A kind of shrinkage-resistant polyphenylene ether composition and its preparation method and application

Abstract

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

Description

Technical Field

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

[0002] As an amorphous engineering plastic, polyphenylene ether (PPE) has excellent flame retardancy, acid and alkali resistance, high temperature resistance, moisture and heat resistance, and dimensional stability. It can perfectly meet the material selection requirements of automotive electronics. It is widely used in automotive electronics as a raw material for battery trays, insulation boards, battery housings and other parts. However, in the application process of automotive electronic materials, many thick-walled parts are involved. When the wall thickness reaches more than 4mm, the injection molded parts are prone to post-shrinkage during the cooling process, and there are obvious shrinkage marks, which greatly affects the flatness and performance of the parts. At present, the industry mainly improves the anti-shrinkage performance of the material by adding fillers and glass fibers to polyphenylene ether, but the effect is very limited, and it fails to effectively solve the shrinkage problem of injection molded parts, and it will deteriorate the toughness of the material, limiting the application of PPE materials. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention aims 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] Polystyrene resin 5-25 parts;

[0009] 1-4 parts of toughening agent;

[0010] 0.1-2 parts of foaming agent;

[0011] Glass fiber 0-30 parts;

[0012] Antioxidant 0-1 part;

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

[0014] The invention adds a certain amount of polystyrene resin to the polyphenylene ether resin, which can effectively reduce the post-shrinkage of the injection molded part during the cooling process. Too high a PS content will lead to a decrease in the glass transition temperature of the material, which will make the shrinkage mark more obvious. 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 simplicity, the present invention will no longer exhaustively list the specific values ​​included in the range.

[0016] The weight proportions 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 values ​​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 melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 5-90g / 10min; more preferably, the melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 10-60g / 10min; further preferably, the melt flow rate of the polyphenylene ether resin at 315°C and 10kg is 20-40g / 10min; the melt flow rate of the polyphenylene ether resin is tested with reference to standard ISO 1133-1-2011. The present invention selects a polyphenylene ether resin with a certain melt flow rate, 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 to reduce 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, azobisisoheptylnitrile or azodiphenylamine; the expandable microspheres are preferably expandable microsphere masterbatches 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, cresol diphenyl phosphate, dicresol phenyl phosphate, dimethyl ethyl phosphate, methyl dibutyl phosphate, ethyl dipropyl phosphate, hydroxyphenyl diphenyl phosphate, tetraphenyl (bisphenol-A) diphosphate, tetraphenyl resorcinol diphosphate; the phosphate is selected from at least one of diammonium hydrogen phosphate, diammonium dihydrogen phosphate, melamine, pyrophosphate melamine, orthophosphate melamine, phosphoric acid amide, polyphosphate melamine, ammonium polyphosphate or polyphosphoric acid amide. The present invention selects a specific flame retardant to be added, which can obtain excellent flame retardant properties without 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: according to the ratio, the components except the foaming agent and the glass fiber are put into a high-speed mixer and dispersed evenly, and then enter 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 250-500rpm; 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 a shrinkage-resistant polyphenylene ether composition.

[0028] The present invention also provides the use of the above-mentioned shrinkage-resistant polyphenylene ether composition in automotive electronic parts, which are 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 the 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 Schematic diagram of the sample mold for anti-sink mark performance test. Implementation

[0032] The present invention is described in detail below in conjunction with 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 of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

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

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

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

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

[0037] Polyphenylene ether resin 4: melt index of 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, Secco;

[0040] Flame retardant: tetraphenylresorcinol diphosphate, Wansheng;

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

[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, Crestrix

[0046] Blowing agent 3: azo blowing agent, azodicarbonamide AC, Shanghai Yien Chemical;

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

[0048] Antioxidant: Antioxidant 1010 and antioxidant 168 are compounded in a weight ratio of 1:2 and are commercially available. The same antioxidant is 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, the components except the glass fiber are put into a high-speed mixer and dispersed evenly, and then enter 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 a shrinkage-resistant polyphenylene ether composition; wherein the screw speed is 350 rpm; 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: Figure 1 The mold schematic diagram shown (the length, width and height of the rectangle are 100*57*6mm) is used to inject the material at 300℃, 50MPa pressure and 50% injection speed. The thickness difference between the middle position (b1) and both sides (A1) of the thick wall of the injection molded part is tested for evaluation. The larger the thickness difference, the worse the material's resistance to shrinkage marks.

[0053] (2) Notched impact strength: Prepare A-notch standard samples that meet the specifications in accordance with ISO 180-2019 and perform tests 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]

[0056] Continued from Table 1:

[0057]

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

[0059]

[0060] It can be seen from the above results that the present invention prepares a polyphenylene ether composition with excellent anti-sink mark effect by selecting a polyphenylene ether resin with a specific melt flow rate and adding a certain proportion of polystyrene resin and foaming agent, which can significantly reduce the post-shrinkage of the injection molded part 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 the high toughness of the material (impact strength ≥9 KJ / m 2 ).

[0061] In Comparative Example 1, no polystyrene resin is added, and the material has poor anti-sinking performance and poor toughness.

[0062] 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 high impact strength of the material.

[0064] In Comparative Example 4, excessive addition of foaming agent leads to poor anti-sinking performance 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 10 kg is 5-90 g / 10 min.

3. The shrinkage-resistant polyphenylene ether composition according to claim 2, characterized in that: The melt flow rate of the polyphenylene ether resin at 315° C. and 10 kg is 10-60 g / 10 min.

4. The shrinkage-resistant polyphenylene ether composition according to claim 3, characterized in that: The melt flow rate of the polyphenylene ether resin at 315° C. and 10 kg is 20-40 g / 10 min.

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

6. 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.

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

8. 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.

9. 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.

10. The shrinkage-resistant polyphenylene ether composition according to claim 9, characterized in that: 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.

11. The shrinkage-resistant polyphenylene ether composition according to claim 10, characterized in that: The styrenic block copolymer is selected from styrene-ethylene / butylene-styrene block copolymers.

12. The shrinkage-resistant polyphenylene ether composition according to claim 1, characterized in that: The diameter of the glass fiber is 8-12 μm; 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.

13. 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.

14. The method for preparing the shrinkage-resistant polyphenylene ether composition according to any one of claims 1 to 13, 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.

15. Use of the shrinkage-resistant polyphenylene ether composition according to any one of claims 1 to 13 in automotive electronic parts.

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