CN112679956A

CN112679956A - High-precision low-overflow low-warpage low-dielectric PPS modified material and preparation method thereof

Info

Publication number: CN112679956A
Application number: CN202011524031.9A
Authority: CN
Inventors: 张小林; 杨秋会; 何任畅; 贺鹏勇
Original assignee: Dongguan Huaying New Material Co ltd
Current assignee: Dongguan Huaying New Material Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-04-20

Abstract

The invention discloses a high-precision low-overflow low-warpage low-dielectric PPS modified material and a preparation method thereof, wherein the modified material comprises, by weight, 19.6-44.2% of PPS, 5-11% of PPE, 30-45% of glass fibers, 4-7% of minerals (I), 5-20% of minerals (II), 2-5% of toughening agents, 0.3-0.45% of lubricants, 0.15-0.3% of antioxidants, 0.2-0.35% of halogen absorbents and 0.15-0.3% of sulfur removing agents, wherein the minerals (I) are selected from inorganic salt whisker materials, and the minerals (II) are selected from hollow microspheres. The PPS modified material provided by the invention has the characteristics of high strength, high dimensional accuracy, low warpage, low overflow, chemical resistance, good heat resistance effect, good flame retardant effect, relatively low dielectric constant and the like, and can be applied to 5G related scenes such as indoor small base stations, CPE shells and the like.

Description

High-precision low-overflow low-warpage low-dielectric PPS modified material and preparation method thereof

Technical Field

The invention relates to the technical field of polyphenylene sulfide materials, and particularly relates to a high-precision low-overflow low-warpage low-dielectric PPS modified material and a preparation method thereof.

Background

The 5G network is a fifth generation mobile communication network, the peak theoretical transmission speed of which can reach 1Gb per second, which is hundreds of times faster than that of the 4G network, and with the advent of the 5G technology, the era of sharing 3D movies, games, and Ultra High Definition (UHD) programs with intelligent terminals is moving forward. With the advent of the 5G era, related applications of 5G have been closely related to human life, and research on the application of 5G-related materials is also a piece of fire heat.

PPS (polyphenylene sulfide) is a crystalline thermoplastic engineering plastic, and has the advantages of higher heat distortion temperature (up to 260 ℃), almost unchanged dimensional stability under high temperature and high humidity, chemical resistance which is comparable to that of fluorine-containing resin, high mechanical strength, flame retardance which can reach over 44 limiting oxygen indexes without adding a flame retardant, and the like. PPS is typically used as an antenna element of a base station in 5G-related applications. PPS has excellent fluidity, but has the defects that flash is easily caused by mold overflow during product molding, subsequent processes are increased, warping is easily caused during demolding of pure glass fiber reinforced PPS modified materials, the dielectric constant is too high to meet the requirements of low dielectric materials, and the application of the PPS modified materials in certain scenes in the 5G market is limited.

Therefore, it is necessary to develop a PPS modified material with high precision, low overflow, low warpage and low dielectric to solve the above-mentioned drawbacks.

Disclosure of Invention

Aiming at the technical defects, the application aims to provide the high-precision low-overflow low-warpage low-dielectric PPS modified material, which avoids overflow of a mold and warpage, and has the characteristics of high strength, high heat resistance, chemical resistance, good flame retardant effect, low dielectric constant (good wave-transmitting performance) and the like.

In order to achieve the purpose, the invention provides a high-precision low-overflow low-warpage low-dielectric PPS modified material, which comprises the following components in percentage by weight:

wherein the mineral (I) is selected from inorganic salt whisker materials, and the mineral (II) is selected from cenospheres.

Correspondingly, the application also provides a preparation method of the high-precision low-overflow low-warpage low-dielectric PPS modified material, which comprises the following steps:

(1) weighing PPS, PPE, glass fiber, mineral (I), mineral (II), compatilizer, lubricant, antioxidant, halogen absorbent and desulfurizing agent according to the proportion;

(2) uniformly mixing PPS, PPE, mineral (I), a compatilizer, a lubricant, an antioxidant, a halogen absorbent and a desulfurizing agent to obtain a mixture A;

(3) adding the mixture A into a main feeding port of a double-screw extruder, adding glass fiber into a first side feeding port of the double-screw extruder, adding the mineral (II) into a second side feeding port of the double-screw extruder, and performing melt extrusion and granulation.

The process conditions are as follows: the length-diameter ratio of the double-screw extruder is 48:1, and the temperature of each heating area is respectively set as follows: the temperature of the first zone is 150-200 ℃, the temperature of the second zone is 280-310 ℃, the temperature of the third zone is 285-310 ℃, the temperature of the fourth zone is 290-320 ℃, the temperature of the fifth zone is 290-320 ℃, the temperature of the sixth zone is 290-320 ℃, the temperature of the seventh zone is 290-320 ℃, the temperature of the eighth zone is 290-320 ℃, the temperature of the ninth zone is 290-320 ℃, the temperature of the tenth zone is 285-310 ℃, the temperature of the eleventh zone is 285-310 ℃, the temperature of the twelfth zone. The rotating speed of the screw is 300-360 r/min; the vacuum degree is-0.03 to-0.06 Mpa.

Compared with the prior art, in the high-precision low-overflow low-warpage low-dielectric PPS modified material, in order to obtain the PPS modified material with low overflow modulus, a certain amount of PPE material with higher melt viscosity is added for improvement; by adding the glass fiber and the inorganic salt whisker material, the shrinkage rate of the PPS modified material is controlled and the difference between the longitudinal shrinkage rate and the transverse shrinkage rate of the PPS modified material is reduced, so that the PPS modified material with low warpage and high precision is obtained, particularly, the glass fiber and the inorganic salt whisker material play a synergistic effect, the internal stress of the material can be transmitted and dispersed more uniformly, the warpage phenomenon of the material caused by nonuniform stress and particularly after demolding is reduced, and the precision of the material is good; and adding the hollow microspheres to obtain the PPS modified material with lower dielectric property.

Drawings

FIG. 1 is a schematic structural diagram of a twin-screw extruder in the preparation method of the high-precision low-overflow low-warpage low-dielectric PPS modified material.

Description of the symbols:

a main feeding port 1, a first side feeding port 2, a second side feeding port 3 and a double-screw extruder 4

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The PPS modified material prepared by overcoming the defects of PPS has the characteristics of high strength, high heat resistance, chemical resistance, good flame retardant effect, low dielectric constant (good wave-transmitting performance) and the like, can be applied to indoor small base stations and CPE shells in the 5G market, has excellent flowability, low overflow modulus and low warpage, can be used for forming complex thin-wall products, and enables designers to have more design freedom degree to design products with more difference and competitiveness.

The PPS modified material with high precision, low overflow, low warpage and low dielectric constant comprises the following components in percentage by weight:

Wherein PPS (polyphenylene sulfide) can be selected from straight-chain or cross-linked materials, low-halogen or high-halogen, and its melt index is 50-200g/cm³The test conditions were 316 ℃/2.16 kg. Preferably, the PPS is a low-halogen linear PPS. Further, the PPS content may be, but is not limited to, 19.6%, 24%, 28%, 30%, 32%, 34%, 38%, 40%, 44.2%.

The melt viscosity of the PPE (poly (2, 6-dimethyl-1, 4-phenylene ether)) is high, so that the PPS modified material is not easy to overflow when a product is molded, burrs are reduced, and subsequent processing is omitted. Preferably, PPE materials having an intrinsic viscosity of 0.15 to 0.48dl/g are selected, more preferably PPE materials having an intrinsic viscosity of 0.15 to 0.33 dl/g. Further, the PPE content may be, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%.

Preferably, the glass fiber is low-dielectric constant continuous glass fiber or chopped fiber, preferably chopped fiber. Further, the shape of the glass fiber is selected from a cylindrical shape or a flat shape, and a flat shape is preferable. The material warps after demolding, mainly due to the difference in shrinkage in the Machine Direction (MD) and Transverse Direction (TD) and residual stress relaxation. And by adding the flat glass fibers into the PPS modified material, the flat glass fibers tend to slide rather than roll when the product is injection-molded, and the flat glass fibers tend to slide in a plane when the product is formed, so that more isotropic dispersion can be provided, the difference of the shrinkage rates of the material in the longitudinal direction (MD) and the Transverse Direction (TD) is reduced, and the warping is reduced. Further, in the flat glass fiber, the ratio of flatness (length: width) may be selected from, but not limited to, 3:1 or 4:1, preferably 4: 1. Further, the content of the glass fiber may be, but not limited to, 30%, 35%, 40%, 45%.

Preferably, the inorganic salt whisker material is at least one selected from calcium salt, aluminum salt, magnesium salt and potassium salt. Magnesium salt whiskers and calcium salt whiskers are preferred. Wherein, the diameter of the whisker is not limited to 0.1-2.0 μm, and the length is 2-100 μm. Further, the whisker shape may be fibrous or needle-like, preferably needle-like. The whisker is a single crystal fiber formed under special conditions, has high length-diameter ratio (L/D is more than 10), is highly ordered, and hardly has internal defects such as holes, dislocation, particle interfaces and the like in the interior, so the whisker has high strength and high modulus, can play a skeleton role when being added into glass fiber reinforced plastic, can more uniformly transmit and disperse the internal stress of the material, and reduces the warping phenomenon of the material caused by nonuniform stress. Further, the content of the inorganic salt whisker material can be, but is not limited to, 4%, 5%, 6%, 7%.

Preferably, the cenospheres are one or two of cenospheres of hollow glass and cenospheres of hollow mullite, preferably the cenospheres of hollow mullite. When the hollow glass beads pass through a double-screw extruder or are injection-molded products, the hollow glass beads are easy to break due to poor compression resistance, and the effect is not ideal and unstable. The mullite hollow microspheres are aluminosilicate in components, have higher strength and better pressure resistance than the hollow glass microspheres, can be better reserved during material preparation and product forming, have better and more stable effect, and obtain more stable low-dielectric PPS modified materials and products. Further, the average particle diameter of the cenospheres may be, but not limited to, 5 to 40 μm, preferably 15 to 30 μm. Further, the content of the cenospheres can be, but is not limited to, 5%, 8%, 11%, 14%, 17%, 20%.

Preferably, the compatilizer is at least one of epoxy resin, SEBS-g-MAH, PPO-g-MAH and PS, but not limited thereto. Further, the content of the compatibilizer may be, but not limited to, 2%, 3%, 4%, 5%.

Preferably, the lubricant is at least one of stearate, amide, silicone and wax. Amide and silicone based lubricants are preferred and may be, but are not limited to, TAF, silicone masterbatches, used alone or in a 1: 1-2 compounding. Further, the content of the lubricant may be, but not limited to, 0.3%, 0.35%, 0.4%, 0.45%.

Preferably, the antioxidant can be, but is not limited to, a compound of a hindered phenol antioxidant and a phosphite antioxidant, and is preferably prepared by compounding tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester (antioxidant 1010) and tris (2, 4-di-tert-butylphenyl) phosphite (antioxidant 168) according to a weight ratio of 1: 1-3. Further, the content of the antioxidant may be, but not limited to, 0.15%, 0.2%, 0.25%, 0.3%.

Preferably, the halogen absorbent is selected from at least one of calcium stearate, zinc stearate, and magnesium stearate. Preference is given to using calcium stearate and zinc stearate, alone or in a ratio of 1: 1-2 compounding. Further, the content of the halogen absorbent may be, but not limited to, 0.2%, 0.25%, 0.3%, 0.35%.

Preferably, the sulfur removing agent can be one or more of organic polyphosphonate, inorganic polyphosphate, hydroxycarboxylic acid and aminocarboxylic acid. Ferric ammonium citrate, an aminocarboxylic acid, is preferred. Since the PPS raw material is synthesized, sulfur molecules remain in the resin, or COS, CS are generated under the condition of high-temperature shearing₂And the like, and these gases are volatilized in the production process to generate pungent odor. In order to remove these elemental sulfur gases, elemental iron is used to combine with elemental sulfur at high temperatures to produce water-insoluble iron sulfides. Further, the content of the sulfur removing agent may be, but not limited to, 0.15%, 0.2%, 0.25%, 0.3%.

In order to realize the preparation of the high-precision low-overflow low-warpage low-dielectric PPS modified material, the application correspondingly provides a preparation method of the high-precision low-overflow low-warpage low-dielectric PPS modified material, which comprises the following steps:

(3) adding the mixture A into a main feeding port 1 (refer to figure 1) of a double-screw extruder 4, adding glass fiber into a first side feeding port 2 of the double-screw extruder 4, adding the mineral (II) into a second side feeding port 3 of the double-screw extruder 4, and performing melt extrusion and granulation.

Preferably, in the step (2), the mineral (I) is subjected to surface treatment and then to mixing operation, so as to increase compatibility and dispersibility in the resin, further reduce the warping phenomenon and improve the precision of the material, and the processing steps are as follows:

(1) preheating the mineral (I) in a stirrer at 60-100 deg.C for 10-20 min;

(2) adding a coupling agent into a stirrer to be mixed and stirred with the mineral (I), and controlling the temperature to be less than or equal to 100 ℃;

(3) and drying the stirred material for later use.

Preferably, the coupling agent is selected from at least one of silane coupling agent, titanate coupling agent, aluminate coupling agent, bimetallic coupling agent, lignin coupling agent and tin coupling agent. Preferably, an epoxy-containing coupling agent, such as KH560, is used.

Preferably, the process conditions of the twin-screw extruder are: the length-diameter ratio of the double-screw extruder is 48:1, and the temperature of each heating area is respectively set as follows: the temperature of the first zone is 150-200 ℃, the temperature of the second zone is 280-310 ℃, the temperature of the third zone is 285-310 ℃, the temperature of the fourth zone is 290-320 ℃, the temperature of the fifth zone is 290-320 ℃, the temperature of the sixth zone is 290-320 ℃, the temperature of the seventh zone is 290-320 ℃, the temperature of the eighth zone is 290-320 ℃, the temperature of the ninth zone is 290-320 ℃, the temperature of the tenth zone is 285-310 ℃, the temperature of the eleventh zone is 285-310 ℃, the temperature of the twelfth zone. The rotating speed of the screw is 300-360 r/min; the vacuum degree is-0.03 to-0.06 Mpa.

The PPS modified material with high precision, low overflow, low warpage and low dielectric constant and the preparation method thereof are described in more detail by the following specific examples, which are not intended to limit the present application.

Example 1

A high-precision low-overflow low-warpage low-dielectric PPS modified material comprises the following components in percentage by weight:

The high-precision low-overflow low-warpage low-dielectric PPS modified material is prepared from the raw materials in the proportion, and comprises the following steps:

(2) performing surface treatment on the mineral (I), and uniformly mixing the treated mineral (I), PPS, PPE, a compatilizer, a lubricant, an antioxidant, a halogen absorbent and a desulfurizing agent to obtain a mixture A;

(3) adding the mixture A into a main feeding port 1 (refer to figure 1) of a double-screw extruder 4, adding glass fiber into a first side feeding port 2 of the double-screw extruder 4, adding the mineral (II) into a second side feeding port 3 of the double-screw extruder 4, and performing melt extrusion and granulation. Wherein, the process conditions of the double-screw extruder are as follows: the length-diameter ratio of the double-screw extruder is 48:1, and the temperature of each heating area is respectively set as follows: 150 ℃ in the first zone, 280 ℃ in the second zone, 285 ℃ in the third zone, 290 ℃ in the fourth zone, 290 ℃ in the fifth zone, 310 ℃ in the sixth zone, 320 ℃ in the seventh zone, 320 ℃ in the eighth zone, 320 ℃ in the ninth zone, 310 ℃ in the tenth zone, 290 ℃ in the eleventh zone, 285 ℃ in the twelfth zone and 320 ℃ in the head. The rotating speed of the screw is 330 r/min; the vacuum degree is-0.03 MPa.

Wherein the step of surface treating the mineral (I) is as follows:

(1) preheating the mineral (I) in a stirrer at 80 ℃ for 10 min;

(2) adding a coupling agent KH560 into a stirrer to be mixed and stirred with the mineral (I), and controlling the temperature to be 70 ℃;

(3) and drying the stirred material for later use.

Examples 2 to 4

Examples 2-4 were prepared in substantially the same manner as in example 1, except that the raw materials were different in composition and content, and in examples 1-5, the specific components and contents are shown in Table 1.

TABLE 1 EXAMPLES 1-5 compositions of high-precision, Low-spill, Low-warp, Low-dielectric PPS modified materials

Comparative examples 1 to 3

Comparative examples 1 to 3 were prepared in substantially the same manner as in example 1 except that the raw materials were different in composition and content, and in comparative examples 1 to 3, reference was made to Table 2 for specific compositions and contents.

TABLE 2 composition of PPS-modified materials in comparative examples 1-3

The materials obtained in examples 1 to 5 and comparative examples 1 to 3 were subjected to the performance test, and the test results are shown in Table 3. Wherein the test items and conditions are as follows:

(1) tensile strength was tested according to ASTM D638. Specimen type is type I, specimen size (mm): (176. + -.2) (length) × (12.6. + -. 0.2) (end width) × (3.05. + -. 0.2) (thickness), and a drawing speed of 50 mm/min;

(2) flexural strength and flexural modulus were tested according to ASTM D790. Specimen type is specimen size (mm): (128. + -.2) × (12.67. + -. 0.2) × (3.11. + -. 0.2), bending speed 20 mm/min;

(3) notched Izod impact strength was tested according to ASTM D256. Sample type is type I, sample size (mm): (63 ± 2) × (12.45 ± 0.2) × (3.1 ± 0.2); the notch type is A type, and the residual thickness of the notch is 1.9 mm;

(4) heat distortion temperature: test according to ASTM D648, pressure: 1.82 Mpa;

(5) and (3) flame retardant test: test according to UL94 standard, thickness of the bar: 1.6 mm;

(6) melt flow rate: testing according to ASTM D1238, condition 310 ℃/5 kg;

(7) shrinkage rate: test according to ASTM D955, Machine Direction (MD), Transverse Direction (TD).

(8) Dielectric constant: according to the standard GB/T1409-2006, condition 1 GHZ.

(9) And (3) the other: and (4) whether the demoulding is warped or not and whether the product overflows from the mould or not are judged, and the result is obtained through visual inspection.

Table 3 results of property test of materials prepared in examples and comparative examples

As can be seen from Table 3, the PPS-modified materials of examples 1-5 of the present application had good mechanical strength (tensile strength, flexural strength and impact strength) and heat resistance, had low shrinkage and dielectric constant, and had no mold flash and warpage. Among them, in examples 1 to 4, as the content of the glass fiber and the cenosphere increases, the mechanical strength (tensile strength, bending strength, and impact strength) and the heat resistance of the material gradually increase, the fluidity, shrinkage rate, and dielectric constant of the material gradually decrease, and the overall performance of example 3 is the best.

Comparing example 3 with the data of example 5, it can be seen that the strength of the PPS modified material in example 5 is slightly lower than that in example 3, and the dielectric constant is higher than that in example 3, because the hollow glass beads are more easily broken than the hollow mullite beads when they are extruded by the screw to cause failure.

Comparative example 1 contains no PPE, and therefore, the material showed high fluidity, and mold flash occurred during molding of the product, resulting in flash.

Comparative example 2 does not contain whiskers, and therefore, the difference between the longitudinal shrinkage (MD) and the transverse shrinkage (TD) of the material is large, shrinkage is not uniform, and the product may warp after being demolded.

Comparative example 3 does not contain the mineral (II) cenospheres, so the dielectric constant of the material is relatively high, and the requirement on the low dielectric material (good wave permeability) in a 5G scene cannot be met.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims

1. The PPS modified material with high precision, low overflow, low warpage and low dielectric coefficient is characterized by comprising the following components in percentage by weight:

2. The PPS modified material as claimed in claim 1, wherein the glass fiber is cylindrical or flat.

3. The PPS modified material of claim 1, wherein the inorganic salt whisker material is selected from one or more of calcium salt, aluminum salt, magnesium salt and potassium salt.

4. The PPS modified material with high precision, low overflow and low warpage and low dielectric constant as claimed in claim 1, wherein the cenospheres are one or two of cenospheres and cenospheres.

5. The PPS modified material with high precision, low overflow and low warpage and low dielectric constant as claimed in claim 1, wherein the compatilizer is at least one of epoxy resin, SEBS-g-MAH, PPO-g-MAH and PS.

6. The PPS modified material with high precision, low overflow and low warpage and low dielectric constant as claimed in claim 1, wherein the lubricant is at least one selected from the group consisting of stearates, amides, silicones and waxes.

7. The high-precision low-spill low-warp low-dielectric PPS modified material as claimed in claim 1, wherein the halogen absorbent is at least one selected from calcium stearate, zinc stearate and magnesium stearate.

8. The PPS modified material as claimed in claim 1, wherein the sulfur removing agent is at least one selected from organic polyphosphonates, inorganic polyphosphates, hydroxycarboxylic acids and aminocarboxylic acids.

9. A preparation method of the high-precision low-overflow low-warpage low-dielectric PPS modified material as described in any one of claims 1-8, comprising the steps of:

(3) adding the mixture A into a main feeding port of a double-screw extruder, adding glass fiber into a first side feeding port of the double-screw extruder, adding the mineral (II) into a second side feeding port of the double-screw extruder, performing melt extrusion, granulating,

the process conditions are as follows: the length-diameter ratio of the double-screw extruder is 48:1, and the temperature of each heating area is respectively set as follows: 150-200 ℃ in the first area, 280-310 ℃ in the second area, 285-310 ℃ in the third area, 290-320 ℃ in the fourth area, 290-320 ℃ in the fifth area, 290-320 ℃ in the sixth area, 290-320 ℃ in the seventh area, 290-320 ℃ in the eighth area, 290-320 ℃ in the ninth area, 285-310 ℃ in the tenth area, 285-310 ℃ in the eleventh area, 285-310 ℃ in the twelfth area and 290-330 ℃ in the nose; the rotating speed of the screw is 300-360 r/min; the vacuum degree is-0.03 to-0.06 Mpa.

10. The method for preparing the PPS modified material with high precision, low overflow and low warpage and low dielectric constant as claimed in claim 9, wherein in the step (2), the mineral (I) is subjected to surface treatment and then to mixing operation, and the steps are as follows:

(1) preheating the mineral (I) in a stirrer at 60-100 deg.C for 10-20 min;

(3) and drying the stirred material for later use.