Patent Description:
Currently, radome substrates used on the market mainly include polytetrafluoroethylene (PTFE), polyimide (PI), etc. Such materials have high rigidity, high heat deformation temperature, and excellent electrical performance. However, material and processing costs of polytetrafluoroethylene and polyimide are high, and a processing temperature range of the polytetrafluoroethylene is narrow. In addition, the molecular structure of polyphenylene ether is rigid, and the products are prone to stress cracking, which is not suitable for secondary thermal processing.

<CIT> disclosed a low-filling high-heat conductivity insulating nylon/ polyphenylene ether composite material and a preparation method thereof. The composite material was prepared from a nylon resin, a polyphenylene ether resin, a flexibilizer, a modified magnesium oxide, an anti-oxidant, a lubricant and a titanium dioxide powder. The modified magnesium oxide was high-crystalline magnesium oxide having undergone surface treatment by an epoxy silane coupling agent KH560, and had good compatibility with the nylon matrix. The nylon resin and polyphenylene ether form a bicontinuous structure in situ and the modified magnesium oxide was selectively dispersed in a nylon phase, so heat-conductive net chains can be formed under the condition of a lower magnesium oxide filling amount, and a high heat conductivity coefficient and high mechanical properties were obtained; meanwhile, due to addition of polyphenylene ether, the electrical insulating property of the composite material was improved, and the composite material became an ideal material for a heat-radiation shell of an energy-saving LED lamp. <CIT> discloses a radome substrate made from a material comprising <NUM> to <NUM> weight% of a resin matrix, for example polyphenylene ether, <NUM> to <NUM> weight% hollow glass beads, <NUM> to <NUM> weight% of a lubricant and reinforcing glass fibers.

In the prior art, although polyphenylene ether substrates can also be used to manufacture radome substrates, there is no mention of stress cracking of polyphenylene ether resin and corresponding solutions. The radome substrate manufactured according to the prior art has obvious local cracks during the secondary thermal processing.

In order to overcome the disadvantage of the prior art, the present invention provides a radome substrate and a preparation method thereof.

According to one aspect of the present invention, a radome substrate includes, based on parts by weight:.

In the above radome substrate, the ceramic masterbatch is obtained by surface-modifying ceramic powder with a coupling agent, mixing the surface-modified ceramic powder with the second polyphenylene ether resin, and granulating them; and the ceramic powder comprises one or a combination of rutile TiO<NUM>, BaO<NUM>SrTi<NUM>, SrTiO<NUM>, BaTiO<NUM>, and CaCu<NUM>Ti<NUM>O<NUM>.

In the above radome substrate, the hollow microbead masterbatch is obtained by surface-modifying hollow glass microbeads with a coupling agent, mixing the surface-modified hollow glass microbeads with the third polyphenylene ether resin, and granulating them.

In the above radome substrate, the coupling agent comprises one or a combination of γ-aminopropyltriethoxysilane, γ-(<NUM>,<NUM>-epoxypropoxy), and propyl trimethoxy silane.

In the above radome substrate, the compatibilizer comprises one or a combination of polyphenylene oxide grafted maleic anhydride (PPO-g-MAH) and polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA), and a grafting rate of each of the polyphenylene-oxide-grafted-maleic-anhydride and the polyphenylene oxide grafted glycidyl methacrylate is <NUM>%-<NUM>%.

In the above radome substrate, the lubricant comprises one or a combination of glyceryl monostearate, N,N'-ethylene hisstearamide, ethylene bis-stearamide, ethylene stearamide, and polysiloxane.

According to another aspect of the present invention, a preparation method of the above radome substrate, comprises:.

In the above preparation method of the radome substrate, wherein in the step of preparing the ceramic masterbatch, using a coupling agent whose weight accounts for <NUM>% to <NUM>% of a total weight of the ceramic masterbatch to surface-modify the ceramic powder, wherein weights of the surface-modified ceramic powder and the second polyphenylene ether resin respectively account for <NUM>% to <NUM>% and <NUM>% to <NUM>% of the total weight of the ceramic masterbatch; and
in the step of preparing the hollow microbead masterbatch, using a coupling agent whose weight accounts for <NUM>% to <NUM>% of a total weight of the hollow microbead masterbatch to surface-modify the hollow glass microbeads, wherein weights of the surface-modified hollow glass microbeads and the third polyphenylene ether resin respectively account for <NUM>% to <NUM>% and <NUM>% to <NUM>% of the total weight of the hollow microbead masterbatch.

In the above preparation method of the radome substrate, the coupling agent comprises one or a combination of γ-aminopropyltriethoxysilane, γ-(<NUM>,<NUM>-epoxypropoxy), and propyl trimethoxy silane; the compatibilizer comprises one or a combination of polyphenylene oxide grafted maleic anhydride (PPO-g-MAH) and polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA); and the lubricant comprises one or a combination of glyceryl monostearate, N,N'-ethylene hisstearamide, ethylene bis-stearamide, ethylene stearamide, and polysiloxane.

In the above preparation method of the radome substrate, wherein before the step of surface-modifying the ceramic powder, the method further comprises: separately drying the ceramic powder and the second polyphenylene ether resin in an oven at <NUM> to <NUM> for <NUM> to <NUM> hours; and.

In order to improve the defect of poor stress resistance of the polyphenylene ether substrate, in the present invention, the ceramic powder is processed by using the coupling agent and then mixed with the second polyphenylene ether resin, so as to prepare the masterbatch. The hollow glass microbeads is processed by using the coupling agent and then mixed with the third polyphenylene ether resin, so as to prepare the masterbatch. And then the compatibilizer is added, so as to improve interface bonding strength between the first polyphenylene ether resin, the ceramic masterbatch, and the hollow microbead masterbatch, and improve distribution uniformity of the ceramic powder and the hollow glass microbeads in the first polyphenylene ether resin.

Particularly, the compatibilizer includes one or a combination of polyphenylene oxide grafted maleic anhydride (PPO-g-MAH) and polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA), which can effectively improve the interface bonding force between the first polyphenylene ether resin, the ceramic masterbatch, and the hollow microbead masterbatch. The ratio and content of ceramic powder and hollow glass microbeads are controlled to optimize a stacking and arrangement manner of the ceramic powder and the hollow glass microbeads, which can effectively improve the interface bonding force between the first polyphenylene ether resin, ceramic powder, and hollow glass microbeads. On the basis of maintaining the density and dielectric constant of the substrate, the defect of stress cracking resistance of the radome substrate manufactured by polyphenylene ether is effectively improved. The present invention provides a lightweight polyphenylene ether radome substrate having high dielectric constant and resistance to stress cracking, which effectively improves stress cracking resistance performance of the polyphenylene ether substrate.

To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments. <FIG> is a process flowchart of preparing a radome substrate according to an embodiment of the present invention.

The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention shall fall within the protection scope of the present invention.

The present invention provides a radome substrate and a preparation method thereof, wherein the preparation method of the radome substrate includes the following steps.

As shown in step S101 in <FIG>, surface-modifying ceramic powder, uniformly mixing the surface-modified ceramic powder with a second polyphenylene ether resin, and granulating them to prepare ceramic masterbatch. Specifically, firstly drying the ceramic powder and the second polyphenylene ether resin in an oven at <NUM> to <NUM> for <NUM> to <NUM> hours; and surface-modifying the ceramic powder, uniformly mixing the surface-modified ceramic powder with the second polyphenylene ether resin, and granulating them to prepare ceramic masterbatch. In this step, the ceramic powder is surface-modified by using the coupling agent that accounts for <NUM>% to <NUM>% of the total weight of the ceramic masterbatch, and weights of the surface-modified ceramic powder and the second polyphenylene ether resin account for <NUM>% to <NUM>% and <NUM>% to <NUM>% of the total weight of the ceramic masterbatch respectively. The coupling agent includes one or a combination of γ-aminopropyltriethoxysilane, γ-(<NUM>,<NUM>-epoxypropoxy), and propyl trimethoxy silane.

As shown in step S103 in <FIG>, surface-modifying hollow glass microbeads, uniformly mixing the surface-modified hollow glass microbeads with a third polyphenylene ether resin, and granulating them to prepare hollow microbead masterbatch. Specifically, firstly drying the hollow glass microbeads and the third polyphenylene ether resin in an oven at <NUM> to <NUM> for <NUM> to <NUM> hours; and then surface modifying the hollow glass microbeads, uniformly mixing the surface-modified hollow glass microbeads with the third polyphenylene ether resin, and granulating them to prepare the hollow microbead masterbatch. In this step, the hollow glass microbeads are surface-modified by using the coupling agent that accounts for <NUM>% to <NUM>% of a total weight of the hollow microbead masterbatch, and weights of the surface-modified hollow glass microbeads and the third polyphenylene ether resin account for <NUM>% to <NUM>% and <NUM>% to <NUM>% of the total weight of the hollow microbead masterbatch respectively. The coupling agent includes one or a combination of γ-aminopropyltriethoxysilane, γ-(<NUM>,<NUM>-epoxypropoxy), and propyl trimethoxy silane.

As shown in step S105 in <FIG>, based on parts by weight, taking <NUM> to <NUM> parts of the first polyphenylene ether resin, <NUM> to <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> to <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> to <NUM> parts of compatibilizer, and <NUM> to <NUM> parts of lubricant, adding them to a high-speed mixer, uniformly mixing them, and hot pressing them to prepare the radome substrate. The compatibilizer includes one or a combination of polyphenylene oxide grafted maleic anhydride (PPO-g-MAH) and polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA), and a grafting rate of each of the polyphenylene-oxide-grafted-maleic-anhydride and the polyphenylene oxide grafted glycidyl methacrylate is <NUM>%-<NUM>%. The lubricant includes one or a combination of glyceryl monostearate, N,N'-ethylene hisstearamide, ethylene bis-stearamide, ethylene stearamide, and polysiloxane. In this step, the hot pressing is performed by a hot press machine, the operating temperature of the hot press machine is <NUM> to <NUM>, and the operating pressure of the hot press machine is <NUM> to 50MPa.

The following clearly and completely describes the technical solutions in the present invention with reference to specific embodiments.

Separately drying ceramic powder and second polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the ceramic powder with the coupling agent (for example γ-aminopropyltriethoxysilane), uniformly mixing the surface-modified ceramic powder with the second polyphenylene ether resin, and granulating them by using a granulator to prepare ceramic masterbatch.

Wherein, the ceramic powder is surface-modified by using the coupling agent that accounts for <NUM>% of the total weight of the ceramic masterbatch, and weights of the surface-modified ceramic powder and the second polyphenylene ether resin account for <NUM>% and <NUM>% of the total weight of the ceramic masterbatch respectively.

Separately drying hollow glass microbeads and third polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the hollow glass microbeads with the coupling agent (for example γ-aminopropyltriethoxysilane), uniformly mixing the surface-modified hollow glass microbeads with the third polyphenylene ether resin, and granulating them by using a granulator to prepare hollow microbead masterbatch.

Wherein, the hollow glass microbeads are surface-modified by using the coupling agent that accounts for <NUM>% of a total weight of the hollow microbead masterbatch, and weights of the surface-modified hollow glass microbeads and the third polyphenylene ether resin account for <NUM>% and <NUM>% of the total weight of the hollow microbead masterbatch respectively.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example N,N'-ethylene hisstearamide), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate. Wherein, the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 20MPa.

Separately drying ceramic powder and second polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the ceramic powder with the coupling agent (for example γ-(<NUM>,<NUM>-epoxypropoxy)), uniformly mixing the surface-modified ceramic powder with the second polyphenylene ether resin, and granulating them by using a granulator to prepare ceramic masterbatch.

Separately drying hollow glass microbeads and third polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the hollow glass microbeads with the coupling agent (for example γ-(<NUM>,<NUM>-epoxypropoxy)), uniformly mixing the surface-modified hollow glass microbeads with the third polyphenylene ether resin, and granulating them by using a granulator to prepare hollow microbead masterbatch.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of the ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of the hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example glyceryl monostearate), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate. Wherein, the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 30MPa.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example polysiloxane), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate. Wherein, the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 50MPa.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example ethylene stearamide), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate. Wherein, the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 40MPa.

Separately drying ceramic powder and second polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the ceramic powder with the coupling agent (for example propyl trimethoxy silane), uniformly mixing the surface-modified ceramic powder with the second polyphenylene ether resin, and granulating them by using a granulator to prepare ceramic masterbatch.

Separately drying hollow glass microbeads and third polyphenylene ether resin in an oven at <NUM> for <NUM> hours, surface-modifying the hollow glass microbeads with the coupling agent (for example propyl trimethoxy silane), uniformly mixing the surface-modified hollow glass microbeads with the third polyphenylene ether resin, and granulating them by using a granulator to prepare hollow microbead masterbatch.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example ethylene bis-stearamide), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate. Wherein the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 35MPa.

Wherein, the hollow glass microbeads are surface-modified by using the coupling agent that accounts for <NUM>% of a total weight of the hollow microbead masterbatch, and weights of the surface-modified hollow glass microbeads and the second polyphenylene ether resin account for <NUM>% and <NUM>% of the total weight of the hollow microbead masterbatch respectively.

Based on parts by weight, taking <NUM> parts of first polyphenylene ether resin, <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> parts of compatibilizer (for example polyphenylene oxide grafted glycidyl methacrylate (PPO-g-GMA)), and <NUM> parts of lubricant (for example N,N'-ethylene hisstearamide), adding them to a high-speed mixer, uniformly mixing them, and hot pressing them by using a hot press machine to prepare the radome substrate, wherein the operating temperature of the hot press machine is <NUM>, and the operating pressure of the hot press machine is 45MPa.

It is visually observed whether the radome substrate cracks, and the result shows that the radome substrate prepared in Embodiment <NUM> to Embodiment <NUM> does not crack.

On the basis of maintaining substrate density and a dielectric constant, the radome substrate manufactured according to the method provided in the embodiments of the present invention effectively alleviates an stress cracking resistance disadvantage of the radome substrate.

In the present invention, the ceramic powder processed by using the coupling agent and the hollow glass microbeads processed by using the coupling agent each are made into the masterbatches respectively by using the second polyphenylene ether resin and the third polyphenylene ether resin, and then the compatibilizer is added, to improve interface bonding strength between the first polyphenylene ether resin, the ceramic masterbatch, and the hollow microbead masterbatch, and improve distribution uniformity of the ceramic powder and the hollow glass microbeads in the first polyphenylene ether resin. Proportions and content of the ceramic powder and the hollow glass microbeads are controlled to optimize a stacking and arrangement manner of the ceramic powder and the hollow glass microbeads, to effectively reduce stress concentration between the first polyphenylene ether resin, the ceramic powder, and the hollow glass microbeads. On the basis of maintaining substrate density and a dielectric constant, an stress cracking resistance disadvantage of a radome substrate manufactured by using polyphenylene ether is effectively alleviated.

Claim 1:
A radome substrate, characterized in that, comprising, based on parts by weight:
polyphenylene ether resin consisting of a first polyphenylene ether resin, a second polyphenylene ether resin, and a third polyphenylene ether resin;
<NUM> to <NUM> parts of the first polyphenylene ether resin , <NUM> to <NUM> parts of ceramic masterbatch comprising the second polyphenylene ether resin, <NUM> to <NUM> parts of hollow microbead masterbatch comprising the third polyphenylene ether resin, <NUM> to <NUM> parts of a compatibilizer, and <NUM> to <NUM> parts of a lubricant.