Shrinkage-resistant polyphenylene ether composition, preparation method therefor and use thereof

Abstract

Disclosed is a shrinkage-resistant polyphenylene ether composition, comprising the following components in parts by weight: 40-70 parts of a polyphenylene ether resin, 5-25 parts of a polystyrene resin, 1-4 parts of a toughening agent, 0.1-2 parts of a foaming agent, 0-30 parts of glass fiber, and 0-1 parts of an antioxidant; the weight ratio of the polyphenylene ether resin to the polystyrene resin is 2-14. The present invention prepares a polyphenylene ether composition having excellent anti-shrinkage effects by means of adding a specific proportion of polystyrene resin and foaming agent to a polyphenylene ether resin, which can significantly reduce post-shrinkage of injection molded parts during a cooling process and ensure relatively high toughness of a material, and is particularly suitable for thick-walled parts in the field of automotive electronics.

Description

A shrinkage-resistant polyphenylene ether composition and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a shrinkage-resistant polyphenylene ether composition, a preparation method and an application thereof. Background Art

[0002] Polyphenylene ether (PPE), an amorphous engineering plastic, offers excellent flame retardancy, acid and alkali resistance, high temperature resistance, humidity and heat resistance, and dimensional stability. It perfectly meets the material selection requirements for automotive electronics and is widely used in automotive electronics as a raw material for components such as battery trays, insulation boards, and battery casings. However, the application of automotive electronic materials involves many thick-walled parts. When the wall thickness exceeds 4mm, injection molded parts are prone to post-shrinkage during cooling, resulting in significant sink marks, which significantly affect the part's flatness and performance. Currently, the industry primarily aims to improve the material's sink mark resistance by adding fillers and glass fiber to polyphenylene ether, but the results are very limited and fail to effectively address the sink mark problem in injection molded parts. Furthermore, this can degrade the material's toughness, limiting the application of PPE materials. Summary of the Invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a shrinkage-resistant polyphenylene ether composition, which effectively solves the shrinkage problem of thick-walled injection molded parts and can ensure high toughness of the material.

[0004] Another object of the present invention is to provide a method for preparing the above-mentioned shrinkage-resistant polyphenylene ether composition.

[0005] The present invention is achieved through the following technical solutions:

[0006] A shrinkage-resistant polyphenylene ether composition comprises the following components by weight:

[0007] 40-70 parts of polyphenylene ether resin;

[0008] 5-25 parts of polystyrene resin;

[0009] 1-4 parts of toughening agent;

[0010] 0.1-2 parts of foaming agent;

[0011] Glass fiber 0-30 parts;

[0012] 0-1 part antioxidant;

[0013] The weight ratio of the polyphenylene ether resin to the polystyrene resin is 2-14.

[0014] The present invention effectively reduces post-shrinkage during the cooling process of injection-molded parts by adding a certain amount of polystyrene resin to the polyphenylene ether resin. Excessive PS content can lower the material's glass transition temperature, leading to more pronounced sink marks. Preferably, the weight ratio of the polyphenylene ether resin to the polystyrene resin is 2.5-8, more preferably 3-6.

[0015] The polystyrene resin of the present invention is preferably high-impact polystyrene. The weight percentage of the polystyrene resin can be 5 parts, 8 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, or 20 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively enumerate the specific values ​​included in the above ranges.

[0016] The weight percentage of the polyphenylene ether resin can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0017] The mass content of the polyphenylene ether resin in the shrinkage-resistant polyphenylene ether composition of the present invention is more than 45%.

[0018] Preferably, the polyphenylene ether resin has a melt flow rate of 5-90 g / 10 min at 315° C. and 10 kg; more preferably, the melt flow rate of the polyphenylene ether resin at 315° C. and 10 kg is 10-60 g / 10 min; further preferably, the melt flow rate of the polyphenylene ether resin at 315° C. and 10 kg is 20-40 g / 10 min; the melt flow rate of the polyphenylene ether resin is tested in accordance with ISO 1133-1-2011. By selecting a polyphenylene ether resin with a certain melt flow rate, the present invention adjusts the fluidity of the material, further reduces the pressure loss of the material during the injection molding process, and makes the injection molded part have a more compact structure, thereby reducing shrinkage.

[0019] The present invention also introduces a certain amount of foaming agent to form a microporous structure in the injection molded part, further reducing its post-shrinkage during the cooling process. Preferably, the weight percentage of the foaming agent is 0.5-1.5 parts.

[0020] The mass content of the foaming agent in the shrinkage-resistant polyphenylene ether composition of the present invention is 0.1wt% to 2.5wt%.

[0021] Preferably, the foaming agent is selected from any one or more of carbonate foaming agents, azo foaming agents and expandable microspheres; further, the carbonate foaming agent can be selected from any one or more of sodium bicarbonate foaming agents; the azo foaming agent can be selected from any one or more of azodicarbonamide, azobisisobutyronitrile, azobisisoheptanenitrile or azoaminobenzene; the expandable microspheres are preferably expandable microsphere masterbatch with an average microsphere diameter of 20-120 μm and a foaming temperature between 180-260°C.

[0022] Preferably, the glass fiber has a diameter of 8-12 μm; more preferably, it is any one or more of the coupling agent-modified glass fibers.

[0023] Preferably, the antioxidant is selected from any one or more of phenolic antioxidants, phosphite antioxidants or metal passivators.

[0024] According to the flame retardant performance requirements of the material, the shrinkage-resistant polyphenylene ether composition of the present invention further includes 6-15 parts of flame retardant by weight. Preferably, the flame retardant is selected from at least one of phosphate compounds or phosphates; the phosphate compound is selected from at least one of trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresol phosphate, trixyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, dimethyl ethyl phosphate, methyl dibutyl phosphate, ethyl dipropyl phosphate, hydroxyphenyl diphenyl phosphate, tetraphenyl (bisphenol-A) diphosphate, and tetraphenylresorcinol diphosphate; the phosphate is selected from at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, melamine, melamine pyrophosphate, melamine orthophosphate, phosphoric acid amide, polyphosphate melamine, ammonium polyphosphate, or polyphosphoric acid amide. The present invention selects a specific flame retardant to be added, which can achieve excellent flame retardant properties while not affecting the anti-sinking effect of the material.

[0025] Preferably, the toughening agent is selected from any one or more of styrene block copolymers; further, the styrene block copolymer is preferably selected from any one or more of styrene-butadiene-styrene block copolymer, styrene-ethylene / butylene-styrene block copolymer or styrene-ethylene / propylene-styrene block copolymer, more preferably styrene-ethylene / butylene-styrene block copolymer.

[0026] The present invention also provides a method for preparing the above-mentioned shrinkage-resistant polyphenylene ether composition, comprising the following steps: adding all components except a foaming agent and glass fiber into a high-speed mixer according to a proportion and dispersing them uniformly, then feeding the components into a twin-screw extruder with glass fiber side-feeding, extruding and granulating the components, and then externally mixing the foaming agent to obtain the shrinkage-resistant polyphenylene ether composition; wherein the screw speed is 250-500 rpm; and the extrusion temperature is 230-290°C.

[0027] When a foaming agent with a foaming temperature higher than the extrusion temperature is used, the foaming agent can be directly added to the components for blending, extrusion and granulation to obtain the shrinkage-resistant polyphenylene ether composition.

[0028] The present invention also provides the application of the above-mentioned shrinkage-resistant polyphenylene ether composition in automotive electronic parts, which is specifically suitable for thick-walled parts with a wall thickness of ≥4 mm, such as new energy vehicle battery transfer trays, battery brackets, etc.

[0029] The present invention has the following beneficial effects:

[0030] The present invention prepares a polyphenylene ether composition with excellent anti-sink mark effect by adding a certain proportion of polystyrene resin and foaming agent to polyphenylene ether resin, which can significantly reduce the post-shrinkage of injection molded parts during the cooling process and ensure high toughness of the material (impact strength ≥9 KJ / m 2 ), especially suitable for thick-walled parts in the automotive electronics field. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the sample mold for the anti-sink mark performance test. DETAILED DESCRIPTION

[0032] 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 are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0033] The raw materials used in the examples and comparative examples of the present invention are described below, but are not limited to these materials:

[0034] Polyphenylene ether resin 1: melt index 35 g / 10 min at 315°C and 10 kg, PPE LXR040, Bluestar;

[0035] Polyphenylene ether resin 2: melt index of 14 g / 10 min at 315°C and 10 kg, PPE LXR045, Bluestar;

[0036] Polyphenylene ether resin 3: melt index of 53 g / 10 min at 315°C and 10 kg, PPELXR035, Bluestar;

[0037] Polyphenylene ether resin 4: melt index 7 g / 10 min at 315°C and 10 kg, PPE LXR050, Bluestar;

[0038] Polystyrene resin 1: high impact polystyrene, PS MA5210, Astor;

[0039] Polystyrene resin 2: polystyrene, GPPS 123P, Seco;

[0040] Flame retardant: tetraphenylresorcinol diphosphate, Wansheng;

[0041] Toughener 1: Styrene-ethylene / butylene-styrene block copolymer; SEBS 6151, Formosa Plastics Corporation;

[0042] Toughener 2: Styrene-butadiene-styrene block copolymer, SBS1401, Sinopec

[0043] Toughener 3: Styrene-ethylene / propylene-styrene block copolymer, G1702, Kraton

[0044] Foaming agent 1: carbonate foaming agent, F-88, Yonghe;

[0045] Foaming agent 2: Expanded microsphere foaming agent, DU2601, Cresray

[0046] Foaming agent 3: azo foaming agent, azodicarbonamide AC, Shanghai Yien Chemical;

[0047] Glass fiber: diameter 8-12 μm, silane modified glass fiber, boulder;

[0048] Antioxidant: Antioxidant 1010 and antioxidant 168 were compounded in a weight ratio of 1:2 and purchased from the market. The same antioxidant was used in both the examples of the present invention and the comparative examples.

[0049] Preparation method of polyphenylene ether composition of embodiment and comparative example:

[0050] According to the ratio, all components except glass fiber are put into a high-speed mixer and dispersed evenly, and then enter a twin-screw extruder with glass fiber side-feed. After extrusion and granulation, the foaming agent is evenly mixed by external mixing to obtain a shrinkage-resistant polyphenylene ether composition; wherein the screw speed is 350 rpm; and the barrel temperature is set to 265°C, 275°C, 260°C, and 250°C.

[0051] Related performance test methods:

[0052] (1) Evaluation of anti-sink mark performance: According to the mold schematic diagram shown in Figure 1 (the length, width and height of the rectangular position are 100*57*6mm), the material is injected at 300℃, 50MPa pressure and 50% injection speed. The evaluation is carried out by testing the thickness difference between the middle position (b1) and the two sides (A1) of the thick wall of the injection molded part. The larger the thickness difference, the worse the material's anti-sink mark performance.

[0053] (2) Notched impact strength: Prepare A-type notched standard samples that meet the specifications in accordance with ISO 180-2019 and test them in accordance with the standard.

[0054] Table 1: Distribution ratios of each group in Examples 1-13 (by weight) and related performance test results

[0055] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyphenylene ether resin 16050706060 Polyphenylene ether resin 260 Polyphenylene ether resin 3 Polyphenylene ether resin 4 Polystyrene resin 115255151515 Polystyrene resin 2 Flame retardant 101010101010 Toughening agent 1222222 Toughening agent 2 Toughening agent 3 Foaming agent 11110.221 Foaming agent 2 Foaming agent 3 Glass fiber 151515151515 Antioxidant 0.50.50.50.50.50.5 Thickness difference (mm) 0.010.050.030.060.010.07 Izod notched impact strength (KJ / m 2 )13131113913

[0056] Continued from Table 1:

[0057] Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Polyphenylene ether resin 16060604065 Polyphenylene ether resin 2 Polyphenylene ether resin 360 Polyphenylene ether resin 460 Polystyrene resin 115151515520 Polystyrene resin 215 Flame retardant 1010101010 / 14 Toughening agent 12221.54 Toughening agent 22 Toughening agent 32 Foaming agent 111111 Foaming agent 20.5 Foaming agent 31.5 Glass fiber 151515151510 / Antioxidant 0.50.50.50.50.50.5 / Thickness difference (mm) 0.080.100.030.030.030.020.04 Izod notched impact strength (KJ / m 2 )1213911101221

[0058] Table 2: Distribution ratio of each group in comparative examples 1-4 (by weight) and related performance test results

[0059] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Polyphenylene ether resin 175406060 Polystyrene resin 1 / 351515 Flame retardant 10101010 Toughening agent 12222 Foaming agent 111 / 4 Glass fiber 15151515 Antioxidant 0.50.50.50.5 Thickness difference (mm) 0.120.180.250.27 Izod notched impact strength (KJ / m 2 )810146

[0060] The above results show that the present invention selects a polyphenylene ether resin with a specific melt flow rate and adds a certain proportion of polystyrene resin and foaming agent to prepare a polyphenylene ether composition with excellent anti-sink mark effect. It can significantly reduce the post-shrinkage of injection molded parts during the cooling process (the thickness difference between the middle position (b1) and the two sides (A1) of the thick wall of the injection molded part is ≤0.1mm), and can ensure high toughness of the material (impact strength ≥9 KJ / m 2 ).

[0061] In Comparative Example 1, no polystyrene resin was added, and the material had poor shrinkage resistance and poor toughness.

[0062] In Comparative Example 2, the polystyrene resin content is too high, which will lead to a decrease in the glass transition temperature of the material and make the shrinkage mark obvious.

[0063] Comparison of Comparative Example 3 with Examples 1 / 4 / 5 shows that the addition of a certain amount of foaming agent in the present invention can effectively improve the anti-sinking performance of the material and ensure a higher impact strength of the material.

[0064] In Comparative Example 4, excessive addition of foaming agent leads to poor shrinkage resistance of the material and significant degradation of toughness.

Claims

1. A shrinkage-resistant polyphenylene ether composition, characterized in that: By weight, it contains the following components: 40-70 parts of polyphenylene ether resin; Polystyrene resin 5-25 parts; 1-4 parts of toughening agent; 0.1-2 parts of foaming agent; Glass fiber 0-30 parts; Antioxidant 0-1 part; The weight ratio of the polyphenylene ether resin to the polystyrene resin is 2-14.

2. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 5-90g / 10min; preferably, the melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 10-60g / 10min; more preferably, the melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 20-40g / 10min.

3. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The polystyrene resin is selected from high impact polystyrene.

4. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The weight ratio of the polyphenylene ether resin to the polystyrene resin is 2.5-8, preferably 3-6.

5. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The foaming agent is selected from any one or more of carbonate foaming agents, azo foaming agents and expandable microspheres; the carbonate foaming agent is selected from any one or more of sodium bicarbonate foaming agents; the azo foaming agent is selected from any one or more of azodicarbonamide, azobisisobutyronitrile, azobisisoheptylnitrile or azoaminobenzene; the expandable microspheres are selected from expandable microsphere masterbatches with an average microsphere diameter of 20-120 μm and a foaming temperature between 180-260°C.

6. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The toughening agent is selected from any one or more of styrene block copolymers; preferably, the styrene block copolymer is selected from any one or more of styrene-butadiene-styrene block copolymer, styrene-ethylene / butylene-styrene block copolymer or styrene-ethylene / propylene-styrene block copolymer; more preferably, the styrene block copolymer is selected from styrene-ethylene / butylene-styrene block copolymer.

7. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The diameter of the glass fiber is 8-12 μm; preferably, the glass fiber is selected from any one or more of coupling agent modified glass fibers; the antioxidant is selected from any one or more of phenolic antioxidants, phosphite antioxidants or metal passivators.

8. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: By weight, the invention also includes 6-15 parts of flame retardant; the flame retardant is selected from at least one of phosphate compounds or phosphates; the phosphate compound is selected from at least one of trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, trixyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, dimethyl ethyl phosphate, methyl dibutyl phosphate, ethyl dipropyl phosphate, hydroxyphenyl diphenyl phosphate, tetraphenyl (bisphenol-A) diphosphate, and tetraphenylresorcinol diphosphate; the phosphate is selected from at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, melamine, melamine pyrophosphate, melamine orthophosphate, phosphoric acid amide, polyphosphate melamine, ammonium polyphosphate, or polyphosphoric acid amide.

9. The method for preparing the shrinkage-resistant polyphenylene ether composition according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: according to the proportion, the components except the foaming agent and the glass fiber are put into a high-speed mixer and dispersed evenly, and then the components are put into a twin-screw extruder, the glass fiber is fed sideways, and after extrusion granulation, the foaming agent is mixed evenly by external mixing to obtain the shrinkage-resistant polyphenylene ether composition; wherein the screw speed is 250-500 rpm; and the extrusion temperature is 230-290°C.

10. Use of the shrinkage-resistant polyphenylene ether composition according to any one of claims 1 to 8 in automotive electronic parts.

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