A recycled polypropylene composite material, a preparation method and application thereof

Abstract

The application discloses a recycled polypropylene composite material and a preparation method and application thereof. The recycled polypropylene composite material comprises the following components in parts by weight: 50-90 parts of recycled polypropylene resin; 5-30 parts of polypropylene resin B; and 0.1-0.8 parts of rheological agent. The EPR content in the polypropylene resin B is not less than 28 wt%. The one-minute half-life temperature of the rheological agent is not higher than 210 DEG C. The fluorescent intensity of the recycled polypropylene resin at 380 nm-420 nm is 4000-6500. The recycled polypropylene composite material has the advantages of effectively improving the paint adhesion and having better mechanical properties by compounding the recycled polypropylene resin with a specific fluorescent intensity, the rheological agent with a one-minute half-life temperature not higher than 210 DEG C and the polypropylene resin B with an EPR content not less than 28 wt%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polypropylene composite materials, and more particularly to a recycled polypropylene composite material, a preparation method thereof and an application thereof. BACKGROUND

[0002] Polypropylene resin is one of the three general-purpose plastics, and has been widely used in many fields such as household appliances, automobiles, power tools, packaging, building materials and furniture, etc. due to its wide source, low cost, low density, easy molding and other advantages.

[0003] With the enhancement of environmental awareness and the increasing scarcity of resources, the recycling of recycled plastics has become an important research topic in the world-wide "low-carbon economy" trend. However, recycled polypropylene resin (rPP) is easily affected by factors such as light, heat degradation, oxidation, etc. during long-term use and recycling, resulting in performance degradation, for example, there are problems such as blistering and peeling when used in spraying parts. SUMMARY

[0004] The present application aims to overcome the defects or deficiencies of the prior art, such as blistering and peeling, when recycled polypropylene resin is used in spraying parts, and to provide a recycled polypropylene composite material.

[0005] Another object of the present application is to provide a preparation method of the recycled polypropylene composite material.

[0006] Another object of the present application is to provide an application of the recycled polypropylene composite material.

[0007] To achieve the above-mentioned objects, the present application realizes the following technical solutions:

[0008] A recycled polypropylene composite material, comprising the following components calculated by weight parts:

[0009] recycled polypropylene resin 50-90 parts;

[0010] polypropylene resin B 5-30 parts;

[0011] rheological agent 0.1-0.8 parts;

[0012] wherein the EPR content in the polypropylene resin B is not less than 28wt%; the one-minute half-life temperature of the rheological agent is not higher than 210℃; and the fluorescence intensity of the recycled polypropylene resin at 380nm-420nm is 4000-6500.

[0013] In the present application, by adding polypropylene resin B with specific EPR content and rheological agent into the recycled polypropylene resin, the adhesion sites of paint molecules are increased by the polar groups generated during the aging process of the recycled polypropylene resin, and the exposure area of the ethylene segment on the surface of the composite is increased by the micro-crosslinking effect of the ethylene segment under the action of the rheological agent, which can effectively provide favorable sites and improve the paint adhesion of the recycled polypropylene composite.

[0014] Specifically, the polar group content of the recycled polypropylene resin is related to the aging degree; the aging degree of the recycled polypropylene resin is tested by fluorescence spectroscopy, which reflects the aging degree of the polypropylene molecular chain itself. The longer the emission wavelength, the greater the degree of conjugation of the polypropylene molecular chain (the greater the degree of molecular aging), the higher the fluorescence intensity, and the more the number of conjugated molecular chains (the greater the number of aged molecules).

[0015] Further, the fluorescence emission wavelength of the recycled polypropylene resin is 380-420 nm, and the fluorescence intensity is 4000-6500.

[0016] It should be noted that the content of the recycled polypropylene resin in the composite is preferably not less than 40wt%.

[0017] The fluorescence intensity of the recycled polypropylene resin in the present application is 4000-6500 at 380-420 nm, for example, but not limited to 4000, 4200, 4500, 4800, 5000, 5200, 5500, 5800, 6000, 6200 or 6500, etc. can achieve the present application. Further, the fluorescence intensity is 4200-6300.

[0018] The EPR content in the polypropylene resin B in the present application is not less than 28wt%, for example, but not limited to not less than 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt% or 45wt% etc. can achieve the present application. Further, the EPR content in the polypropylene resin B is 35wt%-45wt%.

[0019] Specifically, the EPR content is determined by gel permeation chromatography.

[0020] It should be noted that the one-minute half-life temperature of the rheological agent in the present application is not higher than 210 DEG C, for example but not limited to not higher than 210 DEG C, 205 DEG C, 200 DEG C, 195 DEG C, 190 DEG C, 185 DEG C, 180 DEG C, 175 DEG C, 170 DEG C or 165 DEG C, etc. can achieve the present application. Further, the one-minute half-life temperature of the rheological agent is 170-190 DEG C.

[0021] Further, the one-minute half-life temperature of the rheological agent is 180-184 DEG C.

[0022] Specifically, the one-minute half-life temperature measurement method of the rheological agent is electrochemical method.

[0023] Further, the rheological agent is an organic peroxide.

[0024] Further, the rheological agent is tert-butyl peroxide.

[0025] Specifically, the rheological agent is one or several of di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, di(tert-butylperoxy isopropyl)benzene.

[0026] It should be noted that the polypropylene resin B in the present application is 5-30 parts, for example but not limited to 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts or 30 parts, etc. can achieve the present application.

[0027] The rheological agent in the present application is 0.1-0.8 parts, for example but not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts or 0.8 parts, etc. can achieve the present application.

[0028] Further, the recycled polypropylene composite material comprises the following components calculated by weight parts:

[0029] Recycled polypropylene resin 58-80 parts;

[0030] Polypropylene resin B 10-25 parts;

[0031] Rheological agent 0.2-0.5 parts.

[0032] Further, the recycled polypropylene composite material comprises the following components calculated by weight parts:

[0033] Recycled polypropylene resin 60-65 parts;

[0034] Polypropylene resin B 15-20 parts;

[0035] Rheological agent 0.3-0.5 parts.

[0036] Further, the recycled polypropylene resin is obtained by recycling, processing and granulating waste plastic products in life or industry, wherein the EPR content is less than 10wt%.

[0037] Further, the recycled polypropylene resin has a melt flow rate of 20-40g / 10min under a load of 2.16kg at 230℃.

[0038] Further, the polypropylene resin B has a melt flow rate of 0.5-40g / 10min under a load of 2.16kg at 230℃.

[0039] Specifically, the test standard of the melt flow rate is ISO 1133-1-2022.

[0040] Further, the recycled polypropylene composite material further comprises 5-20 parts of a filler, 2-10 parts of a toughening agent, and 0.1-5 parts of an auxiliary agent.

[0041] Further, the filler comprises one or more of talc, calcium carbonate, wollastonite or mica.

[0042] Further, the toughening agent comprises one or more of ethylene-butene copolymer, ethylene-octene copolymer or hydrogenated styrene-butadiene block copolymer.

[0043] Further, the auxiliary agent comprises one or more of carbon black, light stabilizer or antioxidant.

[0044] Specifically, it comprises 0.5-2 parts of carbon black, 0.1-0.5 parts of light stabilizer, and 0.2-1 parts of antioxidant.

[0045] Further, the carbon black is a polyvinyl carbon black master batch.

[0046] The light stabilizer in the present application can be selected from commonly used light stabilizers, such as but not limited to hindered amine light stabilizers, benzotriazole light stabilizers or benzophenone light stabilizers.

[0047] The antioxidant in the present application can be selected from commonly used antioxidants, such as but not limited to hindered phenol antioxidants and / or phosphite antioxidants.

[0048] Specifically, the hindered phenolic antioxidant is one or more of N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide (Irganox 1098), tetra(beta-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid) pentaerythritol ester (Irganox 1010), triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (Iragnox 245), n-octadecyl beta-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Iragnox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-1,1-dimethyl}-2,4,8,10-tetraoxaspiro[undecane] (ADK AO-80).

[0049] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite (PEP-36), or 627A.

[0050] The application also protects a preparation method of the above-mentioned recycled polypropylene composite material, comprising the following steps:

[0051] The components are uniformly mixed, melt blended, extruded and granulated by an extruder to obtain the recycled polypropylene composite material.

[0052] Specifically, the components are uniformly mixed by a high-speed mixer, the mixing time is 1-3 min, and the mixing speed is 1000 rpm.

[0053] Specifically, the extruder is a double-screw extruder.

[0054] Specifically, the temperature of the first zone of the double-screw extruder is 60-120 DEG C, the temperature of the second zone to the fourth zone is 190-220 DEG C, and the temperature of the fifth zone to the tenth zone is 180-220 DEG C; and the rotating speed of the double-screw extruder is 300-500 rpm.

[0055] The application also protects the application of the above-mentioned recycled polypropylene composite material in automobile accessories, especially in paint-sprayed parts, such as automobile bumpers, automobile side skirts, wheel arches, lower trim panels and the like.

[0056] Compared with the prior art, the application has the following beneficial effects:

[0057] The application provides a recycled polypropylene composite material, which is prepared by adding polypropylene resin B with an EPR content of not less than 28 wt% and a rheological agent with a one-minute half-life temperature of not higher than 210 DEG C into recycled polypropylene resin and adjusting the fluorescence intensity of the recycled polypropylene resin, so that the paint adhesion of the recycled polypropylene composite material can be effectively improved, and the recycled polypropylene composite material has good impact strength. DETAILED DESCRIPTION

[0058] The application will be further described in conjunction with specific embodiments, but the embodiments do not limit the application in any form. Unless otherwise specified, the raw materials used in the embodiments of the application are commercially available raw materials.

[0059] 1. Raw materials used in each embodiment and comparative example:

[0060] Regenerated polypropylene resin:

[0061] Regenerated polypropylene resin 1: washing machine barrel polypropylene regenerated material, RPP DCT-1121PW72(SX), melt flow rate at 230℃ under a load of 2.16 kg is 35 g / 10 min, emission wavelength is 390 nm, fluorescence intensity is 4500, purchased from Chengdu Suxin;

[0062] Regenerated polypropylene resin 2: washing machine barrel polypropylene regenerated material, RPP DCM-1124PN52(GR), melt flow rate at 230℃ under a load of 2.16 kg is 25 g / 10 min, emission wavelength is 410 nm, fluorescence intensity is 6300, purchased from Changhong Gelun;

[0063] Regenerated polypropylene resin 3: washing machine barrel polypropylene regenerated material, RPP DCT-1121PW72(DW), melt flow rate at 230℃ under a load of 2.16 kg is 38 g / 10 min, emission wavelength is 430 nm, fluorescence intensity is 6700, purchased from Jieshou Dongwei;

[0064] Regenerated polypropylene resin 4: washing machine barrel polypropylene regenerated material, RPP DCT-1121PW72(GR), melt flow rate at 230℃ under a load of 2.16 kg is 36 g / 10 min, emission wavelength is 370 nm, fluorescence intensity is 3900, purchased from Changhong Gelun; Polypropylene resin B:

[0065] Polypropylene resin B1: PP NS06, EPR content is 45 wt%, purchased from China-Korea Petrochemical;

[0066] Polypropylene resin B2: PP LH-KA30, EPR content is 40 wt%, purchased from Lihe Zhixin;

[0067] Polypropylene resin B3: PP EP246P, EPR content is 35 wt%, purchased from Basel;

[0068] Polypropylene resin B4: PP SP 179, EPR content is 24 wt%, purchased from Lanzhou Petrochemical;

[0069] Rheological agent:

[0070] Rheological agent 1: di(tert-butylperoxy isopropyl) benzene, one-minute half-life temperature of 182℃, purchased from Shanghai Bojing Rheological agent 2: di-tert-butyl peroxide, one-minute half-life temperature of 186℃, purchased from Aldrich;

[0071] Rheological agent 3: 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane, one-minute half-life temperature of 179℃, purchased from AkzoNobel;

[0072] Rheological agent 4: tert-butyl hydroperoxide, one-minute half-life temperature of 223℃, purchased from AkzoNobel;

[0073] Filling agent: talcum powder, TY90-20-A, purchased from Dongguan Sanzhi;

[0074] Toughening agent: ethylene-butene copolymer, POE ENGAGE 7447, purchased from Dow Chemical;

[0075] Auxiliary agent:

[0076] Black: polyethylene carbon black masterbatch, PE2718, commercially available;

[0077] Light stabilizer: hindered amine light stabilizer, commercially available;

[0078] Antioxidant: a compound of hindered phenol antioxidant and phosphite antioxidant in a mass ratio of 1:1, both commercially available.

[0079] It should be noted that the same raw materials are used in the parallel experiments of the examples and the comparative examples of the present application.

[0080] 2. The recycled polypropylene composite materials in each example and comparative example are prepared according to the formulations in Tables 1-2 by the following method:

[0081] The components are placed in a high-speed mixer in proportion and mixed uniformly, the mixing time is 1-3 min, the mixing speed is 1000 rpm, and then fed into a twin-screw extruder for melt blending and extrusion granulation to obtain the recycled polypropylene composite material; wherein the temperature of the first zone of the twin-screw extruder is 90℃, the temperature of the second zone to the fourth zone is 205℃, and the temperature of the fifth zone to the tenth zone is 190℃, and the rotating speed of the twin-screw extruder is 400 rpm.

[0082] 3. Performance test:

[0083] (1) Spray adhesion test: the recycled polypropylene composite materials prepared in each example and comparative example are painted into a square plate of 100mm*100mm*2mm, flame treated before painting, and baked at 80℃ for 40min for solidification after painting;

[0084] a. Boiling water test: the above treated sample is placed in a constant temperature water bath at 40°C and soaked for 240h, and the surface blistering is observed. The adhesion is evaluated by the presence or absence of bubbles and their size. The more and larger the bubbles, the worse the adhesion. The evaluation levels are as follows: none, bubbles, slight small pimples, and severe small pimples. The surface without any blister is none; the surface with bubbles with a diameter of ≥0.1mm is called blistering; the surface with bubbles with a diameter of <0.1mm and the number of small pimples on the unit area (1cm 2 ) of <10 is slight small pimples; and the surface with bubbles with a diameter of <0.1mm and the number of small pimples on the unit area (1cm 2 ) of ≥10 is severe small pimples.

[0085] b. Crosshatch test: the above treated sample is tested according to the GB / T 9286-2021 standard. Specifically, the edge of the line is smooth, and there is no paint falling off at the edge and intersection of the line, which is 5B; there are small pieces of paint falling off at the intersection of the line, and the total area of falling off is less than 5%, which is 4B; there are small pieces of paint falling off at the edge and intersection of the line, and the total area of falling off is between 5% and 15%, which is 3B; there are pieces of paint falling off at the edge and intersection of the line, and the total area of falling off is between 15% and 35%, which is 2B; there are pieces of paint falling off at the edge and intersection of the line, and the total area of falling off is between 35% and 65%, which is 1B; and the falling off area exceeds the 1B standard, which is 0B.

[0086] (2) Notched Izod impact strength (23°C) test: the polypropylene composite material prepared in each example and comparative example is tested according to the ISO 180-2023 standard.

[0087] Examples 1-15 and Comparative Examples 1-5

[0088] Table 1: Amounts (unit: weight parts) and properties of each component in the recycled polypropylene composite material in Examples 1-9

[0089]

[0090]

[0091] Table 2: Amounts (unit: weight parts) and properties of each component in the recycled polypropylene composite material in Examples 10-15 and Comparative Examples 1-5

[0092]

[0093]

[0094] The prepared recycled polypropylene composite material has good paint adhesion and impact strength, specifically: only slight small pimples or no bubbles are generated after water boiling test after paint spraying; the grid test is not lower than 4B, and the impact strength is not lower than 20 KJ / m 2 .

[0095] It can be seen from the comparative example 1 that if no rheological agent is added, even if the EPR content in the added polypropylene resin B is adjusted, the paint adhesion of the prepared recycled polypropylene composite material is poor.

[0096] It can be seen from the comparative example 2 that if the EPR content in the added polypropylene resin B is too low, even if a specific rheological agent is added, the paint adhesion of the prepared recycled polypropylene composite material is poor, and the impact strength is obviously decreased.

[0097] It can be seen from the comparative example 3 that if the one-minute half-life temperature of the used rheological agent is too high, the paint adhesion of the prepared recycled polypropylene composite material is obviously decreased.

[0098] It can be seen from the comparative examples 4 and 5 that if the fluorescence intensity of the used recycled polypropylene resin is too low or too high, the comprehensive performance of the prepared recycled polypropylene composite material is obviously decreased.

[0099] Obviously, the above examples of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. On the basis of the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A recycled polypropylene composite material, characterized by, Comprise the following components by weight parts: 50~90 parts of recycled polypropylene resin; 5~30 parts of polypropylene resin B; 0.1~0.8 parts of rheological agent; Wherein, the EPR content in the polypropylene resin B is not less than 28wt%; the rheological agent is organic peroxide, the one-minute half-life temperature of the rheological agent is not higher than 210℃; the fluorescence intensity of the recycled polypropylene resin at 380nm~420nm is 4000~6500.

2. The recycled polypropylene composite material according to claim 1, characterized in that, The EPR content in the polypropylene resin B is 35wt%~45wt%.

3. The recycled polypropylene composite of claim 1, wherein, The one-minute half-life temperature of the rheological agent is 170~190℃.

4. The recycled polypropylene composite of claim 1, wherein, The EPR content in the recycled polypropylene resin is less than 10wt%.

5. The recycled polypropylene composite of claim 1, wherein, Also comprise 5~20 parts of filler, 2~10 parts of toughening agent, 0.1~5 parts of auxiliary agent.

6. The recycled polypropylene composite of claim 5, wherein, The filler includes one or several of talc, calcium carbonate, wollastonite or mica.

7. The recycled polypropylene composite of claim 5, wherein, The toughening agent includes one or several of ethylene-butene copolymer, ethylene-octene copolymer or hydrogenated styrene-butadiene block copolymer.

8. The recycled polypropylene composite of claim 5, wherein, The auxiliary agent includes one or several of carbon black, light stabilizer or antioxidant.

9. A process for the preparation of the recycled polypropylene composite material according to any one of claims 1 to 8, characterized in that, Comprise the following steps: Mixing the components uniformly, melt blending, extruding and granulating by extruder to obtain the recycled polypropylene composite material.

10. The use of the recycled polypropylene composite material according to any one of claims 1~8 in the preparation of automobile parts.

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