Millimeter-Wave Radar Housing Material Capable of Being Laser Welded, and Preparation Method Therefor

Abstract

A millimeter-wave radar housing material capable of being laser welded, and a preparation method therefor, which belong to the technical field of millimeter-wave radar housing manufacturing. The millimeter-wave radar housing material specifically comprises the following components in parts by weight: 50-90 parts of polypropylene, 10-50 parts of glass fiber, 0.2-0.8 part of a nucleating agent, 0.5-1 part of a compatibilizer, 0.1-0.5 part of a black colorant, 0.1-0.5 part of an antioxidant, and 0.1-0.8 part of a light stabilizer. The radar housing material disclosed by the present invention has the advantages of low dielectricity, being lightweight, high strength and high heat resistance, can transmit a near-infrared light beam, and has laser weldability.

Claims

1. A millimeter-wave radar housing material capable of being laser welded, comprising the following components in parts by weight: TABLE-US-00005 polypropylene 50-90 glass fiber 10-50 nucleating agent 0.2-0.8 compatibilizer 0.5-1   organic black colorant 0.1-0.5 antioxidant 0.1-0.5 light stabilizer  0.1-0.8.

2. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the polypropylene is one or more of a high flow homo-polypropylene or a co-polypropylene.

3. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the glass fiber is one or more of an alkali-free glass fiber yarn treated with a silane-type impregnating agent.

4. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the nucleating agent is a nano-scale acicular attapulgite having an aspect ratio of 30-50 and an average particle size of 5-8 micrometers.

5. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the compatibilizer is a graft polymer of maleic anhydride and polyolefin, and the maleic anhydride graft ratio is 1.0%-2.5%.

6. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the organic black colorant is compounded by solvent red, solvent blue, solvent green, and solvent yellow in a weight ratio of (6-8):(3-5):(1-3):(0.5-1).

7. The millimeter-wave radar housing material capable of being laser welded of claim 6, characterized in that, the solvent red is E2G; the solvent blue is RR; the solvent green is 5B; the solvent yellow is Yellow G.

8. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the antioxidant is one or more of antioxidants such as hindered phenols, phosphite esters and thioester etc.

9. The millimeter-wave radar housing material capable of being laser welded of claim 1, characterized in that, the light stabilizer is one or more of light stabilizer such as hindered amines, benzotriazoles, and benzophenones etc.

10. The preparation method for a millimeter-wave radar housing material capable of being laser welded of claim 1, comprising the steps of: adding polypropylene, a compatibilizer, an antioxidant, a black colorant, a nucleating agent and a light stabilizer into a mixer in parts by weight, thoroughly and homogeneously mixing the same to obtain a premix; adding the premix into a twin-screw extruder; extruding the resulting resin melt into an impregnation die connected to a head of the twin-screw extruder; then passing the continuous glass fiber through the impregnation die, sufficiently impregnating the continuous glass fiber with the melt; finally cooling, drawing and pelletizing the resultant material to obtain a millimeter-wave radar housing material capable of being laser welded.

Description

DESCRIPTION OF THE EXAMPLES

[0028] The present invention will be described in further detail with reference to examples.

EXAMPLES

[0029] A millimeter-wave radar housing material capable of being laser welded comprising the following components in parts by weight:

TABLE-US-00002 polypropylene 50-90 glass fiber 10-50 nucleating agent 0.2-0.8 compatibilizer 0.5-1   organic black colorant 0.1-0.5 antioxidant 0.1-0.5 light stabilizer 0.1-0.8

[0030] The polypropylene is one or more of high flow homo-polypropylene or co-polypropylene.

[0031] The glass fiber is one or more of an alkali-free glass fiber yarn treated with a silane-type impregnating agent.

[0032] The nucleating agent is a nano-size acicular attapulgite having an aspect ratio of 30-50 and a particle size distribution of 5-8 microns.

[0033] The compatibilizer is a graft polymer of maleic anhydride and polyolefin, and the graft ratio of maleic anhydride is 1.0%-2.5%.

[0034] The black colorant is compounded by solvent red, E2G, solvent blue, RR, solvent green, 5B, and solvent yellow, Yellow G in a weight ratio of 8:5:3:1. Solvent Yellow, Yellow G is selected from LANXESS solvent colorant MACROLEX® Yellow G.

[0035] The antioxidant is one or more of antioxidants such as hindered phenols, amines, phosphite esters, and thioester etc. Preferably, the antioxidant is compounded by 1010 and 168 in a weight ratio of 1:1 or 1:2.

[0036] The light stabilizer is one or more of light stabilizers such as hindered amines, benzotriazoles, and benzophenones etc.

[0037] The formulations of Examples 1-4 are shown in Table 1. The preparation of the examples comprises the following steps:

[0038] adding polypropylene, a compatibilizer, an antioxidant, a black colorant, a nucleating agent and a light stabilizer into a mixer in a certain proportion, thoroughly and homogeneously mixing the same; adding the premix into a twin-screw extruder;

[0039] extruding the resulting resin melt into an impregnation die connected to a head of the twin-screw extruder; then passing the continuous glass fiber through the impregnation die, sufficiently impregnating the continuous glass fiber with the melt; finally cooling, drawing and pelletizing the resultant material to obtain a millimeter-wave radar housing pellet material capable of being laser welded.

[0040] The pellet material was dried at 90° C. for 3 hours and subjected to injection molding, wherein the operating conditions of the injection molding machine can be as follows: the temperature of the first zone was 200-220° C.; the temperature of the second zone was 230-240° C.; the temperature of the third zone was 240-250° C.; the temperature of the fourth zone was 245-255° C.; the pressure was 60-90 MPa; the speed was 30-50 mm/s. Among them, a set of standard sample bars were tested for mechanical properties, and 60 * 20 * 2 bars were laser welded in an overlapping manner.

[0041] Test criteria and conditions for the examples: tensile strength was measured according to ISO 527 with a tensile speed of 50 mm/min; the flexural strength was tested according to ISO 178 at a test speed of 2 mm/min; the notched izod impact strength was tested according to ISO 180, V-shaped notch; un-notched Charpy impact strength was tested according to IS0179; the heat distortion temperature was tested according to IS075-2, load: 1.8MPa; the dielectric property was tested according to SJ 20512-1995, frequency: 77 GHz; laser transmittance: ultraviolet-visible near-infrared spectrophotometer Lambda 950, 60mm*60mm*2mm smooth surface plate, wavelength: 800-1200 nm.

TABLE-US-00003 TABLE 1 Formulations of Examples 1-4 and Comparative examples Compar- ative Example Example Example Example example Formulation 1 2 3 4 1 Homo-PP 60 50 60 70 Co-PP 20 20 70 Continuous 20 30 40 30 glass fiber Short glass 30 fiber Attapulgite 0.7 0.5 0.2 0.6 0 PP-g-MAH 0.5 0.5 0.8 1 1 Black 0.2 0.5 0.4 0.3 colorant Carbon black 0.5 colorant Antioxidant 0.1 0.1 0.2 0.2 0.2 1010 Antioxidant 0.1 0.2 0.2 0.3 0.2 168 Stabilizer 0.3 0.2 0.2 0.3 770 Stabilizer 0.2 0.4 0.2 944 UV-531 0.5

TABLE-US-00004 TABLE 2 Performance Test Results for Examples 1-4 and Comparative examples Compar- ative Example Example Example Example example Examples 1 2 3 4 1 Density 1.05 1.12 1.22 1.12 1.12 Tensile Strength/MPa 72 98 124 110 70 Elongation at break 2.3 1.9 2.6 2 3.5 Flexural Modulus/MPa 4200 6000 8300 6700 4000 Flexural Strength/MPa 120 155 185 160 90 Notched izod impact 20 25 28 23 10 strength/kJ .Math. m-2 Un-notched Charpy 55 63 66 61 45 impact strength/kJ .Math. m-2 Heat distortion 136 155 162 160 115 temperature HDT (1.8 MPa) Dielectric constant Dk 2.46 2.6 2.71 2.59 2.62 Transmittance (950 nm) 53% 43% 35% 46% 0

[0042] By way of illustration of the examples, the present invention selects general-purpose plastic polypropylene as the substrate, and adds the alkali-free glass fiber yarn, so as to impart the advantages of high strength and high heat resistance to the material by production through the LFT-G process and the induced crystallization of the nucleating agent. The size of PP spherulite can be refined by attapulgite, which is beneficial to the penetrability of millimeter-wave and reduces the dielectric constant of the material, so as to meet the requirements of high strength, high heat resistance and high wave penetration of 5G radar housing. In addition, the refined spherulite size of PP can reduce the scattering effect of the material on the laser beam, and improve the transmittance of the material, without affecting the transmittance of the material under the action of the organic dye. The millimeter-wave radar housing can be connected to the mounting surface by laser welding. The welding strength is high, and it is not easy to be damaged, which solves a series of problems caused by easy loosening and poor sealing of the existing connection methods.

[0043] The present invention includes, but is not limited to, the above examples, and it is intended that improvements and modifications made without departing from the scope of the present invention should all fall within the scope of the present invention. In addition, the material of the present invention can be used not only in millimeter wave radar housings, but also in fields of various radomes requiring low dielectric constant.