Hypophosphite flame-retardant PPS composite material as well as preparation method and application thereof

Abstract

The invention discloses a hypophosphite flame-retardant PPS composite material as well as a preparation method and application thereof, and relates to the technical field of polyphenylene sulfide composite materials. The invention provides a hypophosphite flame-retardant PPS (polyphenylene sulfide) composite material. The hypophosphite flame-retardant PPS composite material comprises the following components in parts by weight: 50-90 parts of PPS resin, 10-50 parts of glass fibers, 1-10 parts of a styrene thermoplastic elastomer, 4-8 parts of a hypophosphite flame retardant and 0.5-3 parts of phosphate. The hypophosphite flame-retardant PPS composite material with high flame retardance, high toughness and tracking resistance is prepared through the cooperation of the PPS resin, the styrene thermoplastic elastomer, the hypophosphite flame retardant and the phosphate.

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene sulfide composite materials, in particular to a hypophosphite flame-retardant PPS composite material and a preparation method and application thereof. Background Art

[0002] Polyphenylene sulfide (PPS) is widely used in aerospace, automotive functional parts and other fields due to its good mechanical properties, self-flammability, excellent fatigue performance and temperature resistance. However, polyphenylene sulfide materials also have obvious disadvantages. When high voltage is applied to the surface of the insulator, the electric tracking damage caused by PPS resin is worse than other engineering plastics such as polyamide resin and polyester resin. The poor tracking resistance of polyphenylene sulfide limits its application in high-voltage electrical systems.

[0003] The hypophosphite flame retardant polyphenylene sulfide system has high flame retardant efficiency, a small amount of addition compared to other flame retardants, and little impact on performance. However, after adding the hypophosphite flame retardant to PPS, the hypophosphite will promote carbonization to form a conductive path, further reducing the resistance to leakage tracking of PPS. At this time, other leakage tracking improvers have no obvious effect on improving the leakage tracking of the system. In addition, in actual application, the product has low toughness and is easy to crack during use, and the product risk is high in the field of vehicle-mounted. For example, patent CN103827213 adds polyamide resin and metal hydroxide, and disperses them with an average particle size of less than 5μm to obtain a PPS resin composition with excellent resistance to leakage tracking, mechanical strength, and low gas properties. However, a large amount of metal hydroxide causes the toughness of the material to be low. When the product is used, cracking is prone to occur.

[0004] Therefore, a hypophosphite flame-retardant PPS composition with high flame retardancy, high toughness and resistance to tracking has broad application prospects. Summary of the invention

[0005] Based on this, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a hypophosphite flame-retardant PPS composite material with good flame retardancy, high toughness and resistance to leakage tracking, as well as a preparation method and application thereof.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a hypophosphite flame-retardant PPS composite material, comprising the following components in parts by weight: 50-90 parts of PPS resin, 10-50 parts of glass fiber, 1-10 parts of styrene-based thermoplastic elastomer, 4-8 parts of hypophosphite flame retardant, and 0.5-3 parts of phosphate.

[0007] Preferably, the styrene-based thermoplastic elastomer includes at least one of styrene-based thermoplastic elastomer SBS, styrene-ethylene-butylene-styrene block copolymer SEBS, styrene-ethylene-propylene-styrene block copolymer SEPS, and styrene-isobutylene-styrene triblock copolymer SIBS.

[0008] Preferably, the hypophosphite flame retardant PPS composite material comprises the following components in parts by weight: 3-6 parts of styrene-based thermoplastic elastomer, 4-6 parts of hypophosphite flame retardant, and 1-2 parts of phosphate.

[0009] Preferably, the mass percentage of styrene in the styrene-based thermoplastic elastomer is 20-70%, preferably, the mass percentage of styrene in the styrene-based thermoplastic elastomer is 35-45%. The mass percentage of styrene in the styrene-based thermoplastic elastomer is tested according to ASTM D5775-2014 standard.

[0010] Preferably, the weight percentage of the PPS resin in the hypophosphite flame-retardant PPS composite material is not less than 40%.

[0011] The present invention prepares a high flame retardant, high toughness, and anti-tracking hypophosphite flame retardant PPS composite material through the synergy of PPS resin, styrene thermoplastic elastomer, hypophosphite flame retardant, and phosphate. On the one hand, the hypophosphite flame retardant and phosphate can synergize to improve the flame retardancy under the premise of reducing the amount of hypophosphite flame retardant added; at the same time, during the CTI test, PPS resin and hypophosphite will promote carbonization to form a conductive path, resulting in failure of the anti-tracking test. However, the introduction of phosphate can destroy the original conductive path during the anti-tracking test, thereby significantly improving the anti-tracking property. On the other hand, the carbonization of styrene thermoplastic elastomer is weaker than that of PPS, which can improve the anti-tracking property; at the same time, styrene thermoplastic elastomer, hypophosphite flame retardant, and phosphate can further improve the anti-tracking property.

[0012] The inventors found in actual experiments that when the mass percentage of styrene in the styrene-based thermoplastic elastomer is 35-45%, the prepared hypophosphite flame-retardant PPS composite material has better resistance to leakage tracking and toughness while ensuring flame retardancy.

[0013] Optionally, the weight of the PPS resin is 50 parts, 51 parts, 53 parts, 55 parts, 58 parts, 60 parts, 61 parts, 63 parts, 65 parts, 68 parts, 70 parts, 72 parts, 75 parts, 80 parts, 82 parts, 85 parts, 88 parts, 90 parts or any two of the range values; the glass fiber is 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 21 parts, 23 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts or any two of the range values; the styrene-based thermoplastic elastomer is 1 part , 1.5 parts, 2 parts, 2.3 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts or any two of the range values; the hypophosphite flame retardant is 4 parts, 4.5 parts, 5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts or any two of the range values; the phosphate is 0.5 parts, 0.8 parts, 1 part, 1.1 parts, 1.3 parts, 1.5 parts, 2 parts, 2.1 parts, 2.3 parts, 2.5 parts, 3 parts or any two of the range values.

[0014] Preferably, the hypophosphite flame retardant includes at least one of aluminum hypophosphite, calcium hypophosphite and magnesium hypophosphite.

[0015] Preferably, the phosphate includes at least one of calcium phosphate, sodium phosphate, potassium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and hydroxyphosphate. Further preferably, the hydroxyphosphate includes at least one of ferric hydroxyphosphate, calcium hydroxyphosphate, sodium hydroxyphosphate, and potassium hydroxyphosphate.

[0016] Preferably, the hypophosphite flame retardant PPS resin has a melt mass flow rate of ≥500 g / 10 min at a test temperature of 316° C. and a load of 5 kg according to ISO 1133-2022. Further preferably, the PPS resin has a melt mass flow rate of 500-1800 g / 10 min at a test temperature of 316° C. and a load of 5 kg according to ISO 1133-2022.

[0017] Optionally, the hypophosphite flame retardant PPS resin has a melt mass flow rate of 500 g / 10min, 550 g / 10min, 600 g / 10min, 650 g / 10min, 700 g / 10min, 800 g / 10min, 900 g / 10min, 1000 g / 10min, 1100 g / 10min, 1200 g / 10min, 1250 g / 10min, 1300 g / 10min, 1350 g / 10min, 1400 g / 10min, 1450 g / 10min, 1500 g / 10min, 1600 g / 10min, 1700 g / 10min, 1800 g / 10min or any two of the range values ​​under the conditions of a test temperature of 316° C. and a load of 5 kg according to ISO 1133-2022.

[0018] Preferably, the glass fiber is a chopped glass fiber, the diameter of the chopped glass fiber is 10-15 μm, the length is 3-6 mm, and the surface is treated with polyurethane. The glass fiber treated with polyurethane on the surface can improve the compatibility of the glass fiber and other components, improve the dispersibility of the glass fiber, and thus improve the dimensional stability of the product. Optionally, the diameter of the chopped glass fiber is measured using an optical microscope, and the length is measured using a vernier caliper.

[0019] Preferably, the hypophosphite flame-retardant PPS composite material further comprises 0.1-3.5 parts of a processing aid, wherein the processing aid is at least one of a lubricant, a colorant, and an antioxidant.

[0020] Optionally, the weight portion of the antioxidant is 0.1-0.5 parts, and the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant, such as antioxidant 168 (tris[2.4-di-tert-butylphenyl]phosphite), antioxidant 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), etc.

[0021] Optionally, the weight portion of the lubricant is 0.1-1 part, and the lubricant is at least one of stearates, stearic acid esters, and ethylene bis stearic acid amides, such as pentaerythritol stearate, zinc stearate, and the like.

[0022] Optionally, the weight portion of the colorant is 0.1-2 parts, and the colorant is at least one of zinc sulfide, carbon black, iron red, titanium dioxide, and iron yellow.

[0023] In addition, the present invention provides a method for preparing the hypophosphite flame-retardant PPS composite material, comprising the following steps: uniformly mixing the components in proportion to obtain a mixture A; adding the mixture A to a main feed port of a screw extruder, adding glass fiber to a side feed port of the screw extruder, and performing melt extrusion and granulation to obtain the hypophosphite flame-retardant PPS composite material.

[0024] Preferably, the temperature of the melt extrusion is 220-320°C.

[0025] Furthermore, the present invention provides the use of the hypophosphite flame retardant PPS composite material in automotive electronics, industrial equipment, and household appliances. Optionally, the present invention provides the use of the hypophosphite flame retardant PPS composite material in wafer boxes, turnover boxes, and battery poles.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention prepares a high flame retardant, high toughness, and tracking resistance hypophosphite flame retardant PPS composite material through the synergy of PPS resin, styrene thermoplastic elastomer, hypophosphite flame retardant, and phosphate. On the one hand, the synergy of hypophosphite flame retardant and phosphate can improve the flame retardancy under the premise of reducing the amount of hypophosphite flame retardant added; at the same time, during the CTI test, hypophosphite will promote carbonization to form a conductive path, resulting in failure of the tracking resistance test. However, the introduction of phosphate can destroy the original conductive path during the tracking resistance test, thereby significantly improving the tracking resistance. On the other hand, the carbonization of styrene thermoplastic elastomer is weaker than that of PPS, which can improve the tracking resistance; at the same time, the synergy of styrene thermoplastic elastomer, hypophosphite flame retardant, and phosphate can further improve the tracking resistance. DETAILED DESCRIPTION

[0027] To better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, the purpose of which is to understand the content of the present invention in detail, rather than to limit the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The experimental reagents and instruments involved in the implementation of the present invention are all commonly used ordinary reagents and instruments unless otherwise specified.

[0028] The raw materials used in the embodiments and comparative examples are described below, as shown in Table 1, but are not limited to these materials:

[0029] Table 1

[0030]

[0031] The glass fiber is glass fiber ECS309A-3-H, purchased from Chongqing International Composite Materials, with a length of 3 mm and a surface coated with 1 wt % polyurethane.

[0032] The antioxidant is a composite of a commercially available hindered phenol antioxidant 1010 and a commercially available phosphite antioxidant 168 in a mass ratio of 1:1.

[0033] The lubricant is pentaerythritol stearate, which is commercially available.

[0034] Examples 1-14 and Comparative Examples 1-4

[0035] The hypophosphite flame-retardant PPS composite material of the present invention has components as shown in Table 2 to Table 4. The preparation method of the hypophosphite flame-retardant PPS composite material comprises the following steps:

[0036] (1) Weigh each component according to the ratio;

[0037] (2) mixing PPS resin, styrene-based thermoplastic elastomer, hypophosphite flame retardant, phosphate, antioxidant, and lubricant to obtain a mixture A;

[0038] (3) Adding mixture A to the main feed port of a twin-screw extruder, adding glass fiber to the side feed port of the twin-screw extruder, the screw temperature of each section of the twin-screw extruder is 220-320° C., and performing melt extrusion and granulation to obtain a hypophosphite flame-retardant PPS composite material.

[0039] Table 2

[0040]

[0041]

[0042] Table 3

[0043]

[0044] Table 4

[0045]

[0046]

[0047] Performance Testing

[0048] Vertical burning test: UL94-2018; the injection molding specification is a standard test piece of 125*13*0.8mm, tested using a vertical burning tester; according to the standard, the test results include V-0, V-1, V-2, V-2 cannot be achieved, etc.

[0049] Tracking resistance test: IEC 60112-2020, injection molding specification is 100*100*3mm standard test piece, tested with tracking tester, unit is V.

[0050] Toughness: Characterized by bending deflection, the test method is ISO 178-2010, using an electronic universal testing machine for testing, the injection molding specification is a standard test piece of 80*10*4mm, the test rate is 2mm / min, and the unit is mm.

[0051] The results of the performance test are shown in Table 5.

[0052] Table 5

[0053]

[0054]

[0055] As can be seen from the above table, Examples 1-14 of the present invention prepare highly flame-retardant, high-toughness, and tracking-resistant hypophosphite flame-retardant PPS composite materials through the synergy of PPS resin, styrene-based thermoplastic elastomer, hypophosphite flame retardant, and phosphate.

[0056] From the comparison between Example 1 and Examples 3-7, it can be seen that when the mass percentage of styrene in the styrene-based thermoplastic elastomer is 35-45%, the prepared hypophosphite flame-retardant PPS composite material has better tracking resistance and toughness while ensuring flame retardancy.

[0057] From the comparison between Example 1 and Examples 11-14, it can be seen that when the hypophosphite flame-retardant PPS composite material contains 3-6 parts of styrene thermoplastic elastomer, 4-6 parts of hypophosphite flame retardant, and 1-2 parts of phosphate, the tracking resistance is better while ensuring flame retardancy and toughness.

[0058] From the comparison between Example 1 and Comparative Example 1, it can be seen that too much weight of phosphate in the hypophosphite flame-retardant PPS composite material has a great influence on the toughness, and the toughness is below 3 mm, which cannot meet the requirements.

[0059] From the comparison between Example 1 and Comparative Example 2, it can be seen that when no styrene-based thermoplastic elastomer is present, the tracking resistance and toughness of the hypophosphite flame-retardant PPS composite material are poor and cannot meet the requirements.

[0060] From the comparison between Example 1 and Comparative Example 3, it can be seen that after the phosphate is replaced by calcium borate, the toughness of the hypophosphite flame-retardant PPS composite material decreases, and the tracking resistance is extremely poor, which cannot meet the requirements.

[0061] From the comparison between Example 1 and Comparative Example 4, it can be seen that when no phosphate is present, the hypophosphite flame-retardant PPS composite material has extremely poor tracking resistance and a flame retardant performance of V-2, which cannot meet the requirements.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A hypophosphite flame-retardant PPS composite material, characterized in that: The invention comprises the following components in parts by weight: 50-90 parts of PPS resin, 10-50 parts of glass fiber, 1-10 parts of styrene thermoplastic elastomer, 4-8 parts of hypophosphite flame retardant and 0.5-3 parts of phosphate.

2. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 3-6 parts of styrene-based thermoplastic elastomer, 4-6 parts of hypophosphite flame retardant and 1-2 parts of phosphate.

3. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: The styrene-based thermoplastic elastomer includes at least one of styrene-based thermoplastic elastomer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene type block copolymer, and styrene-isobutylene-styrene triblock copolymer.

4. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: The mass percentage of styrene in the styrene-based thermoplastic elastomer is 20-70%; preferably, the mass percentage of styrene in the styrene-based thermoplastic elastomer is 35-45%.

5. The hypophosphite flame-retardant PPS composite material according to claim 4, characterized in that: The hypophosphite flame retardant includes at least one of aluminum hypophosphite, calcium hypophosphite and magnesium hypophosphite.

6. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: The phosphate includes at least one of calcium phosphate, sodium phosphate, potassium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and hydroxyphosphate; preferably, the hydroxyphosphate includes at least one of hydroxyferric phosphate, hydroxycalcium phosphate, hydroxysodium phosphate, and potassium hydroxyphosphate.

7. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: According to ISO1133-2022, the PPS resin has a melt mass flow rate of ≥500 g / 10 min under the conditions of a test temperature of 316° C. and a load of 5 kg.

8. The hypophosphite flame-retardant PPS composite material according to claim 1, characterized in that: The hypophosphite flame-retardant PPS composite material further comprises 0.1-3.5 parts of a processing aid, wherein the processing aid is at least one of a lubricant, a colorant and an antioxidant.

9. A method for preparing the hypophosphite flame-retardant PPS composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are mixed uniformly in proportion to obtain a mixture A; the mixture A is added to the main feeding port of the screw extruder, and the glass fiber is added to the side feeding port of the screw extruder, and the mixture is melt-extruded and granulated to obtain a hypophosphite flame-retardant PPS composite material.

10. Use of the hypophosphite flame-retardant PPS composite material according to any one of claims 1 to 8 in automotive electronics, industrial equipment, and household appliances.

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