg is 1.9 g / 10 min, 1820AC, DuPont Chemical, USA.

[0040] Ethylene acrylic acid copolymer (EAA compatibilizer), melt index at 190°C / 2.16kg is 9.5 g / 10 min, EAA 2002, DuPont Chemical, USA.

[0041] Talc 1, D 50 The particle size is 1250 mesh, TY90-20-A, Shanghai Chuangyu Chemical.

[0042] Talc 2, D 50 The particle size is 3000 mesh, TYT-777A, Haicheng Tianyuan Chemical.

[0043] Calcium carbonate, D 50 The particle size is 1500 mesh, F-21, Sichuan Mianzhu Hongyang Powder Company.

[0044] Antioxidant: Antioxidant 1010, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, commercially available.

[0045] Antioxidant 168, tris[2,4-di-tert-butylphenyl]phosphite, commercially available.

[0046] Lubricating dispersant: ethylene bis stearamide (EBS), commercially available.

[0047] Calcium stearate, commercially available.

[0048] Unless otherwise specified, the components (eg antioxidant, lubricating dispersant) selected in each parallel embodiment and comparative example are the same commercially available products.

[0049] Examples 1 to 10

[0050] The weight parts of the raw materials used in the following examples are shown in Table 1.

[0051] The following examples adopt the same preparation method, and the specific steps include:

[0052] (1) Weigh the raw materials according to the weight parts in Table 1, and put the above raw materials into a high-speed mixer according to the process settings. The stirring time of the mixer is 3 minutes. The twin-screw plastic extruder (screw aspect ratio 38:1) is used for extrusion. The body temperature is 200-210°C, the head temperature is 220°C, and the main engine speed is 300r / min. The extruded material is cooled at 20°C water temperature and then pelletized to prepare a polypropylene alloy material.

[0053] Table 1 is the formula components of each embodiment:

[0054] Table 1

[0055]

[0056]

[0057] Comparative Examples 1 to 9

[0058] The weight parts of the raw materials used in the following comparative examples are shown in Table 2.

[0059] The specific preparation steps of each comparative example are the same as those of Example 1.

[0060] Table 2 shows the formula components of each comparative example:

[0061] Table 2

[0062]

[0063] The polypropylene alloy materials prepared in the above examples and comparative examples were tested according to the following test methods:

[0064] Flexural modulus: tested using the test method of ISO 178-2012, with a tensile speed of 2 mm / min.

[0065] Izod notched impact strength: tested using the ISO 180-2019 test method (23°C, 2 mm injection notch).

[0066] Evaluation method of fracture index: The polypropylene alloy material in the above embodiment and comparative example is prepared into a swab stick by an injection molding machine, the sampling end of the sampling swab is fixed, and the swab stick is bent at a rate of 2 mm / second. When the swab breaks, the test instrument automatically stops moving. At this time, the bending angle of the swab stick at the breaking point is measured. 60 to 90 degrees is preferred. The smaller the angle, the easier it is to break, and the larger the angle, the harder it is to break.

[0067] Table 3

[0068]

[0069] Table 4

[0070]

[0071] It can be seen from the above examples that the polypropylene alloy material prepared by the present invention has good comprehensive properties, and its notched impact strength is controlled at 9-15KJ / m 2 The bending modulus is controlled at 2000-2200Mpa, and has suitable breaking performance. The polypropylene alloy material has comprehensive performance between HIPS and ABS, and can well meet the performance requirements of the plastic swab stick.

[0072] It can be seen from Example 2 that Example 1 preferably uses EMA resin as a compatibilizer and matches it with a toughening modifier SBS, achieving a good compatibilization and modification effect. The prepared polypropylene alloy material has suitable fracture properties, and both the flexural modulus and the impact strength are improved.

[0073] It can be seen from Examples 1, 4 and 6 that Example 1 preferably uses PP resin and ABS resin with specific melt index, which can improve the fluidity of the resin system, and the prepared polypropylene alloy material has suitable breaking properties and significantly improved impact strength.

[0074] From Comparative Example 1 and Example 1, it can be seen that the notched impact strength of the SBS with a star structure is greatly affected, and the flexural modulus is slightly reduced. From Comparative Examples 2 to 3 and Example 1, it can be seen that the melt index of the preferred PMMA resin in Example 1 has a significant improvement on the impact strength and suitable fracture performance of the polypropylene alloy material.

[0075] It can be seen from Comparative Example 4 and Example 1 that the flexural modulus, impact strength and fracture performance of the polypropylene alloy material using calcium carbonate as the raw material are significantly reduced, which shows that the use of talcum powder has an important influence on the flexural modulus, impact strength and fracture performance of the polypropylene alloy material.

[0076] From Comparative Examples 5 to 6 and Example 1, it can be seen that the specific amount of ABS resin used in Example 1 has a great influence on the bending modulus, impact strength and fracture performance of the polypropylene alloy material. When the ABS resin is higher or lower than the specific amount, the polypropylene alloy material is difficult to achieve the technical effect. From Comparative Example 7 and Example 1, it can be seen that the use of PMMA resin can effectively improve the bending modulus and impact strength of the polypropylene alloy material and have suitable fracture performance.

[0077] It can be seen from Comparative Example 8 that the polypropylene alloy material can achieve the technical effect only when the toughening modifier used in Example 1 is SBS. It can be seen from Comparative Example 9 that the amount of PP, PMMA and ABS has a great influence on the bending modulus, impact strength and fracture performance of the polypropylene alloy material, and the prepared polypropylene alloy material is difficult to break.

[0078] In summary, the present invention provides a polypropylene alloy material with good comprehensive performance, and its notched impact strength is controlled at 9-15KJ / m 2 The bending modulus is controlled at 2000-2200Mpa, and the breaking angle when prepared into a swab stick is 60-90°. The polypropylene alloy material has comprehensive properties between HIPS and ABS, and can well meet the performance requirements of plastic swab sticks.

[0079] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to require the widest possible range that can be imagined, and the embodiments presented herein are demonstrated by the applicant's actual test results. Therefore, the applicant's intention is that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges therein, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A polypropylene alloy material, It is characterized in that In terms of weight, it includes: 60-70 parts of PP resin, 8-13.5 parts of ABS resin, 4-8 parts of PMMA resin, 2-5 parts of toughening modifier, 0.1-2 parts of compatibilizer, and 15-20 parts of talc; The PP resin is a copolymerized PP resin, and the melt index of the PP resin at 230° C. / 2.16KG is 2.0 to 10.0 g / 10 min; The melt index of the PMMA resin at 220°C / 10KG is 5.0-8.0g / 10min; The toughening modifier is SBS, and the SBS has a linear structure; The compatibilizer is one or both of EAA compatibilizer and EMA resin.

2. The polypropylene alloy material according to claim 1, It is characterized in that The ABS resin has a melt index of 20.0 to 40.0 g / 10 min at 220° C. / 10 kg.

3. The polypropylene alloy material according to claim 1, It is characterized in that The compatibilizer is EMA resin.

4. The polypropylene alloy material according to claim 1, It is characterized in that The D of the talc 50 The particle size is 1250~4000 mesh.

5. The polypropylene alloy material according to claim 1, It is characterized in that In terms of weight, the polypropylene alloy material further comprises 0.1 to 0.5 parts of an antioxidant and / or 0.5 to 1 parts of a lubricating dispersant.

6. The polypropylene alloy material according to claim 5, It is characterized in that The antioxidant is selected from one or more of hindered phenols, phosphites, thiols or composite antioxidants.

7. The polypropylene alloy material according to claim 5, It is characterized in that The lubricating dispersant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, erucic acid amide or ethylene bis stearamide.

8. The method for preparing the polypropylene alloy material according to any one of claims 1 to 4, It is characterized in that The PP resin, ABS resin and PMMA resin are stirred and mixed, and then a toughening modifier, a compatibilizer and talcum powder are added and stirred and mixed, and melt-extruded and granulated to prepare a polypropylene alloy material.

9. Use of the polypropylene alloy material according to any one of claims 1 to 7 in medical testing and sampling products.

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