High-gloss spraying-free high-weather-resistance PC / ASA / PMMA alloy and preparation method thereof

Abstract

The invention discloses a high-gloss spraying-free high-weather-resistant PC / ASA / PMMA alloy and a preparation method thereof. The high-gloss spraying-free high-weather-resistant PC / ASA / PMMA alloy is prepared from the following raw materials in parts by weight: 60-80 parts of PC resin, 5-10 parts of ASA high glue powder, 20-30 parts of PMMA resin, 3-5 parts of a refractive index modifier, 0-1 part of an antioxidant, 0-0.05 part of a lubricant, 0-1 part of a light stabilizer and 1-3 parts of color master batch. The shell color is generated on the surface of the PC / ASA / PMMA alloy due to the refractive index difference of the PC resin, the PMMA resin and the ASA resin, the dyeing performance is influenced, the refractive index of the PMMA is adjusted through the refractive index modifier, the shell color is eliminated, the dyeing performance of the PC / ASA / PMMA resin is improved, and the weather resistance of the PC / ASA / PMMA alloy is improved by migrating the PMMA resin with a high polydispersity coefficient to the surface of the PC / ASA / PMMA alloy; the stability of the PC / ASA / PMMA alloy is improved by optimizing the screw combination, and the method is easy to operate and particularly suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to the field of thermoplastic composites, and particularly to a preparation method of a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy. Background Art

[0002] In recent years, the consumption level has been increasing, and consumers' consumption concepts have gradually changed from practical to aesthetic and practical. At the same time, with the country's increasing emphasis on environmental protection and the cost reduction requirements of OEMs, the demand for spray-free materials is also becoming more and more vigorous.

[0003] In recent years, spray-free ASA / PMMA alloy materials have emerged in large numbers. Chinese Patent CN106832723A, Chinese Patent CN112745615A, etc. obtain high-gloss spray-free ASA / PMMA materials through different methods. However, since the Vicat softening temperature of pure PMMA is below 110°C, the heat distortion temperature of the alloy will inevitably decrease after toughening with ASA resin. Although Chinese Patent CN111690222A improves the Vicat softening temperature of ASA / PMMA by adding a heat-resistant agent, it is still less than 110°C, which seriously hinders the application space of the material.

[0004] The heat distortion temperature of PC can reach above 130°C. However, since the refractive index of PC is 1.58 and that of PMMA is 1.49, although both PC and PMMA have ester functional groups and have partial compatibility in theory, the difference in refractive index will cause the alloy made of PC and PMMA to show a shell color. Chinese Patent CN111154252B obtains an alloy material by reacting PC and PMMA through an ester exchange promoter. However, due to the introduction of the ester exchange promoter, the reaction process control is difficult, which will deteriorate the mechanical properties. Therefore, it is difficult for Chinese Patent CN111154252B to achieve a balance between mechanical properties and appearance properties.

[0005] Chinese Patent CN115926415A discloses a PC / ASA / PMMA ternary alloy material obtained by an ester exchange reaction between PC and PMMA. However, since the ester exchange reaction agent used is an oligomer, there is a risk of precipitation during long-term injection molding of parts, which will cause problems such as local whitening on the surface of the parts.

[0006] As is well known, the weather resistance of PC is very poor, and chemical bonds are particularly easy to break under long-term ultraviolet light irradiation, which has a great impact on the surface of the product. However, none of the above reports have reported on the weather resistance of the alloy.

[0007] Through a refractive index improver and in combination with a screw assembly, the present invention improves the refractive indices of PC and PMMA resins, and then forms an alloy with ASA resin. By having PMMA with a high polydispersity coefficient migrate to the resin surface to form a thin PMMA protective film, a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy material with a Vicat softening temperature exceeding 120 °C is obtained. This method is simple to operate and is particularly easy to industrialize. Summary of the Invention

[0008] The present invention provides a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy and a preparation method thereof in view of the deficiencies of the prior art.

[0009] A high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy is prepared from the following raw materials by weight:

[0010] 60 - 80 parts of PC resin;

[0011] 5 - 10 parts of ASA high rubber powder;

[0012] 20 - 30 parts of PMMA resin;

[0013] 3 - 5 parts of refractive index modifier;

[0014] 0 - 1 part of antioxidant;

[0015] 0 - 0.05 part of lubricant;

[0016] 0 - 1 part of light stabilizer;

[0017] 1 - 3 parts of masterbatch.

[0018] The number-average molecular weight of the PC resin is 30,000 - 50,000, the melt flow rate is 2 - 5, and the test conditions are 300 °C * 2.16 kg. In particular, the polydispersity index is 1.5 - 2.0.

[0019] The ASA is high rubber powder. In particular, the rubber powder has a unimodal distribution, and the rubber particle size is 0.1 - 0.2 μm.

[0020] The number-average molecular weight of the PMMA is 25,000 - 40,000, the polydispersity coefficient is 5 - 8, and in particular, the melt flow rate is 15 - 30.

[0021] The refractive index modification additive is a copolymer of styrene and methacrylate. In particular, the refractive index is 1.53 - 1.54.

[0022] The high-activity epoxy group methacrylic acid value copolymer in the refractive index modification additive is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

[0023] The lubricant is one of pentaerythritol stearate, ethylene bisstearamide, etc.

[0024] The antioxidant is at least two of antioxidant 1010, antioxidant 1076, antioxidant 618, antioxidant 619F, antioxidant 168 used in combination.

[0025] The light stabilizer is at least two of light stabilizer 234, light stabilizer 5050H, light stabilizer 770, light stabilizer 328, etc. used in combination.

[0026] A preparation method of a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy, characterized in that the preparation method comprises four steps:

[0027] (1) Prepare raw materials according to each component described in claim specification 1 and weigh the corresponding weights.

[0028] (2) Put the pre-weighed PC resin, ASA resin, antioxidant, light stabilizer, lubricant, and color masterbatch into a physical mixer, control the rotation speed at 100 - 800 rpm, and control the mixing time at 5 - 10 minutes to obtain a uniformly mixed material A.

[0029] (3) Put the pre-weighed PMMA resin and refractive index modifier into a physical mixer, control the rotation speed at 100 - 800 rpm, and control the mixing time at 5 - 10 minutes to obtain a uniformly mixed material B.

[0030] (4) Add the uniformly mixed material A to a twin-screw extruder through a metering pump, control the screw rotation speed at 300 - 800 rmp, control the temperature within the range of 230 - 260 °C, then add material B through side feeding, and obtain a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy material through strand pelletization.

[0031] The twin-screw has two vacuum ports, respectively at the 6th and 9th sections of the extruder. In particular, the number of reverse thread blocks before the 7th section cannot exceed 4, and in particular, the reverse thread blocks are mainly at 30 degrees and 45 degrees.

[0032] There cannot be reverse thread blocks after the 8th section of the twin-screw, and the kneading blocks and shear blocks are replaced with ZME. In particular, the number of ZME should not exceed 3.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In the present invention, the styrene-methacrylate copolymer has a refractive index close to that of PMMA and a very high compatibility with PMMA, thereby achieving the effect of improving the refractive index of PC and PMMA; by controlling the particle size of the rubber powder in the ASA resin, the influence of the ASA resin on the refractive index of the system can be made small; PMMA is endowed with good weather resistance due to the presence of its acrylate. By selecting a PMMA resin with high fluidity and high dispersion coefficient, the PMMA resin can migrate to the surface of the PC / ASA / PMMA alloy to form a thin film, improving the weather resistance of PC / ASA / PMMA; on the other hand, the PMMA resin is very sensitive to temperature and shear. Excessive temperature will cause PMMA degradation. By adding PMMA through side feeding and re-combining the screw after side feeding, replacing the shear block with high shear strength with a dispersion block with good dispersion effect to reduce PMMA degradation, a high-gloss PC / ASA / PMMA alloy material with stable performance is obtained. The preparation method of the PC / ASA / PMMA alloy material provided by the present invention is simple and is particularly suitable for industrial mass production. Detailed implementation mode

[0035] The following gives specific implementation examples of the present invention. The specific embodiments are only used to further illustrate the present invention and do not limit the protection scope of the patent of this application.

[0036] The present invention provides a method for preparing a high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy, which is characterized in that the method comprises the following steps:

[0037] In the following examples, 60-80 parts of PC resin are selected, the number-average molecular weight is 30,000-50,000, the melt flow rate is 2-5, the test conditions are 300 °C * 1.2 kg, and in particular, the polydispersity index is 1.5-2.0.

[0038] The ASA high rubber powder has a unimodal distribution, and the rubber particle size is 0.1-0.2 μm.

[0039] The PMMA number-average molecular weight is 25,000-40,000, the polydispersity coefficient is 5-8, and in particular, the melt flow rate is 15-30.

[0040] The refractive index modifying agent is a copolymer of styrene and methacrylate. In particular, the refractive index is 1.53-1.54, and the high-activity epoxy group methacrylate copolymer in the refractive index modifying agent is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

[0041] The lubricant is one of pentaerythritol stearate, ethylene bis-stearamide, etc.

[0042] The antioxidants are at least two of antioxidant 1010, antioxidant 1076, antioxidant 618, antioxidant 619F, and antioxidant 168 used in combination.

[0043] The light stabilizers are at least two of light stabilizer 234, light stabilizer 5050H, light stabilizer 770, light stabilizer 328, etc. used in combination.

[0044] Example 1

[0045] (1) Weigh 65 parts of PC resin with a melt index of 3, 10 parts of ASA powder, the rubber particle size is 0.15um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0046] (2) Weigh 5 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, and weigh 20 parts of PMMA resin with a melt index of 20, and put them into a mixer to mix for 7 minutes to obtain mixture B.

[0047] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature is 230 - 260 °C, the vacuum degree is controlled at -0.08 Mpa, and it contains 3 shear blocks of 45 degrees and 1 shear block of 30 degrees.

[0048] (4) Put mixture B into a twin-screw extruder through a solid metering pump, the number of ZME is 3, the vacuum degree of the second vacuum port is -0.08 Mpa, and the product is obtained through melt granulation.

[0049] Example 2

[0050] (1) Weigh 80 parts of PC resin with a melt index of 3, 5 parts of ASA powder, the rubber particle size is 0.15um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0051] (2) Weigh 3 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, and weigh 12 parts of PMMA resin with a melt index of 30, and put them into a mixer to mix for 7 minutes to obtain mixture B.

[0052] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature is 230 - 260 °C, the vacuum degree is controlled at -0.08 Mpa, and it contains 4 shear blocks of 45 degrees.

[0053] (4) Put mixture B into a twin-screw extruder through a solid metering pump, the number of ZME is 3, the vacuum degree of the second vacuum port is -0.08 Mpa, and the product is obtained through melt granulation.

[0054] Example 3

[0055] (1) Weigh 70 parts of PC resin with a melt index of 5, 10 parts of ASA powder, rubber particle size of 0.15um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0056] (2) Weigh 2 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, and weigh 18 parts of PMMA resin with a melt index of 15, and put them into a mixer to mix for 7 minutes to obtain mixture B.

[0057] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature is 230 - 260°C, the vacuum degree is controlled at -0.08 Mpa, and it contains 4 shear blocks of 45 degrees.

[0058] (4) Put mixture B into a twin-screw extruder through a solid metering pump, the number of ZME is 3, the vacuum degree of the second vacuum port is -0.08 Mpa, and obtain the product through melt granulation

[0059] Example 4

[0060] (1) Weigh 60 parts of PC resin with a melt index of 5, 10 parts of ASA powder, rubber particle size of 0.15um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 3 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0061] (2) Weigh 2 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, and weigh 28 parts of PMMA resin with a melt index of 20, and put them into a mixer to mix for 7 minutes to obtain mixture B.

[0062] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature is 230 - 260°C, the vacuum degree is controlled at -0.08 Mpa, and it contains 2 shear blocks of 45 degrees and 2 shear blocks of 30 degrees.

[0063] (4) Put mixture B into a twin-screw extruder through a solid metering pump, the number of ZME is 4, the vacuum degree of the second vacuum port is -0.08 Mpa, and obtain the product through melt granulation

[0064] Comparative Example 1

[0065] (1) Weigh 65 parts of PC resin with a melt index of 3, 10 parts of ASA rubber powder, with a rubber particle size of 0.15 um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0066] (2) Weigh 25 parts of PMMA resin with a melt index of 20, and put it into a mixer to mix for 7 minutes to obtain mixture B.

[0067] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature at 230 - 260 °C, the vacuum degree at -0.08 Mpa, with 3 shear blocks at 45 degrees and 1 shear block at 30 degrees.

[0068] (4) Put mixture B into a twin-screw extruder through a solid metering pump, with the number of ZME being 3, the vacuum degree of the second vacuum port at -0.08 Mpa, and obtain the product through melt granulation.

[0069] Comparative Example 2

[0070] (1) Weigh 65 parts of PC resin with a melt index of 3, 10 parts of ASA rubber powder, with a rubber particle size of 0.15 um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0071] (2) Weigh 5 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, weigh 20 parts of PMMA resin with a melt index of 3, and put them into a mixer to mix for 7 minutes to obtain mixture B.

[0072] (3) Put mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature at 230 - 260 °C, the vacuum degree at -0.08 Mpa, with 3 shear blocks at 45 degrees and 1 shear block at 30 degrees.

[0073] (4) Put mixture B into a twin-screw extruder through a solid metering pump, with the number of ZME being 3, the vacuum degree of the second vacuum port at -0.08 Mpa, and obtain the product through melt granulation.

[0074] Comparative Example 3

[0075] (1) Weigh 65 parts of PC resin with a melt index of 3, 10 parts of ASA rubber powder, with a rubber particle size of 0.15 um, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, 2 parts of black masterbatch, 5 parts of refractive index modifier as a copolymer of styrene and methyl methacrylate with a refractive index of 1.535, weigh 20 parts of PMMA resin with a melt index of 20, and put them into a mixer to mix for 7 minutes to obtain mixture A.

[0076] (3) Feed mixture A into a twin-screw extruder through a solid metering pump, control the screw speed at 500 rpm, the extrusion temperature at 230 - 260 °C, and the vacuum degree at -0.08 Mpa, and obtain the product through melt granulation.

[0077] Dry the granulated particles, take samples for testing. The notched impact performance test is carried out in accordance with ISO 179-1, the Vicat softening temperature is in accordance with ISO 306 (B50), and the light resistance is judged for the external light and gray scale level in accordance with SAE J2527 2500 KJ. The sample injection molding is a high-gloss plate with a polishing fineness of 20,000 meshes.

[0078]

[0079]

Claims

1. A high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy, characterized in that, Prepared from the following raw materials by weight parts: 60 - 80 parts of PC resin; 5 - 10 parts of ASA high rubber powder; 20 - 30 parts of PMMA resin; 3 - 5 parts of refractive index modifier; 0 - 1 part of antioxidant; 0 - 0.05 part of lubricant; 0 - 1 part of light stabilizer; 1 - 3 parts of masterbatch.

2. The high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 1, wherein: The number average molecular weight of the PC resin is 30,000 - 50,000, the melt flow rate is 2 - 5, the test conditions are 300 °C * 2.16 kg, and the polydispersity index is 1.5 - 2.

0.

3. A high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 1, characterized in that: The ASA is high rubber powder, the rubber powder has a unimodal distribution, and the rubber particle size is 0.1 - 0.2 um.

4. A high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 1, characterized in that: The number average molecular weight of the PMMA is 25,000 - 40,000, the polydispersity coefficient is 5 - 8, and the melt flow rate is 15 - 30.

5. A high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 1, characterized in that: The refractive index modifying additive is a copolymer of styrene and methacrylate, and the refractive index is 1.53 - 1.

54.

6. The high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 5, characterized in that: The high - activity epoxy - group - containing methacrylic acid - value copolymer in the refractive index modifying additive is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

7. The high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 1, wherein: The lubricant is one of pentaerythritol stearate, ethylene bisstearamide, etc.; the antioxidant is at least two of antioxidant 1010, antioxidant 1076, antioxidant 618, antioxidant 619F, antioxidant 168 used in combination; the light stabilizer is at least two of light stabilizer 234, light stabilizer 5050H, light stabilizer 770, light stabilizer 328, etc. used in combination.

8. The preparation method of the high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to any one of claims 1-7, characterized in that, The steps are as follows: (1) Prepare raw materials according to each component described in claim specification 1 and weigh the corresponding weights; (2) Put the pre - weighed PC resin, ASA resin, antioxidant, light stabilizer, lubricant, and masterbatch into a physical mixer, control the rotation speed at 100 - 800 rpm, and control the mixing time at 5 - 10 minutes to obtain a uniformly mixed material A; (3) Put the pre - weighed PMMA resin and refractive index modifier into a physical mixer, control the rotation speed at 100 - 800 rpm, and control the mixing time at 5 - 10 minutes to obtain a uniformly mixed material B; (4) Add the uniformly mixed material A into a twin - screw extruder through a metering pump, control the screw rotation speed at 300 - 800 rmp, control the temperature within the range of 230 - 260 °C, then add material B through side feeding, and obtain a high - gloss spray - free and high - weather - resistant PC / ASA / PMMA alloy material through strand pelletizing.

9. The preparation method of the high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 8, characterized in that: The twin - screw has two vacuum ports, which are respectively in the 6th and 9th sections of the extruder. Particularly, the number of reverse - thread blocks before the 7th section cannot exceed 4, and particularly, the reverse - thread blocks are mainly at 30 degrees and 45 degrees.

10. The preparation method of the high-gloss spray-free and highly weather-resistant PC / ASA / PMMA alloy according to claim 8, characterized in that: There should be no reverse - thread blocks after the 8th section of the twin - screw, and replace the kneading blocks and shear blocks with ZME. Particularly, the number of ZME should not exceed 3.

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