A polyphenylene ether composite material, its preparation method and application

Abstract

The present invention discloses a polyphenylene ether composite material, which comprises 50 - 80 parts by weight of polyphenylene ether, 0 - 20 parts by weight of a flame retardant, alkali metal hypophosphite and / or alkaline earth metal hypophosphite; wherein, based on the total weight of the polyphenylene ether composite material, the content of P element from the alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1000 - 3000 ppm. The present invention uses a specific content of alkali metal hypophosphite and / or alkaline earth metal hypophosphite to replace part or all of the commonly used phosphite antioxidants, thioester antioxidants, hindered phenol antioxidants and amine antioxidants, which can significantly improve the irregular decrease of the melt index caused by the rearrangement of polyphenylene ether during the high-temperature melting process, thereby improving the high-temperature injection molding processing stability and improving processing and injection molding appearance defects such as flow marks. Especially when the flame retardant is a polyphosphazene flame retardant, the effect is more significant.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to a polyphenylene ether composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Polyphenylene ether materials (abbreviated as PPE) have been widely used in the electrical field due to their excellent insulation performance, flame retardancy, and heat resistance. During actual use, the viscosity of pure PPE materials is relatively high and the processing difficulty is great. Generally, a certain amount of PS needs to be added to adjust the fluidity, but the addition of PS will reduce the flame retardancy of the material. At the same time, since both PS and PPE are rigid materials and their glass transition temperatures are much higher than room temperature, the processing temperature of PPE materials is about 300°C, which easily leads to appearance problems.

[0003] At the same time, in order to improve the flame retardancy of the material to reach V-0, the currently adopted methods are mainly adding halogen-free flame retardants or the compounding method of halogen-free flame retardants and flame retardant synergists. However, the addition of these flame retardants further reduces the stability of polyphenylene ether materials while improving the flame retardancy of the material, and aggravates the irregular decrease in fluidity caused by the rearrangement of polyphenylene ether resin during the high-temperature melting process.

[0004] Patent US6479572 effectively improves the processing stability of the material through antioxidant IRganox 1076 and phosphite antioxidants. Patent US4309335 improves the stability of the material during long-term use by introducing phosphite. Patent US4021468 improves the stability of the material during the processing process by introducing organic sulfides. However, with the progress of processing technology, more and more factories use hot runners to avoid losses such as runners, which will lead to processing temperatures much higher than the processing temperature of traditional polyphenylene ether materials. However, under high-temperature conditions, traditional phosphite antioxidants, thioester antioxidants, hindered phenol antioxidants, and amine antioxidants cannot inhibit the rearrangement reaction that easily occurs during the high-temperature processing of polyphenylene ether, resulting in an irregular decrease in the melt index during the flow of the melt during the injection molding process, leading to processing and injection molding appearance defects such as flow marks. Summary of the Invention

[0005] The purpose of the present invention is to provide a polyphenylene ether composite material with good injection molding appearance, a preparation method thereof, and an application thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A polyphenylene ether composite material, by weight, comprises 50 - 80 parts of polyphenylene ether, 0 - 20 parts of flame retardant, alkali metal hypophosphite and / or alkaline earth metal hypophosphite; wherein, based on the total weight of the polyphenylene ether composite material, the content of P element from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1000 - 3000 ppm.

[0008] The alkali metal hypophosphite and / or alkaline earth metal hypophosphite is selected from at least one of sodium hypophosphite and calcium hypophosphite.

[0009] Preferably, based on the total weight of the polyphenylene ether composite material, the content of P element from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1500 - 2000 ppm.

[0010] In the polyphenylene ether resin, common flame retardants can be phosphate ester flame retardants (such as bisphenol A bis(diphenyl phosphate), triphenyl phosphate, etc.). Preferably, the flame retardant is selected from polyphosphazene flame retardants. When using polyphosphazene flame retardants for flame retardant modification of polyphenylene ether, it will aggravate the rearrangement reaction during the high-temperature processing of polyphenylene ether, resulting in changes in melt fluidity. However, after adding alkali metal hypophosphite and / or alkaline earth metal hypophosphite, the improvement effect is more significant compared to when there is no flame retardant.

[0011] Specifically, the polyphosphazene flame retardant is selected from at least one of cyclotriphosphazene compounds, cyclotetraphosphazene compounds, cyclopentaphosphazene compounds, and linear phosphazene compounds; the cyclotriphosphazene compounds are selected from at least one of hexaphenoxycyclotriphosphazene, monocyanophenoxypentaphenoxycyclotriphosphazene, dicyanophenoxytetraphenoxycyclotriphosphazene, tricyanophenoxytriphenoxycyclotriphosphazene, tetracyanophenoxydiphenoxycyclotriphosphazene, and pentacyanophenoxymonophenoxycyclotriphosphazene; the cyclotetraphosphazene compounds are selected from monocyanophenoxyheptaphenoxycyclotetraphosphazene, dicyanophenoxyhexaphenoxycyclotetraphosphazene, tricyanophenoxypentaphenoxycyclotetraphosphazene, tetracyanophenoxytetraphenoxycyclotetraphosphazene, hexacyanophenoxydiphenoxycyclotetraphosphazene, and heptacyanophenoxymonophenoxycyclotetraphosphazene; the linear phosphazene compound is selected from polydiphenoxyphosphazene. The intrinsic viscosity of the polyphenylene ether measured by an Ubbelohde viscometer in chloroform at 25°C is 0.3 - 0.6 dl.

[0012] By weight, it may further include 0 - 0.3 parts of antioxidant, and the antioxidant is selected from at least one of pentaerythritol ester antioxidants and phosphite antioxidants. The pentaerythritol ester antioxidant can be pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (it can be Iragnox 1010), and the phosphite antioxidant is selected from phosphite (it can be Iragnox 168).

[0013] The preparation method of the polyphenylene ether composite material of the present invention comprises the following components: according to the ratio, mix each component evenly, and then extrude and pelletize through a twin-screw extruder. The temperature range of the screw is 260 - 300 °C, and the rotation speed range is 250 - 450 revolutions per minute to obtain the polyphenylene ether composite material.

[0014] The application of the polyphenylene ether composite material of the present invention is used for preparing the shell of an electronic device.

[0015] Alkali metal or alkaline earth metal hypophosphite is used to inhibit the change in melt index during the processing of polyphenylene ether at 280 °C - 325 °C. By weight, it includes 50 - 80 parts of polyphenylene ether, 0 - 20 parts of flame retardant, and alkali metal or alkaline earth metal hypophosphite; wherein, based on the total weight of the polyphenylene ether composite material, the P element content from the alkali metal or alkaline earth metal hypophosphite is 1000 - 3000 ppm.

[0016] The present invention has the following beneficial effects:

[0017] The present invention uses a specific content of alkali metal or alkaline earth metal hypophosphite (based on the total weight of the polyphenylene ether composite material, the P element content from the alkali metal or alkaline earth metal hypophosphite is 1000 - 3000 ppm) to partially or completely replace the traditional phosphite antioxidant, thioester antioxidant, hindered phenol antioxidant, and amine antioxidant, which can significantly improve the irregular decrease in melt index caused by the rearrangement of polyphenylene ether during the high-temperature melting process, improve the high-temperature injection molding processing stability (high-temperature heat retention stability), and further improve the processing injection molding appearance defects such as flow marks. Especially when the flame retardant is a polyphosphazene flame retardant, the effect is more significant. Description of the Drawings

[0018] Figure 1 : Comparison diagram of flow mark defects on the surface of the rear panel after injection molding. From left to right, there are no flow marks, slight flow marks, and obvious flow marks. If the flow mark defect on the surface of the rear panel is more serious than that of rear panel 3, it is a serious flow mark. Detailed Embodiments

[0019] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0020] The raw material sources are as follows:

[0021] Polyphenylene ether: PPE LXR040, with an intrinsic viscosity of 0.4 dl (25 °C);

[0022] Flame Retardant A: Hexaphenoxycyclotriphosphazene, SPB100, CAS: 1184-10-7, Otsuka Pharmaceutical Co., Ltd., Japan;

[0023] Flame Retardant B: Polydiphenoxyphosphazene, CAS: 28212-48-8, Benxi Jikai Technology Co., Ltd.;

[0024] Flame Retardant C: RDP, Resorcinol bis(diphenyl phosphate): CAS: 125997-21-9, Wansheng Technology Co., Ltd.;

[0025] Flame Retardant D: TPP, Triphenyl phosphate: CAS: 115-86-6, Wansheng Technology Co., Ltd.

[0026] Flame Retardant E: Bisphenol A bis(diphenyl phosphate), CAS: 5945-33-5, Wansheng Technology Co., Ltd.;

[0027] Sodium hypophosphite: CAS: 10039-56-2, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0028] Calcium hypophosphite: CAS: 7789-79-9, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0029] Preparation method of polyphenylene ether composite materials in examples and comparative examples: According to the ratio, mix each component evenly, and then extrude and pelletize through a twin-screw extruder. The temperature range of the screw is 260 - 300 °C, and the rotation speed range is 250 - 450 revolutions per minute to obtain polyphenylene ether composite materials.

[0030] Each test method:

[0031] (1) Thermal retention stability (300 °C, 4 min, 10 min) is tested according to the standard ISO1133-1:2011. The melt stays in the melt indexer at 300 °C for 4 min and 10 min respectively, and then a 5 kg weight is applied to extrude, and the melt index under the corresponding conditions is measured. The difference between the melt indices at 10 min and 4 min (10 min value - 4 min value) is preferably between +0.1 and 2.5 g / 10 min, and +0.5 - 1.5 g / 10 min is preferably selected from the perspective of injection molding quality.

[0032] (2) Appearance: Inject the polyphenylene ether composite material into a square plate of 100*100*2 mm, and observe whether there are appearance defects such as flow marks on the surface (as shown in the attached Figure 1 )

[0033] Table 1: Component contents (parts by weight) and test results of polyphenylene ether composite materials in Examples 1 - 6

[0034] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyphenylene Oxide 60 60 60 60 60 60 Flame Retardant A 10 Flame Retardant B 10 Flame Retardant C 10 Flame Retardant D 10 Flame Retardant E 10 Sodium Hypophosphite 0.17 0.21 0.21 0.21 0.21 0.21 P Element Content from Alkali Metal or Alkaline Earth Metal Hypophosphates 1000 1000 1000 1000 1000 1000 Thermal Retention Stability, 4 min, g / 10 min 3.1 11.76 12.06 11.86 11.18 12.37 Thermal Retention Stability, 10 min, g / 10 min 3.3 12.50 12.68 12.23 11.25 12.51 Thermal Retention Stability Difference, g / 10 min +0.2 +0.74 +0.62 +0.37 +0.07 +0.14 Appearance Slight Flow Marks No Flow Marks No Flow Marks Slight Flow Marks Slight Flow Marks Slight Flow Marks

[0035] As can be seen from Examples 2-6 and Comparative Examples 3 / 4 / 5, the influence of phosphazene flame retardants by sodium hypophosphite is more significant than that of other phosphate flame retardants or when no flame retardant is added.

[0036] Table 2: Component contents (parts by weight) and test results of polyphenylene ether composites in Examples 7-13

[0037] Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Polyphenylene Oxide 60 60 80 60 60 60 60 Flame Retardant C 10 5 10 10 10 10 10 Sodium Hypophosphite 0.30 0.40 0.35 0.38 0.41 0.62 Calcium Hypophosphite 0.34 P Element Content from Alkali Metal or Alkaline Earth Metal Hypophosphates 1500 1500 1550 1750 1900 2000 3000 Thermal Retention Stability, 4 min, g / 10 min 11.51 21.2 11.80 11.88 12.05 12.07 12.35 Thermal Retention Stability, 10 min, g / 10 min 12.34 21.6 12.72 12.86 13.11 13.03 12.68 Thermal Retention Stability Difference, g / 10 min +0.63 +0.4 +0.92 +0.98 +1.06 +0.96 +0.33 Appearance No Flow Marks No Flow Marks No Flow Marks No Flow Marks No Flow Marks No Flow Marks Slight Flow Marks

[0038] As can be seen from Examples 4 / 7 / 10-13, preferably based on the total weight of the polyphenylene ether composite, the P element content from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1500-2000 ppm, which has a more obvious inhibitory effect on the rearrangement of polyphenylene ether and better appearance.

[0039] Table 3: Component contents (parts by weight) and test results of polyphenylene ether composites in comparative examples

[0040] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polyphenylene Oxide 60 60 60 60 60 Flame Retardant A 10 10 10 - - Flame Retardant D 10 Sodium Hypophosphite 0.10 0.72 - - - P Element Content from Alkali Metal or Alkaline Earth Metal Hypophosphates 500 3500 - - - Thermal Retention Stability, 4 min, g / 10 min 11.1 12.9 16.7 3.5 15.2 Thermal Retention Stability, 10 min, g / 10 min 9.5 11.6 13.9 1.2 13.5 Thermal Retention Stability Difference, g / 10 min -1.60 -1.30 -2.80 -2.3 -1.7 Appearance Slight Flow Marks Severe Flow Marks Severe Flow Marks Severe Flow Marks Severe Flow Marks

[0041] As can be seen from Comparative Example 1, if the addition amount of sodium hypophosphite is too low, the inhibitory effect on the rearrangement reaction of polyphenylene ether during the high-temperature melting process is not significant.

[0042] As can be seen from Comparative Example 2, if the addition amount of sodium hypophosphite is too high, it is also easy to cause the appearance of flow marks.

Claims

1. A polyphenylene ether composite material, characterized in that, By weight, it includes 50 - 80 parts of polyphenylene ether, 0 - 20 parts of flame retardant, alkali metal hypophosphite and / or alkaline earth metal hypophosphite; wherein, based on the total weight of the polyphenylene ether composite material, the content of P element from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1000 - 3000 ppm.

2. The polyphenylene ether composite material according to claim 1, wherein, The alkali metal hypophosphite and / or alkaline earth metal hypophosphite is selected from at least one of sodium hypophosphite and calcium hypophosphite.

3. The polyphenylene ether composite material according to claim 1, wherein Based on the total weight of the polyphenylene ether composite material, the content of P element from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1500 - 2000 ppm.

4. The polyphenylene ether composite material according to claim 1, wherein, The flame retardant is selected from polyphosphazene flame retardants.

5. The polyphenylene ether composite material according to claim 4, characterized in that, The polyphosphazene flame retardant is selected from at least one of cyclotriphosphazene compounds, cyclotetraphosphazene compounds, cyclopentaphosphazene compounds, and linear phosphazene compounds; the cyclotriphosphazene compounds are selected from at least one of hexaphenoxycyclotriphosphazene, monocyanophenoxypentaphenoxycyclotriphosphazene, dicyanophenoxytetraphenoxycyclotriphosphazene, tricyanophenoxytriphenoxycyclotriphosphazene, tetracyanophenoxydiphenoxycyclotriphosphazene, and pentacyanophenoxymonophenoxycyclotriphosphazene; the cyclotetraphosphazene compounds are selected from at least one of monocyanophenoxyheptaphenoxycyclotetraphosphazene, dicyanophenoxyhexaphenoxycyclotetraphosphazene, tricyanophenoxypentaphenoxycyclotetraphosphazene, tetracyanophenoxytetraphenoxycyclotetraphosphazene, hexacyanophenoxydiphenoxycyclotetraphosphazene, and heptacyanophenoxymonophenoxycyclotetraphosphazene; the linear phosphazene compound is selected from polydiphenoxyphosphazene.

6. The polyphenylene ether composite material according to claim 1, wherein The polyphenylene ether has an intrinsic viscosity of 0.3 - 0.6 dl measured by an Ubbelohde viscometer in chloroform at 25°C.

7. The polyphenylene ether composite material according to claim 1, wherein By weight, it further includes 0 - 0.3 parts of antioxidant, and the antioxidant is selected from at least one of pentaerythritol ester antioxidants and phosphite antioxidants.

8. The preparation method of the polyphenylene ether composite material according to any one of claims 1-7, characterized in that, It includes the following components: according to the ratio, mix each component evenly, and then extrude and pelletize through a twin-screw extruder. The temperature range of the screw is 260 - 300°C, and the rotation speed range is 250 - 450 revolutions per minute to obtain the polyphenylene ether composite material.

9. Use of the polyphenylene ether composite material according to any one of claims 1-7, characterized in that, It is used for preparing the housing of electronic equipment.

10. Alkali metal or alkaline earth metal hypophosphite is used to inhibit the change in melt index during the processing of polyphenylene ether at 280°C - 325°C, characterized in that, By weight, it includes 50 - 80 parts of polyphenylene ether, 0 - 20 parts of flame retardant, alkali metal hypophosphite and / or alkaline earth metal hypophosphite; wherein, based on the total weight of the polyphenylene ether composite material, the content of P element from alkali metal hypophosphite and / or alkaline earth metal hypophosphite is 1000 - 3000 ppm.

Images