High-gloss spraying-free scratch-resistant PC / ASA / PMMA alloy and preparation method thereof

Abstract

The invention discloses a high-gloss spraying-free scratch-resistant PC / ASA / PMMA alloy and a preparation method thereof. The high-gloss spraying-free scratch-resistant PC / ASA / PMMA alloy is prepared from the following components: 60-80 parts of PC resin synthesized by a transesterification method, 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. Due to the fact that the refractive indexes of PC resin, PMMA resin and ASA resin are different, shell colors are generated on the surface of the PC / ASA / PMMA alloy, the dyeing performance and the scratch-resistant performance are affected, the refractive indexes are improved, the shell colors are eliminated and the dyeing performance of the PC / ASA / PMMA alloy is improved through a reactive refractive index modifier, and the scratch-resistant performance of the PC / ASA / PMMA alloy is improved through migration of 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 high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy and a preparation method thereof Background Art

[0002] 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 increasingly strong

[0003] In recent years, spray-free ASA / PMMA alloy materials such as Chinese Patent CN106832723A, Chinese Patent CN112745615A, etc. have obtained high-gloss spray-free ASA / PMMA materials through different methods. However, since the heat distortion temperature (1.8 MPa) 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 has improved the heat distortion temperature of ASA / PMMA by adding a heat-resistant agent additionally, it is still less than 110°C, seriously hindering 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 the refractive index of PMMA is 1.49, although both PC and PMMA have ester-based functional groups and have partial compatibility in theory, the difference in refractive index will cause the PC / PMMA alloy to exhibit a shell color. Chinese Patent CN111154252B obtains an alloy material by reacting PC and PMMA with 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] The present invention uses a refractive index improver and, in combination with a screw assembly, improves the refractive indices of PC and PMMA resins, and then forms an alloy with ASA resin to obtain a high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy material with a heat distortion temperature exceeding 120°C. This method is simple to operate and is particularly easy to industrialize Summary of the Invention

[0007] The present invention provides a preparation method of a high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy in view of the deficiencies of the prior art.

[0008] A high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy is prepared from the following raw materials by weight:

[0009] 60-80 parts of PC resin;

[0010] 5-10 parts of ASA high rubber powder;

[0011] 20-30 parts of PMMA resin;

[0012] 3-5 parts of refractive index modifier;

[0013] 0-1 part of antioxidant;

[0014] 0-0.05 part of lubricant;

[0015] 0-1 part of light stabilizer;

[0016] 1-3 parts of masterbatch.

[0017] In the above alloy material, 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 synthesis method of PC is the transesterification method, and the polydispersity index is 1.5-2.0.

[0018] 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.

[0019] 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.

[0020] The refractive index modifier is a copolymer of methacrylate containing highly active epoxy groups, and its epoxy content is 0.1-5%.

[0021] The copolymer of methacrylate with highly active epoxy groups in the refractive index modifier is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

[0022] The lubricant is one of pentaerythritol stearate, ethylene bis-stearamide, etc.

[0023] The antioxidant is at least two of antioxidant 1010, antioxidant 1076, antioxidant 618, antioxidant 619F, and antioxidant 168 used in combination.

[0024] The light stabilizers mentioned above are at least two kinds of light stabilizer 234, light stabilizer 5050H, light stabilizer 770, light stabilizer 328, etc. used in combination.

[0025] A preparation method of a high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy is characterized in that the preparation method comprises four steps:

[0026] (1) Prepare raw materials according to each component described in claim specification 1 and weigh the corresponding weights.

[0027] (2) Put the previously 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.

[0028] (3) Put the previously 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.

[0029] (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 scratch-resistant PC / ASA / PMMA alloy material through strand pelletization.

[0030] The twin-screw has two vacuum ports, which are 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.

[0031] The twin-screw cannot have reverse thread blocks after the 8th section, replace the kneading blocks and shear blocks with ZME. In particular, the number of ZME should not exceed 3.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention obtains a PC reaction through the reaction of highly active epoxy in the epoxy and methacrylate copolymer with transesterification. The methacrylate at the other end of the copolymer can be well compatible with PMMA, thereby achieving the effect of improving the refractive index of PC and PMMA. By strictly 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. Due to its high surface hardness, PMMA is given good scratch resistance. By selecting PMMA resin with high fluidity and high dispersion coefficient, the PMMA resin can migrate to the surface of the PC / ASA / PMMA alloy to improve the scratch 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

[0034] The following gives specific implementation examples of the present invention. The specific implementation examples are only used to further illustrate the present invention and do not limit the protection scope of the patent of this application.

[0035] The present invention provides a preparation method of a high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy, which is characterized in that the method comprises the following steps:

[0036] In the following examples, 60-80 parts of PC resin synthesized by the transesterification method are selected, the number average molecular weight is 30,000-50,000, the melt flow rate is 2-5, and the test conditions are 300 °C * 1.2 kg. Particularly, the synthesis method of PC is the transesterification method, and the polydispersity index is 1.5-2.0.

[0037] The ASA high rubber powder has a unimodal distribution, and the rubber particle size is 0.1-0.2 um.

[0038] The PMMA has a number average molecular weight of 25,000-40,000, a polydispersity coefficient of 5-8, and particularly a melt flow rate of 15-30.

[0039] The refractive index modifying agent is a methacrylate copolymer containing highly active epoxy groups. Particularly, the epoxy content is 0.1-5%, and the methacrylate copolymer with highly active epoxy groups in the refractive index modifying agent is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

[0040] The lubricant is one of pentaerythritol stearate, ethylene bis-stearamide, etc.

[0041] The antioxidants are at least two of antioxidant 1010, antioxidant 1076, antioxidant 618, antioxidant 619F, and antioxidant 168 used in combination.

[0042] The light stabilizers are at least two of light stabilizer 234, light stabilizer 5050H, light stabilizer 770, light stabilizer 328, etc. used in combination.

[0043] Example 1

[0044] (1) Weigh 65 parts of PC resin synthesized by the transesterification method 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.

[0045] (2) Weigh 5 parts of refractive index modifier as an epoxy and methyl methacrylate copolymer with an epoxy content of 1%, 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.

[0046] (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.

[0047] (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

[0048] Example 2

[0049] (1) Weigh 80 parts of PC resin synthesized by the transesterification method 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.

[0050] (2) Weigh 3 parts of refractive index modifier as an epoxy and methyl methacrylate copolymer with an epoxy content of 3%, 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.

[0051] (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.

[0052] (4) Feed mixture B into a twin-screw extruder through a solid metering pump. The number of ZME is 3, and the vacuum degree of the second vacuum port is -0.08 Mpa. The product is obtained through melt granulation.

[0053] Example 3

[0054] (1) Weigh 70 parts of PC resin synthesized by the transesterification method with a melt index of 5, 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 for mixing for 7 minutes to obtain mixture A.

[0055] (2) Weigh 2 parts of refractive index modifier, which is a copolymer of epoxy and methyl methacrylate with an epoxy content of 4%, and weigh 18 parts of PMMA resin with a melt index of 15, and put them into a mixer for mixing for 7 minutes to obtain mixture B.

[0056] (3) Feed 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 at 45 degrees.

[0057] (4) Feed mixture B into a twin-screw extruder through a solid metering pump. The number of ZME is 3, and the vacuum degree of the second vacuum port is -0.08 Mpa. The product is obtained through melt granulation.

[0058] Example 4

[0059] (1) Weigh 60 parts of PC resin synthesized by the transesterification method with a melt index of 5, 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 3 parts of black masterbatch, and put them into a mixer for mixing for 7 minutes to obtain mixture A.

[0060] (2) Weigh 2 parts of refractive index modifier, which is a copolymer of epoxy and methyl methacrylate with an epoxy content of 4%, and weigh 28 parts of PMMA resin with a melt index of 20, and put them into a mixer for mixing for 7 minutes to obtain mixture B.

[0061] (3) Feed 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 at 45 degrees and 2 shear blocks at 30 degrees.

[0062] (4) Feed mixture B into a twin-screw extruder through a solid metering pump. The number of ZME is 4, and the vacuum degree of the second vacuum port is -0.08 Mpa. The product is obtained through melt granulation.

[0063] Comparative Example 1

[0064] (1) Weigh 65 parts of phosgene-process synthesized PC resin with a melt index of 3, 10 parts of ASA rubber powder with a rubber particle size of 0.15 μm, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch. Put them into a mixer and mix for 7 minutes to obtain mixture A.

[0065] (2) Weigh 25 parts of PMMA resin with a melt index of 20 and put it into a mixer and mix for 7 minutes to obtain mixture B.

[0066] (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, and it contains 3 shear blocks at 45 degrees and 1 shear block at 30 degrees.

[0067] (4) Put mixture B into a twin-screw extruder through a solid metering pump, with the number of ZME being 3 and the vacuum degree of the second vacuum port being -0.08 Mpa, and obtain the product through melt granulation.

[0068] Comparative Example 2

[0069] (1) Weigh 65 parts of phosgene-process synthesized PC resin with a melt index of 3, 10 parts of ASA rubber powder with a rubber particle size of 0.15 μm, 1 part of antioxidant, 1 part of light stabilizer, 0.5 part of lubricant, and 2 parts of black masterbatch. Put them into a mixer and mix for 7 minutes to obtain mixture A.

[0070] (2) Weigh 5 parts of refractive index modifier, which is an epoxy-methyl methacrylate copolymer with an epoxy content of 1%, 20 parts of PMMA resin with a melt index of 20, and put them into a mixer and mix for 7 minutes to obtain mixture B.

[0071] (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, and it contains 3 shear blocks at 45 degrees and 1 shear block at 30 degrees.

[0072] (4) Put mixture B into a twin-screw extruder through a solid metering pump, with the number of ZME being 3 and the vacuum degree of the second vacuum port being -0.08 Mpa, and obtain the product through melt granulation.

[0073] Comparative Example 3

[0074] (1) Weigh 65 parts of transesterification-process synthesized PC resin with a melt index of 3, 10 parts of ASA rubber powder with a rubber particle size of 0.15 μm, 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, which is an epoxy-methyl methacrylate copolymer with an epoxy content of 1%, 20 parts of PMMA resin with a melt index of 20, and put them into a mixer and mix for 7 minutes to obtain mixture A.

[0075] (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.

[0076] Comparative Example 4

[0077] (1) Weigh 65 parts of an ester-exchange synthesized PC resin with a melt index of 3, 10 parts of ASA rubber powder, the rubber particle size is 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 for mixing for 7 min to obtain mixture A.

[0078] (2) Weigh 5 parts of a refractive index modifier, which is a copolymer of epoxy and methyl methacrylate with an epoxy content of 1%, and 20 parts of PMMA resin with a melt index of 5, and put them into a mixer for mixing for 7 minutes to obtain mixture B.

[0079] (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 it contains 3 shear blocks at 45 degrees and 1 shear block at 30 degrees.

[0080] (4) Feed mixture B into a twin-screw extruder through a solid metering pump, the number of ZME is 3, and the vacuum degree of the second vacuum port is -0.08 Mpa, and obtain the product through melt granulation

[0081] 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 scratch resistance is judged according to 10 N in PV3952. The sample injection molding is a high-gloss plate with a polishing fineness of 20,000 meshes.

[0082] .

Claims

1. A high-gloss spray-free scratch-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 scratch-resistant PC / ASA / PMMA alloy according to claim 1, characterized in that: The number-average molecular weight of the described PC resin is 30,000 - 50,000, and the melt flow rate is 2 - 5, with the test conditions of 300 °C * 2.16 kg.

3. A high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy according to claim 2, characterized in that: The synthesis method of PC is the transesterification method, and the polydispersity index is 1.5 - 2.

0.

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

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

6. The high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy according to claim 1, characterized in that: The described refractive index modifier is a copolymer of methacrylate containing highly active epoxy groups, and its epoxy content is 0.1 - 5%.

7. A high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy according to claim 6, characterized in that: The copolymer of methacrylate with highly active epoxy groups in the described refractive index modifier is one or two copolymers of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

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

9. The preparation method of the high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy according to any one of claims 1-8, characterized in that Including the following steps: (1) Prepare raw materials according to each component described in claim specification 1 and weigh the corresponding weights; (2) Put the previously 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 previously 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 scratch-resistant PC / ASA / PMMA alloy material through strand pelletization.

10. The preparation method of the high-gloss spray-free scratch-resistant PC / ASA / PMMA alloy according to claim 9, characterized in that, The described twin-screw has two vacuum ports, respectively at the 6th and 9th sections of the extruder. Particularly, the number of reverse-threaded blocks before the 7th section cannot exceed 4, and particularly, the reverse-threaded blocks are mainly at 30 degrees and 45 degrees; There should be no reverse-threaded blocks after the 8th section of the described twin-screw, and replace the kneading blocks and shear blocks with ZME. Particularly, the number of ZME should not exceed 3.