PP / PET alloy material and preparation method and application thereof

Abstract

The invention relates to a PP / PET alloy material and a preparation method and application thereof. The PP / PET alloy material is prepared from the following components in parts by weight: 20 to 50 parts of PP resin, 19 to 51 parts of PET resin, 20 to 35 parts of flat glass fiber and 3 to 5 parts of compatilizer. According to the invention, the PET resin with specific intrinsic viscosity, the flat glass fiber and the compatilizer are added, so that the obtained PP / PET alloy material has high surface energy and good microdefect self-repairing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, and more particularly to a PP / PET alloy material and a preparation method and application thereof. BACKGROUND

[0002] Polypropylene (PP) has the advantages of low density, easy processing, good impact performance, mature production, and large supply. Polyethylene terephthalate (PET) has high tensile strength, rigidity, and hardness, and good wear resistance and creep resistance. The PP / PET alloy combines the advantages of PP and PET, and is mainly applied to automotive interior and exterior parts. The interior parts include instrument panels, door panels, and pillars, and the exterior parts include bumpers, fenders, and air deflectors. In particular, as a glass fiber reinforced PP / PET alloy with excellent mechanical properties and rigidity strength, it has replaced painted products in a large area and is used in various automotive exterior parts, improving the protection of the exterior parts on the vehicle body, and increasing the aesthetic and economic properties.

[0003] In recent years, outdoor off-road and crossing have gradually emerged, and these scenarios have put forward some requirements for glass fiber reinforced PP / PET alloy exterior parts. 1) Outdoor off-road vehicles may be refinished, but the current glass fiber reinforced PP / PET alloy has low surface energy, which makes it difficult for paint or paint to adhere well to the refinished position of the exterior part.

[0004] 2) Field crossing can cause some micro defects in the part, which can be clearly seen under sunlight, i.e., "sun lines", which affect the appearance of the exterior part. If the part is replaced frequently due to micro defects, it will obviously bring great cost to the user.

[0005] The prior art pays little attention to the above problems. SUMMARY

[0006] The primary object of the present application is to overcome the problems existing in the prior art and provide a PP / PET alloy material.

[0007] A further object of the present application is to provide a preparation method of the above-mentioned PP / PET alloy material.

[0008] A further object of the present application is to provide the application of the above-mentioned PP / PET alloy material in the preparation of automotive parts.

[0009] The above objects of the present application are achieved by the following technical solutions: A PP / PET alloy material, comprising the following components by weight: PP resin 20-50 parts, PET resin 19-51 parts, Flat glass fiber 20-35 parts, compatibility agent 3~5 parts; The intrinsic viscosity of the PET resin is 0.8~1.15dL / g.

[0010] The inventor of the present application found that the PP / PET alloy material can realize micro defect self-repairing by using flat glass fiber to reinforce the PP / PET alloy material, and adding compatibility agent and regulating the intrinsic viscosity of the PET resin.

[0011] The principle is as follows: the addition of the compatibility agent is beneficial to the compatible dispersion of the PP resin and the PET resin, and further makes the PET resin on the surface of the PP / PET alloy material well dispersed. When the micro defect is formed on the surface of the PP / PET alloy material, the PET resin can “pull back” the scraped resin by using its own high viscosity, so that the surface of the material is as flat as possible, and the micro defect self-repairing is realized.

[0012] If the ordinary glass fiber (cross section is circular) is used, or if the intrinsic viscosity of the PET resin is too high, it is not conducive to the good dispersion of the PET resin on the surface of the PP / PET alloy material, and the micro defect self-repairing performance of the PP / PET alloy material is poor. If the intrinsic viscosity of the PET resin is too low, it is difficult to “pull back” the scraped resin, and the micro defect self-repairing performance of the PP / PET alloy material is poor.

[0013] In addition, the regulation of the amount of the PET resin also makes the PP / PET alloy material of the present application have high surface energy.

[0014] In the present application, the amount of the PP resin can be specifically 20, 25, 30, 35, 40, 45, 50 parts by weight or a range value formed by any two of the above values; the amount of the PET resin can be specifically 19, 20, 25, 30, 35, 40, 45, 50, 51 parts by weight or a range value formed by any two of the above values; the amount of the flat glass fiber can be specifically 20, 25, 30, 35 parts by weight or a range value formed by any two of the above values; and the amount of the compatibility agent can be specifically 3, 3.5, 4, 4.5, 5 parts by weight or a range value formed by any two of the above values.

[0015] Preferably, the PP / PET alloy material comprises the following components in parts by weight: PP resin 20~30 parts, PET resin 40~50 parts, Flat glass fiber 30~35 parts, Compatibility agent 4~5 parts.

[0016] The amount of each component is regulated within the range, and the micro defect self-repairing ability of the obtained PP / PET alloy material is better.

[0017] In the present application, the sum of the mass of the PP resin and the PET resin accounts for more than 50wt% of the PP / PET alloy material.

[0018] Preferably, the melt flow rate of the PP resin is 2-50g / 10min measured at 230℃ under the condition of 2.16kg.

[0019] In the present application, the melt flow rate of the PP resin can be measured according to ISO 1133:2022.

[0020] Preferably, the PP resin is at least one of homopolypropylene or copolypropylene.

[0021] More preferably, the copolypropylene is at least one of block copolypropylene or random copolypropylene.

[0022] Preferably, the mass ratio of the PP resin and the PET resin is (5-7):(7-9).

[0023] More preferably, the mass ratio of the PP resin and the PET resin is (5-6):(8-9).

[0024] By controlling the mass ratio of the PP resin and the PET resin within the range, the PP / PET alloy material obtained has better micro flaw self-repairing ability.

[0025] In the present application, the PET resin can be purchased or self-made.

[0026] The self-made process can be as follows: terephthalic acid and ethylene glycol first undergo esterification, then undergo polycondensation and solid phase tackifying, and the PET resin is obtained.

[0027] Preferably, the molar ratio of the terephthalic acid and the ethylene glycol is 1:1.2-1.6.

[0028] Preferably, the esterification is carried out in the presence of a catalyst; the catalyst includes but is not limited to antimony catalyst (such as diantimony trioxide); the catalyst is 0.03-0.06% of the mass of the terephthalic acid.

[0029] Preferably, the esterification is carried out at a temperature of 250-260℃, a pressure of 0.2-0.4MPa, and a time of 1-4 hours.

[0030] Preferably, the polycondensation is carried out at a pressure of ≤100Pa, a temperature of 270-285℃, and a time of 1-2 hours.

[0031] Preferably, after the polycondensation, the process further includes the steps of extrusion and slicing before the solid phase tackifying.

[0032] Preferably, the solid-phase thickening temperature is 210~230℃ and the time is 10~16 hours.

[0033] Preferably, the solid-phase thickening is carried out in a nitrogen atmosphere.

[0034] In this invention, the intrinsic viscosity of the PET resin can be measured by an Ubbelohde viscometer at 25°C. The solvent is a mixed solvent of phenol and tetrachloroethane with a volume ratio of 3:2, and the solution concentration is 0.005 g / mL.

[0035] The intrinsic viscosity of PET resin can be 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.10 or 1.15 dL / g.

[0036] Preferably, the intrinsic viscosity of the PET resin is 0.9~1.0 dL / g.

[0037] By adjusting the intrinsic viscosity of PET resin within this range, the resulting PP / PET alloy material exhibits better self-healing capabilities for minor defects.

[0038] Preferably, the average length of the flat glass fiber is 2-5 mm and the flatness ratio is 3-6.

[0039] More preferably, the flat glass fiber has an aspect ratio of 4 to 6.

[0040] By adjusting the flatness ratio of the flat glass fibers within this range, the resulting PP / PET alloy material exhibits better self-healing capabilities for minor defects.

[0041] Preferably, the average cross-sectional long diameter of the flat glass fiber is 8~15μm.

[0042] The average length, average long diameter, and average short diameter of the flat glass fiber can be measured by optical microscopy, and the flatness ratio can be obtained by calculation.

[0043] Preferably, the compatibilizer is at least one of maleic anhydride type compatibilizer, epoxy type compatibilizer, or thermoplastic polyester elastomer.

[0044] More preferably, the compatibilizer is a thermoplastic polyester elastomer.

[0045] Using thermoplastic polyester elastomers results in PP / PET alloy materials with better self-healing capabilities for minor defects.

[0046] More preferably, the thermoplastic polyester elastomer is at least one of a polyether-type polyester elastomer or a polyester-type polyester elastomer.

[0047] More preferably, the soft segment of the polyether-type polyester elastomer is at least one of polytetrahydrofuran (PTMG), polyethylene glycol (PEG), or polybutanediol (PBG); the hard segment of the polyether-type polyester elastomer is an aromatic polyester, including but not limited to at least one of polybutylene terephthalate, polyethylene terephthalate, and polypropylene terephthalate.

[0048] More preferably, the soft segment of the polyester elastomer is at least one of polyglycolic acid, polylactide, or polycaprolactone; the hard segment of the polyether elastomer is an aromatic polyester, including but not limited to at least one of polybutylene terephthalate, polyethylene terephthalate, and polypropylene terephthalate.

[0049] More preferably, the maleic anhydride compatibilizer includes, but is not limited to, at least one of maleic anhydride-grafted polypropylene or maleic anhydride-grafted POE.

[0050] More preferably, the epoxy compatibilizer includes, but is not limited to, at least one of glycidyl methacrylate copolymer-grafted styrene-acrylonitrile copolymer, glycidyl methacrylate-grafted polypropylene, or glycidyl methacrylate-POE.

[0051] Preferably, the PP / PET alloy material further includes 0.5 to 1.5 parts of other additives.

[0052] More preferably, the other additives include, but are not limited to, at least one of antioxidants, light stabilizers, or lubricants.

[0053] Optionally, the antioxidant includes, but is not limited to, at least one of hindered phenolic antioxidants or phosphite antioxidants.

[0054] Optionally, the light stabilizer includes, but is not limited to, at least one of hindered amine light stabilizers.

[0055] Optionally, the lubricant includes, but is not limited to, at least one of stearic acid metal salt compounds.

[0056] The preparation method of the above-mentioned PP / PET alloy material includes the following steps: mixing the components, melt extruding, and granulating to obtain the PP / PET alloy material.

[0057] Preferably, the temperature of the melt extrusion is 130~265℃; the screw speed of the extruder for the melt extrusion is 400~600 rpm.

[0058] The application of the aforementioned PP / PET alloy material in the manufacture of automotive parts is also within the scope of protection of this invention.

[0059] An automotive component is made from the aforementioned PP / PET alloy material.

[0060] Preferably, the automotive component is an exterior trim piece for an off-road vehicle.

[0061] Compared with the prior art, the beneficial effects of the present invention are: The present invention incorporates PET resin with specific intrinsic viscosity, flat glass fiber, and compatibilizer to obtain PP / PET alloy material with high surface energy and good self-healing properties for minor defects. Detailed Implementation

[0062] To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention.

[0063] The reagents used in the various embodiments and comparative examples of this invention are described below: PP resin #1: PPH-Z30S, Sinopec Beihai, melt index is 30g / 10min (230℃, 2.16kg). PP resin #2: PP HP500N-Z, CNOOC Shell, melt index is 10g / 10min (230℃, 2.16kg). PP resin #3: PPH-T03, Sinopec Maoming, melt index is 3g / 10min (230℃, 2.16kg). PET Resin 1#: Self-made, the process is as follows: Terephthalic acid and ethylene glycol are mixed in a molar ratio of 1.0:1.5, and then antimony trioxide catalyst (0.05wt% of terephthalic acid) is added and mixed well. Then, the mixture is reacted at 258℃ and 0.2MPa for 3 hours; then, it is reacted at 275℃ under vacuum conditions of <100Pa for 1.5 hours. The mixture is then extruded, cooled, and sliced ​​to obtain PET resin chips. The PET resin chips are kept at 220℃ in a nitrogen atmosphere for 12 hours to achieve solid-phase thickening, thus obtaining PET Resin 1#; the intrinsic viscosity of PET Resin 1# is 0.9dL / g. PET Resin 2#: Self-made, the process differs from PET Resin 1# in that: the solid phase thickening time is 14 hours; the intrinsic viscosity of PET Resin 2# is 1.0 dL / g; PET resin #3: Homemade, the process differs from PET resin #1 in that: the solid phase thickening time is 10 hours; the intrinsic viscosity of PET resin #3 is 0.8 dL / g. PET resin #4: Homemade, the process differs from PET resin #1 in that: the solid phase thickening time is 16 hours; the intrinsic viscosity of PET resin #4 is 1.1 dL / g. PET resin #5: Homemade, the process differs from PET resin #1 in that: the solid phase thickening time is 9 hours; the intrinsic viscosity of PET resin #5 is 0.7 dL / g. PET resin 6#: self-made, the process differs from PET resin 1# in that: the solid phase thickening time is 17 hours; the intrinsic viscosity of PET resin 6# is 1.3 dL / g; The intrinsic viscosity of the above-mentioned PET resin was measured by Ubbelohde viscometer at 25°C. The solvent was a mixture of phenol and tetrachloroethane with a volume ratio of 3:2, and the solution concentration was 0.005 g / mL. Fiberglass 1#: aspect ratio 3, average length 3mm, cross-sectional long diameter 10μm, ECS3F-03-568H, Jushi Group; Glass fiber 2#: aspect ratio of 4, average length of 3mm, cross-sectional long diameter of 10μm, ECS301-HP-3-M4, Chongqing Glass Fiber; Fiberglass 3#: aspect ratio 6, average length 3mm, cross-sectional long diameter 10μm, ECS4F-03-534A, Jushi Group; Fiberglass 4#: ECS13-03-508A, average diameter 13um, average length 3mm, manufacturer: Jushi Group; Compatibilizer 1#: Rizhisheng, SAG-002, styrene-acrylonitrile copolymer grafted with glycidyl methacrylate; Compatibilizer 2#: Hechuang, H40DMG, thermoplastic polyester elastomer; Compatibilizer 3#: BONDYRAM, PA BOND 363C, maleic anhydride grafted polypropylene; Other additives #1: Antioxidant 1010, commercially available; Unless otherwise specified, all components (e.g., other additives 1#) used in the parallel examples and comparative examples are the same commercially available products.

[0064] The PP / PET alloy materials provided in the embodiments and comparative examples of this invention were subjected to performance testing according to the following test methods: 1. Dyne Value: Using a standard dyne pen, apply the ink to the sample surface and observe the spreading and shrinkage time of different dyne pens to determine the corresponding dyne value: If the ink shrinks and gathers rapidly after application, it is determined that the dyne value corresponding to that dyne pen has not been reached; if the ink does not gather much after application or remains spread out, it is determined that the dyne value corresponding to that dyne pen has been reached. The higher the dyne value, the higher the surface energy.

[0065] 2. Micro-imperfection self-healing: PP / PET alloy material is injection molded into a 100*100*3.0mm square plate. Then, micro-imperfections are scratched using a fixed normal force of 1N and an experimental speed of 1000mm / min. The average depth L0 of 5 micro-imperfections is measured and recorded using an optical microscope. After being placed at room temperature for 48 hours, the average depth L1 of 5 micro-imperfections is measured and recorded again using an optical microscope. The recovery status of the micro-imperfections is calculated as δL=L0-L1; the larger δL is, the better the self-healing ability of the micro-imperfections.

[0066] The PP / PET alloy materials of the embodiments and comparative examples of the present invention were prepared by the following method: According to the formula, each component is put into a high-speed mixer and mixed for 5 minutes at a speed of 500 r / min to obtain a mixture. The mixture is then extruded and granulated through a twin-screw extruder to obtain PP / PET alloy material. The temperatures of each zone of the screw are set sequentially to 180℃, 220℃, 220℃, 240℃, 260℃, 260℃, 260℃, 265℃, and 265℃, with a speed of 500 rpm and a screw length-to-diameter ratio of 75:1 to obtain the PP / PET alloy material.

[0067] Examples 1-14 Examples 1-14 provide a series of PP / PET alloy materials, the formulations of which are shown in Table 1.

[0068] Table 1. Formulations (parts by weight) for Examples 1-14 .

[0070] Comparative Examples 1-5 Comparative Examples 1-5 provide a series of PP / PET alloy materials, the formulations of which are shown in Table 2.

[0071] Table 2 Formulations (parts by weight) for Comparative Examples 1-5

[0072] The properties of the PP / PET alloy materials in each embodiment and comparative example were determined according to the test methods mentioned above, and the test results are shown in Table 3.

[0073] Table 3. Performance test results of PP / PET alloy materials in each embodiment and comparative example. .

[0075] The initial average depth L0 of the defects in each embodiment and comparative example is between 80 and 100 μm.

[0076] As can be seen from Table 3: The dyne values ​​of the PP / PET alloy materials in Examples 1-14 are all 34 or above, and the degree of micro-impact self-healing reaches 43 μm or above, indicating that the PP / PET alloy materials of the present invention have high surface energy and good micro-impact self-healing performance.

[0077] In Comparative Examples 1 and 2, the viscosity of the added PET resin was either too low or too high, resulting in poor self-healing properties of the PP / PET alloy material. In Comparative Example 3, the amount of added PET resin was too small, leading to low surface energy of the PP / PET alloy material and poor self-healing properties. In Comparative Example 4, ordinary glass fiber was added instead of flat glass fiber, resulting in poor self-healing properties of the PP / PET alloy material. In Comparative Example 5, no compatibilizer was added, resulting in poor self-healing properties of the PP / PET alloy material.

[0078] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A PP / PET alloy material, characterized in that, The PP / PET alloy material comprises the following components in parts by weight: PP resin 20-50 parts, PET resin 19-51 parts, Flat glass fiber 20-35 parts, Compatibility agent 3-5 parts; The intrinsic viscosity of the PET resin is 0.8-1.15 dL / g.

2. The PP / PET alloy material according to claim 1, characterized in that, The melt flow rate of the PP resin is 2-50 g / 10 min measured at 230°C under a load of 2.16 kg. and / or, The intrinsic viscosity of the PET resin is 0.9-1.0 dL / g.

3. The PP / PET alloy material according to claim 1, characterized in that, The mass ratio of the PP resin to the PET resin is (5-7):(7-9).

4. The PP / PET alloy material according to claim 1, characterized in that, The flat glass fiber has an average length of 2-5 mm and a flatness ratio of 3-6.

5. The PP / PET alloy material according to claim 1, characterized in that, The compatibility agent is at least one of a maleic anhydride type compatibility agent, an epoxy type compatibility agent or a thermoplastic polyester-based elastomer.

6. The PP / PET alloy material according to claim 1, characterized in that, The PP / PET alloy material further comprises other auxiliary agents in an amount of 0.5-1.5 parts.

7. The method for preparing the PP / PET alloy material according to any one of claims 1-6, characterized in that, The PP / PET alloy material is prepared by mixing the components, melt extruding and granulating.

8. Use of the PP / PET alloy material according to any one of claims 1-6 in the preparation of an automobile part.

9. An automotive component characterised in that, The automobile part is prepared from the PP / PET alloy material according to claims 1-6.

10. The automotive component of claim 9, wherein, The automobile part is an off-road vehicle exterior part.

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