A low-extraction, high-glowing-filament toughened POM composition, and a preparation method and application thereof

Abstract

The application discloses a low-extraction high-glowing-filament toughened POM composition and a preparation method and application thereof. The POM composition comprises the following components in parts by weight: 100 parts of POM resin, 20-30 parts of thermoplastic polyurethane elastomer, and 10-20 parts of synergistic masterbatch. The synergistic masterbatch comprises the following components in percentage by weight: 50%-70% of polyamide and 30%-50% of melamine cyanurate. The application coats melamine cyanurate with polyamide in advance to form a synergistic masterbatch, and then mixes the synergistic masterbatch with the thermoplastic polyurethane elastomer, so that the degradation of POM in the extrusion process is reduced, and the low-extraction high-glowing-filament toughened POM composition is prepared. The glowing-filament flammability index of the composition can reach 650 DEG C / 2.0mm, and the composition is not prone to mold fouling in the processing process.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a toughened POM composition with low precipitation and high glow point, its preparation method, and its application. Background Technology

[0002] Polyoxymethylene (POM) is a highly crystalline engineering plastic with excellent mechanical properties, good wear resistance, and creep resistance. It is widely used in electronics, industrial machinery, office equipment, home appliances, automobiles and other fields.

[0003] However, POM resin has a low glow wire flammability index, especially for POM materials used in electrical components, which require good glow wire performance. Generally, a glow wire flammability index (GWFI) of 650℃ / 2.0mm is required, but currently, the GWFI of POM resin can only reach 550℃, which is far from meeting the requirements. Moreover, because POM resin is a highly crystalline polymer, it has poor compatibility with other additives, which makes it easy to precipitate during the preparation process.

[0004] Therefore, there is an urgent need to obtain a toughened POM composition with low precipitation and high glow wire. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a toughened POM composition with low precipitation and high glow wire, its preparation method, and its application. The POM composition provided by the present invention simultaneously possesses high glow wire and low precipitation properties.

[0006] The technical solution adopted in this invention is as follows:

[0007] A toughened POM composition with low precipitation and high glow point, characterized in that it comprises the following components in parts by weight:

[0008] 100 parts of POM resin;

[0009] 20-30 parts of thermoplastic polyurethane elastomer;

[0010] Synergistic masterbatch 10-20 parts;

[0011] The synergistic masterbatch comprises the following components in weight percentage: 50%-70% polyamide and 30%-50% melamine cyanurate.

[0012] The thermoplastic polyurethane elastomer is 20-30 parts by weight, for example, 22 parts, 24 parts, 26 parts, 28 parts, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0013] The weight parts of the synergistic masterbatch are 10-20 parts, for example, 12 parts, 14 parts, 16 parts, 18 parts, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0014] Preferably, the synergistic masterbatch comprises the following components in weight percentage: 60% polyamide and 40% melamine cyanurate.

[0015] Preferably, the polyamide is a polyamide resin with a melting point between 145-170°C.

[0016] Preferably, the POM resin has a melt index of 2.5-27 g / 10 min under test conditions of 190°C and 2.16 kg. The POM resin may be selected from homopolymer POM and / or copolymer POM, and the mass percentage of the POM resin in the composition is not less than 65%.

[0017] Preferably, the Shore hardness of the thermoplastic polyurethane elastomer is 80-90A according to the testing standard ISO 7619-1.

[0018] Preferably, the Shore hardness of the thermoplastic polyurethane elastomer is 85A.

[0019] Preferably, the POM composition further includes a primary antioxidant and a secondary antioxidant; the primary antioxidant is a hindered phenolic antioxidant, and the secondary antioxidant is a phosphate ester antioxidant.

[0020] The POM composition of the present invention may also contain other additives such as lubricants, nucleating agents, and weathering agents.

[0021] The present invention also provides a method for preparing the toughened POM composition with low precipitation and high glow wire, comprising the following steps:

[0022] S1: Preparation of synergistic masterbatch;

[0023] S2: POM resin, thermoplastic polyurethane elastomer, synergistic masterbatch, primary antioxidant and secondary antioxidant are mixed in a high-speed mixer for 1-2 minutes to obtain a premix;

[0024] S3: The premixed material is melt-extruded, cooled, and granulated using a twin-screw extruder at 150℃-200℃ to obtain a POM composition.

[0025] Preferably, in step S1, the method for preparing the synergistic masterbatch includes: adding polyamide and melamine cyanurate together into a high-speed mixer and mixing for 2-5 minutes to obtain a premix; and then melting and extruding the premix through a twin-screw extruder at 160-210°C, cooling, and granulating to obtain the synergistic masterbatch.

[0026] The present invention also provides an application of the toughened POM composition with low precipitation and high glow wire described above in electrical components, such as for the manufacture of electrical products, electronic components, and peripheral components for electrical management.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention reduces the degradation of POM during the extrusion process by pre-coating melamine cyanurate with polyamide to form a synergistic masterbatch, and then mixing the synergistic masterbatch with thermoplastic polyurethane elastomer (TPU). This results in a toughened POM composition with low precipitation and high glow wire flammability index, which can reach 650℃ / 2.0mm, and is less prone to mold fouling during processing. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] <Preparation of Examples and Comparative Examples>

[0031] The raw materials used in the embodiments and comparative examples of this invention are all commercially available, wherein:

[0032] POM resin: POM M25-44, melt index 2.5 g / 10 min, purchased from DuPont, Inc., USA;

[0033] POM resin: POM M90-44, melt index 9g / 10min, purchased from Nantong Baotailing;

[0034] POM resin: POM M270-44, melt index 27g / 10min, purchased from Nantong Baotailing;

[0035] POM resin: POM 500P, melt index 15g / 10min, purchased from DuPont, USA;

[0036] POM resin: POM 100P, melt index 2.6 g / 10 min, purchased from DuPont, USA;

[0037] POM resin: POM C13021, melt index 13g / 10min, purchased from Celanese;

[0038] Thermoplastic polyurethane elastomer (TPU): Model AVALON 80AB, Shore hardness 80A, purchased from Huntsman;

[0039] Thermoplastic polyurethane elastomer (TPU): Model AVALON 85AB, Shore hardness 85A, purchased from Huntsman;

[0040] Thermoplastic polyurethane elastomer (TPU): Model AVALON 90AB, Shore hardness 90A, purchased from Huntsman;

[0041] Melamine cyanurate: Model MCA, purchased from Shandong Haiwang Chemical.

[0042] Synergistic Masterbatch A consists of the following components by weight percentage: polyamide resin (model ES-4, melting point 145℃, purchased from Shanghai Zhenwei Composite Materials): 60%, melamine cyanurate: 40%.

[0043] Synergistic Masterbatch B is composed of the following components by weight percentage: polyamide resin (model ES-6, melting point 170℃, purchased from Shanghai Zhenwei Composite Materials): 60%, melamine cyanurate: 40%.

[0044] The melamine cyanurate used in both Synergistic Masterbatch A and Synergistic Masterbatch B is the same product.

[0045] The main antioxidant is antioxidant 245, which was purchased from BASF (China) Co., Ltd.

[0046] The co-antioxidant is Antioxidant 168, purchased from BASF (China) Co., Ltd.

[0047] The preparation method of the synergistic masterbatch is as follows: polyamide resin and melamine cyanurate are added together to a high-speed mixer and mixed for 2-5 minutes to obtain a premix; the premix is ​​melt-extruded through a twin-screw extruder at 160-210℃, cooled, and granulated to obtain the synergistic masterbatch. The temperatures of each screw barrel from the feed port to the die head in the twin-screw extruder are: 160℃-170℃, 170℃-180℃, 170℃-190℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-210℃, with a screw speed of 200-300 rpm, a feed rate of 50-200 kg / h, and a vacuum degree of -0.1-0 MPa.

[0048] The formulations of the POM compositions in Examples 1-10 and Comparative Examples 1-6 are shown in Tables 1-2, and the preparation methods are as follows:

[0049] S1: POM resin, thermoplastic polyurethane elastomer, synergistic masterbatch, primary antioxidant and secondary antioxidant are mixed in a high-speed mixer for 1-2 minutes to obtain a premix;

[0050] S2: The premixed material is melt-extruded, cooled, and granulated using a twin-screw extruder at 150℃-200℃ to obtain a POM composition. The temperatures of each screw in the twin-screw extruder from the feed port to the die head are: 150℃-170℃, 170℃-180℃, 170℃-190℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, 170℃-200℃, with a screw speed of 200-300 rpm, a feed rate of 50-200 kg / h, and a vacuum degree of -0.1-0 MPa.

[0051] <Test Standards>

[0052] Glow wire GWFI: Test standard IEC 60695-2-12:2014, sample thickness 2.0mm;

[0053] Notched impact strength: Test standard ISO 180:2013, pendulum energy 2.75J;

[0054] Extrusion granulation properties: Observe the particle condition during the extrusion process. Normal particles have an intact surface and 1-2 vacuum holes in the middle, without crushing; foamed particles are expanded or fragmented.

[0055] Mold fouling: After extrusion, the material is dried at 90°C for 4 hours, and then injection molded at 200°C for 4 hours. After continuous injection molding, the weight change of the mold fouling collector at the vent is measured. The greater the weight, the more prone the material is to mold fouling.

[0056] Isothermal mass retention rate evaluation method: The mass retention rate of isothermal thermal weight loss under air conditions is used for evaluation. The sample is heated to 230℃ at 20℃ / min under air conditions, and then kept at 230℃ for 1 hour. The higher the mass retention rate, the better the thermal stability.

[0057] Table 1. Formulations (parts by weight) for Examples 1-11

[0058]

[0059]

[0060] Table 2. Comparative Examples 1-6 Formulations (parts by weight)

[0061]

[0062] Table 3. Performance test results of Examples 1-11

[0063]

[0064]

[0065] Table 4. Performance test results of Comparative Examples 1-6

[0066]

[0067] Results analysis:

[0068] Comparing Example 2 with Comparative Examples 1-2, it can be seen that the amount of thermoplastic polyurethane elastomer added affects the toughness, glow wire properties and processing properties of the composition, while the composition prepared within the addition range provided by the present invention has better toughness, glow wire properties and processing properties.

[0069] Comparing Example 2 and Comparative Examples 3-4, it can be seen that the amount of synergistic masterbatch added affects the toughness, glow wire properties, and processing properties of the composition. When the proportion of synergistic masterbatch is too small, the glow wire properties of the composition are low; when the proportion of synergistic masterbatch is too large, the toughness and processing properties of the composition decrease. The compositions prepared within the addition range provided by this invention simultaneously possess good toughness, glow wire properties, and processing properties.

[0070] Compared with Comparative Example 5, Example 2 shows that if polyurethane and melamine cyanurate are directly added to the composition without coating treatment, decomposition and foaming will occur during the extrusion granulation process, making continuous production impossible and greatly reducing its practicality.

[0071] Comparing Example 2 and Comparative Example 6, it can be seen that without the addition of the synergistic masterbatch, the glow wire performance of the composition is relatively low, with a GWFI of only 600°C for 2.0mm, which does not meet the application requirements. However, the addition of the synergistic masterbatch of this invention can effectively reduce the degradation of POM during the extrusion process, and the toughened POM composition prepared at the same time has high glow wire performance, with the glow wire flammability index of the material reaching 650°C / 2.0mm.

[0072] To investigate the effect of the component ratio of the synergistic masterbatch on the performance of the composition, experimental groups 1 to 3 were set up as shown in Table 5. Synergistic masterbatches were prepared according to the weight percentage formulations of experimental groups 1 to 3, and then POM compositions were prepared according to the formulation and method of Example 2. The performance of the POM compositions prepared using the synergistic masterbatches of each experimental group was tested, and the results are shown in Table 5.

[0073] Table 5

[0074] Components, wt% Experimental group 1 Experimental group 2 Experimental group 3 polyamide 50 60 70 melamine cyanurate 50 40 30 GWFI / 2.0mm, ℃ 650 650 650 <![CDATA[Notch impact strength, kj / m 2 > 19.6 22.8 21.5 Extrusion granulation normal normal normal Scale, mg 0.23 0.20 0.20 Isothermal mass retention rate, % 96.5 97.4 97.3

[0075] As can be seen from Table 5, the component ratio in the synergistic masterbatch of the present invention will affect the toughness of the POM composition, and the composition prepared by the synergistic masterbatch of test group 2 has better overall performance.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A toughened POM composition with low precipitation and high glow point, characterized in that, By weight, it includes the following components: 100 parts of POM resin; 20-30 parts of thermoplastic polyurethane elastomer; Synergistic masterbatch 10-20 parts; The synergistic masterbatch comprises the following components in weight percentage: 50%-70% polyamide and 30%-50% melamine cyanurate.

2. The toughened POM composition with low precipitation and high glow wire according to claim 1, characterized in that, The synergistic masterbatch comprises the following components in weight percentage: 60% polyamide and 40% melamine cyanurate.

3. The toughened POM composition with low precipitation and high glow point according to claim 1, characterized in that, The polyamide is a polyamide resin with a melting point between 145-170°C.

4. The toughened POM composition with low precipitation and high glow point according to claim 1, characterized in that, The POM resin has a melt flow index of 2.5-27 g / 10 min under test conditions of 190℃ and 2.16 kg.

5. The toughened POM composition with low precipitation and high glow point according to claim 1, characterized in that, The Shore hardness of the thermoplastic polyurethane elastomer is 80-90A.

6. The toughened POM composition with low precipitation and high glow point according to claim 1, characterized in that, The thermoplastic polyurethane elastomer has a Shore hardness of 85A.

7. The toughened POM composition with low precipitation and high glow point according to claim 1, characterized in that, The POM composition further includes a primary antioxidant and a secondary antioxidant; the primary antioxidant is a hindered phenolic antioxidant; and the secondary antioxidant is a phosphate ester antioxidant.

8. The method for preparing the toughened POM composition with low precipitation and high glow wire according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Preparation of synergistic masterbatch; S2: POM resin, thermoplastic polyurethane elastomer, and synergistic masterbatch are uniformly mixed in a high-speed mixer to obtain a premix; S3: The premixed material is melt-extruded, cooled, and granulated using a twin-screw extruder at 150℃-200℃ to obtain a POM composition.

9. The method for preparing the toughened POM composition with low precipitation and high glow point according to claim 7, characterized in that, Includes the following steps: S1: Preparation of synergistic masterbatch; S2: POM resin, thermoplastic polyurethane elastomer, synergistic masterbatch, primary antioxidant and secondary antioxidant are uniformly mixed in a high-speed mixer to obtain a premix; S3: The premixed material is melt-extruded, cooled, and granulated using a twin-screw extruder at 150℃-200℃ to obtain a POM composition.

10. The method for preparing the toughened POM composition with low precipitation and high glow point according to any one of claims 8-9, characterized in that, In step S1, the method for preparing the synergistic masterbatch includes: adding polyamide and melamine cyanurate into a high-speed mixer and mixing them uniformly to obtain a premix; melting and extruding the premix through a twin-screw extruder at 160~210℃, cooling, and granulating to obtain the synergistic masterbatch.

11. The use of the toughened POM composition with low precipitation and high glow wire according to any one of claims 1 to 7 in electrical components.

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