Halogen-free and fluorine-free high-flowing laser-engravable flame-retardant PC composite material and preparation method thereof

Abstract

The present application relates to a kind of high flowability of halogen-free fluorine-free laserable flame-retardant PC composite material and its preparation method, the PC composite material is prepared raw material including the following components according to mass fraction: polycarbonate 50-99.9 parts;Toughening agent 1-10 parts;Flame retardant 0.2-10 parts;Anti-dripping agent 0.05-2 parts;Antioxidant 0.05-5 parts;Color powder 0.05-2 parts;Laserable powder 0.05-2 parts.The PC composite material provided by the present application has good flame retardancy and flowability, and the laserable effect is good, and avoid using halogen-containing adjuvant and PFAS material, belong to environment-friendly type.

Description

Technical Field

[0001] This invention relates to the field of polycarbonate composite materials technology, specifically to a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material and its preparation method. Background Technology

[0002] Per- and polyfluoroalkyl substances (PFAS) are a class of chemicals widely used in adhesives, coatings, inks, and plastics due to their water and oil repellency, chemical resistance, and heat resistance. However, some PFAS materials can persist in the environment for extended periods and accumulate in organisms, potentially causing a range of health problems.

[0003] Polycarbonate (PC) is a high-molecular-weight polymer containing carbonate groups in its molecular chain, possessing excellent comprehensive properties, including mechanical properties, dimensional stability, flowability, heat resistance, ultraviolet (UV) resistance, and electrical properties. PC material itself has a UL94V-2 flame retardant rating and drips when exposed to fire. Its engineering plastic materials are widely used in the glass assembly industry, automotive industry, business communication equipment, and electronics and electrical appliance industries. In actual production and applications, to meet specific needs such as toughening, improving molding and processing performance, reducing residual deformation, and enhancing flame retardancy, PC usually requires modification treatment.

[0004] Currently, many mobile phone charger casings are made of flame-retardant PC plastic. With advancements in laser engraving technology and increased consumer acceptance, more and more chargers and power supply casings are using laser engraving to mark logos, graphics, fonts, and product instructions. However, due to the limitations of the PC plastic substrate, laser engraving may result in blurry graphics and low readability.

[0005] Therefore, providing a PC composite material with good comprehensive properties such as flame retardancy, toughness, and flowability, good laser engraving effect, and without the use of PFAS materials is a technical problem that needs to be solved in this field. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. Compared with the existing technology, the PC composite material provided by this invention has good flame retardancy and flowability, good laser engraving effect, and avoids the use of halogen-containing additives and PFAS materials, which is environmentally friendly.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material, wherein the PC composite material comprises the following components by mass parts:

[0009]

[0010] The PC composite material provided by this invention, through the compounding of polycarbonate, toughening agent, flame retardant, anti-dripping agent, antioxidant, colorant, and laser engraving powder, exhibits excellent flame retardancy and flowability, achieving flame retardant performance and fire resistance rating requirements at a thickness of ≥1.6mm, and can be used in ultra-thin parts, reducing the difficulty of injection molding. Furthermore, the synergy between the colorant and laser engraving powder results in a smooth surface after laser engraving, clear lettering, and durable colorfastness, providing excellent laser engraving effects. The laser engraving powder also has a dyeing effect, reducing the amount of colorant added and lowering material costs. In addition, the PC composite material provided by this invention does not require the use of halogen-containing additives or PFAS materials, thus avoiding negative impacts on human health and the environment, meeting the requirements of green and environmentally friendly materials.

[0011] In this invention, the polycarbonate is 50-99.9 parts, for example, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, or 99.9 parts; the toughening agent is 1-10 parts, for example, 1 part, 2 parts, 4 parts, 6 parts, 8 parts, or 10 parts; the flame retardant is 0.2-10 parts, for example, 0.2 parts, 0.5 parts, 1 part, 2 parts, 4 parts, 6 parts, 8 parts, or 10 parts; and the anti-dripping agent is 0.05-2 parts, for example, 0.05 parts, 0.1 parts, 0.5 parts, 0.8 parts, or 1 part. One or two parts, antioxidant 0.05-5 parts, for example, 0.05 parts, 0.1 parts, 0.5 parts, 0.8 parts, 1 part, 2 parts, 4 parts or 5 parts, color powder 0.05-2 parts, for example, 0.05 parts, 0.1 parts, 0.5 parts, 0.8 parts, 1 part or 2 parts, laser engraving powder 0.05-2 parts, for example, 0.05 parts, 0.1 parts, 0.5 parts, 0.8 parts, 1 part or 2 parts, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0012] Preferably, the polycarbonate includes virgin polycarbonate and / or post-consumer recycled polycarbonate.

[0013] In this invention, the polycarbonate is preferably post-consumer recycled polycarbonate (PCR PC), whose recycling sources include waste plastics from daily production and life, such as drinking water bottles, CDs, lamp housings, etc. The general recycling method is physical, including sorting, grinding, cleaning and granulation of the recycling system. Using PCR PC helps to reduce plastic pollution, reduce carbon dioxide emissions and reduce energy consumption.

[0014] Preferably, the polycarbonate includes any one or a combination of at least two of the following: bisphenol A type polycarbonate, polyester type polycarbonate, organosilicon copolymer polycarbonate, cyclohexane bisphenol A type polycarbonate, and polycarbonate synthesized from bisphenol TMC.

[0015] Preferably, the melt mass flow rate of the polycarbonate at 300°C and 1.2 kg pressure is 4-70 g / 10 min, for example, it can be 4 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, 65 g / 10 min or 70 g / 10 min, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0016] Preferably, the polycarbonate has a weight-average molecular weight of 20,000-50,000, for example, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000 or 50,000, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] Preferably, the polycarbonate has a molecular weight distribution of 1-2.5, for example, it can be 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4 or 2.5, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] Preferably, the toughening agent comprises any one or a combination of at least two of the following: core-shell acrylate-PMMA toughening agents, core-shell acrylate-SAN toughening agents, core-shell silicone-PMMA toughening agents, core-shell silicone-SAN toughening agents, cross-linked methacrylate-methyl methacrylate toughening agents, butadiene-styrene-methyl methacrylate toughening agents, or silicone rubber-methyl methacrylate toughening agents.

[0019] The PC composite material provided by this invention, by adding toughening agents, can not only enhance flexibility, impact resistance, hydrolysis resistance and heat aging resistance, but also optimize processing performance. For example, in injection molding, extrusion and other processing, toughening agents can make the material flow more easily and fill the mold, thereby reducing processing difficulty and improving production efficiency. Therefore, the PC composite material provided by this invention can be used in ultra-thin parts to reduce the difficulty of injection molding.

[0020] Preferably, the flame retardant comprises a combination of phosphorus-based flame retardants, sulfonate-based flame retardants, and organosilicon-based flame retardants.

[0021] Preferably, the phosphorus-based flame retardant includes hypophosphite-based flame retardants and / or phosphate ester-based flame retardants.

[0022] Preferably, the hypophosphite-based flame retardant includes vinyl aluminum hypophosphite and / or vinyl hypophosphite.

[0023] Preferably, the phosphate ester flame retardant includes any one or a combination of at least two of the following: 1,3-phenylene phosphate (2,6-tolyl) tetraester flame retardant, tetraphenylbisphenol A diphosphate and its derivatives flame retardant, tetraphenylresorcinol diphosphate and its derivatives flame retardant, or triphenyl phosphate flame retardant.

[0024] Preferably, the sulfonate flame retardant includes any one or a combination of at least two of potassium benzenesulfonylbenzenesulfonate, potassium perfluorobutylsulfonate, or sodium 2,4,5-trichlorobenzenesulfonate.

[0025] Preferably, the organosilicon flame retardant includes any one or a combination of at least two of the following: polysiloxane and its derivative flame retardants, cross-linked polydimethylsiloxane and its derivative flame retardants, or methyl / phenyl organosilicon flame retardants.

[0026] Preferably, the mass ratio of phosphorus-based flame retardant, sulfonate-based flame retardant and organosilicon-based flame retardant in the flame retardant is (1-10):(0.2-10):(0.2-10), for example, it can be 1:0.2:0.2, 1:2:3, 2:5:7 or 10:9:10, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] In this invention, by preferably using flame retardants including phosphorus-based flame retardants, sulfonate-based flame retardants, and organosilicon-based flame retardants and controlling the mass ratio of the three, it is possible to further achieve the flame retardant requirements and fire resistance rating at a thickness of ≥1.6mm.

[0028] Preferably, the anti-dripping agent comprises fluorine-free nanoclay material.

[0029] In this invention, the fluorine-free nanoclay material may be, for example, montmorillonite.

[0030] In this invention, fluorine-free nano-clay material is preferably used as an anti-dripping agent, which has the characteristics of excellent char formation, halogen-free and fluorine-free, and environmentally friendly.

[0031] Preferably, the antioxidant includes any one or a combination of at least two of hindered phenolic antioxidants, hindered amine antioxidants, or phosphite antioxidants.

[0032] Preferably, the hindered phenolic antioxidant includes (β-3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl acrylate.

[0033] Preferably, the hindered amine antioxidant includes diphenylamine and its derivatives antioxidants and / or p-phenylenediamine antioxidants.

[0034] Preferably, the phosphite antioxidant includes tris(2,4-di-tert-butylphenyl) phosphite and / or pentaerythritol diphosphite.

[0035] Preferably, the antioxidant comprises a combination of hindered phenolic antioxidants and phosphite antioxidants.

[0036] Preferably, the mass ratio of the hindered phenolic antioxidant to the phosphite antioxidant is (0.05-4):(0.05-2), for example, it can be 0.05:0.5, 0.05:1, 1:1, 2:1, 3:1 or 4:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] In this invention, by preferably using a combination of hindered phenolic antioxidants and phosphite antioxidants as anti-dripping agents and controlling the mass ratio of the two, the antioxidant and anti-yellowing effects can be enhanced through their synergistic effect, and the amount added is relatively small, thus reducing material costs.

[0038] Preferably, the pigment includes carbon black.

[0039] In this invention, carbon black is preferably used as the color powder, which has the advantages of strong dyeing ability, stable hue, high blackness, and good dispersibility.

[0040] Preferably, the laser engraving powder includes any one or a combination of at least two of antimony oxide, zinc antimony, aluminum antimony, or nickel antimony.

[0041] Secondly, the present invention provides a method for preparing a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material as described in the first aspect of the present invention, the preparation method comprising the following steps:

[0042] The raw materials are mixed according to the formula and then fed into a twin-screw extruder for sequential melting, compounding, extrusion, stringing, cooling and pelletizing to obtain the composite material.

[0043] Preferably, the processing temperature of the twin-screw extruder is 280-290℃, for example, it can be 280℃, 282℃, 284℃, 286℃, 288℃ or 290℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0044] Preferably, the screw speed of the twin-screw extruder is 400-600 rpm, for example, it can be 400 rpm, 420 rpm, 440 rpm, 460 rpm, 480 rpm, 500 rpm, 520 rpm, 540 rpm, 560 rpm, 580 rpm or 600 rpm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0045] Preferably, the composite material is subjected to injection molding and laser marking in sequence to obtain a white laser pattern.

[0046] Preferably, the raw materials are mixed according to the formula amount and then fed into a twin-screw extruder. Under the conditions of a processing temperature of 280-290℃ and a screw speed of 400-600rpm, the materials are melted, compounded, extruded, drawn into strands, cooled and pelletized in sequence to obtain the composite material.

[0047] The composite material was sequentially injection molded and laser-marked to obtain a white laser pattern.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The PC composite material provided by the present invention has high fluidity, can be used to manufacture ultra-thin parts, and reduces the difficulty of injection molding. In addition, it has good flame retardant properties without adding halogenated or fluorinated flame retardants, and meets the flame retardant requirements and fire rating at a thickness of (≥1.6mm). The PC composite material also has good notched impact strength, flexural strength and tensile strength, and excellent mechanical properties.

[0050] (2) The PC composite material provided by the present invention has a smooth surface after laser engraving, clear lettering, and is durable and not easy to fade, and has a good laser engraving effect. The laser engraving powder used in the present invention can not only provide laser engraving effect, but also has a dyeing effect, which can reduce the amount of color powder used and reduce material cost.

[0051] (3) The PC composite material provided by the present invention does not use halogenated additives or PFAS materials, and will not have a negative impact on human health and the environment, thus meeting the requirements of green environmental protection.

[0052] (4) The PC composite material provided by the present invention can be obtained by recycling plastic waste from daily production and life, such as drinking water bottles, CDs, and lamp shells, using PCR PC as raw material. This can reduce plastic pollution, reduce carbon dioxide emissions, and reduce energy consumption. Attached Figure Description

[0053] Figure 1 This is a laser effect photograph of the composite material provided in Embodiment 1 of the present invention;

[0054] Figure 2 This is a laser effect photograph of the composite material provided in Comparative Example 3 of the present invention. Detailed Implementation

[0055] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0056] Example 1

[0057] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The components of the raw materials used to prepare the PC composite material are shown in Table 1 by mass parts.

[0058] Among them, the polycarbonate is PCR PC, specifically bisphenol A type linear polycarbonate synthesized by phosgene method, with an MI of 59.2 g / 10 min (300℃ / 1.2 kg), a weight-average molecular weight Mw of 49,000-50,000, and a molecular weight distribution between 1.5 and 2.0.

[0059] This embodiment also provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material, the preparation method of which includes the following steps:

[0060] The raw materials are mixed according to the formula and then fed into a twin-screw extruder. Under the conditions of a processing temperature of 280℃ and a screw speed of 500rpm, the materials are melted, compounded, extruded, drawn, cooled and pelletized in sequence to obtain the composite material.

[0061] The composite material was injection molded into a product at 280℃, and then laser marking was performed using a Han's Laser EP-12 laser marking machine at a current of 20A, a marking speed of 1000mm / s, and a frequency of 17kHz to obtain a white laser pattern.

[0062] Table 1

[0063]

[0064]

[0065] Taking Example 1 as an example, the laser effect photograph of the composite material obtained in this example is as follows: Figure 1 As shown, from Figure 1 As can be seen, the surface is smooth and the lettering is clear after laser engraving, demonstrating excellent laser engraving results.

[0066] Example 2

[0067] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The components of the raw materials used to prepare the PC composite material are shown in Table 2 by mass.

[0068] This embodiment also provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material, the preparation method of which includes the following steps:

[0069] The raw materials are mixed according to the formula and then fed into a twin-screw extruder. Under the conditions of a processing temperature of 280℃ and a screw speed of 500rpm, the materials are melted, compounded, extruded, drawn, cooled and pelletized in sequence to obtain the composite material.

[0070] The composite material was injection molded into a product at 280℃, and then laser marking was performed using a Han's Laser EP-12 laser marking machine at a current of 20A, a marking speed of 1000mm / s, and a frequency of 17kHz to obtain a white laser pattern.

[0071] Table 2

[0072]

[0073]

[0074] Example 3

[0075] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The components of the raw materials used to prepare the PC composite material are shown in Table 3 by mass.

[0076] This embodiment also provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material, the preparation method of which includes the following steps:

[0077] The raw materials are mixed according to the formula and then fed into a twin-screw extruder. Under the conditions of a processing temperature of 280℃ and a screw speed of 500rpm, the materials are melted, compounded, extruded, drawn, cooled and pelletized in sequence to obtain the composite material.

[0078] The composite material was injection molded into a product at 280℃, and then laser marking was performed using a Han's Laser EP-12 laser marking machine at a current of 20A, a marking speed of 1000mm / s, and a frequency of 17kHz to obtain a white laser pattern.

[0079] Table 3

[0080]

[0081] Example 4

[0082] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that no phosphorus-based flame retardant is added, and the mass fractions of sulfonate-based flame retardant and organosilicon-based flame retardant are adjusted according to the original proportions to keep the mass fractions of flame retardant unchanged.

[0083] Example 5

[0084] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that no sulfonate flame retardant is added, and the mass fractions of phosphorus-based flame retardant and organosilicon-based flame retardant are adjusted according to the original proportions to keep the mass fractions of flame retardant unchanged.

[0085] Example 6

[0086] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that no organosilicon flame retardant is added, and the mass fractions of sulfonate flame retardant and phosphorus flame retardant are adjusted according to the original ratio so that the mass fractions of flame retardant remain unchanged.

[0087] Example 7

[0088] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that the total mass fraction of the flame retardant remains unchanged, and the mass ratio of phosphorus-based flame retardant, sulfonate-based flame retardant and organosilicon-based flame retardant in the flame retardant is 10:0.1:0.1.

[0089] Example 8

[0090] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that the total mass fraction of the flame retardant remains unchanged, and the mass ratio of phosphorus-based flame retardant, sulfonate-based flame retardant and organosilicon-based flame retardant in the flame retardant is 2:11:11.

[0091] Example 9

[0092] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that the total mass fraction of antioxidants remains unchanged, and the mass ratio of hindered phenolic antioxidants to phosphite antioxidants in the antioxidants is 0.01:1.

[0093] Example 10

[0094] This embodiment provides a halogen-free and fluorine-free high-flowability laser-engravable flame-retardant PC composite material. The only difference between the PC composite material and that in Example 1 is that the total mass fraction of antioxidants remains unchanged, and the mass ratio of hindered phenolic antioxidants to phosphite antioxidants in the antioxidants is 1:4.

[0095] Comparative Example 1

[0096] This comparative example provides a PC composite material, which differs from Example 1 only in that it does not contain a toughening agent.

[0097] Comparative Example 2

[0098] This comparative example provides a PC composite material, which differs from Example 1 only in that it does not contain color powder.

[0099] Comparative Example 3

[0100] This comparative example provides a PC composite material, which differs from Example 1 only in that it does not contain laser engraving powder.

[0101] Taking Comparative Example 3 as an example, the laser effect photograph of the composite material obtained in this comparative example is as follows: Figure 2 As shown, from Figure 2 As can be seen, the surface is rough after laser engraving, the lettering is blurry, and the color is uneven.

[0102] Performance testing:

[0103] The composite materials obtained in Examples 1-10 and Comparative Examples 1-3 were subjected to performance tests.

[0104] The melt flow index of the composite material at 260°C and 2.16 kg pressure was tested according to ISO 1133; the weight-average molecular weight of the composite material was tested according to GPC gel permeation chromatography; the notched impact strength of the composite material at 23°C was tested according to ISO 180; the flexural strength was tested according to ISO 178; the tensile strength was tested according to ISO 527; and the flame retardancy rating of the composite material was evaluated according to the UL 94 standard for flammability of plastic materials. The results are shown in Table 4.

[0105] Table 4

[0106]

[0107]

[0108] As can be seen from the data in Table 4:

[0109] (1) As can be seen from the comparison between Example 1 and Examples 4-6, the combination of phosphorus flame retardant, sulfonate flame retardant and organosilicon flame retardant in Example 1, compared with the absence of any one of the flame retardants in Examples 4-6, results in a flame retardant rating of V-0, which is significantly higher than that in Examples 4-6. Therefore, it can be seen that the present invention can further improve the flame retardant performance of PC composite materials by preferably using a combination of phosphorus flame retardant, sulfonate flame retardant and organosilicon flame retardant.

[0110] (2) As can be seen from the comparison between Example 1 and Example 7-8, in Example 1, by optimizing the mass ratio of phosphorus flame retardant, sulfonate flame retardant and organosilicon flame retardant, the flame retardant level in Example 1 is significantly higher than that in Example 7-8, where the mass ratio is not within the preferred range of the present invention. Therefore, it can be seen that the present invention can further improve the flame retardant effect by optimizing the mass ratio of flame retardants.

[0111] (3) As can be seen from the comparison between Example 1 and Examples 9-10, in Example 1, by optimizing the mass ratio of hindered phenolic antioxidants and phosphite antioxidants, the mechanical properties such as notched impact strength, bending strength and tensile strength are better than in Examples 9-10, where the mass ratio is not within the preferred range of the present invention. Therefore, it can be seen that the present invention can enhance the antioxidant effect and further improve the mechanical properties by optimizing the mass ratio of antioxidants.

[0112] (4) As can be seen from the data of Example 1 and Comparative Examples 1-3, the PC composite material provided by the present invention further improves the mechanical properties of the material such as notched impact strength, flexural strength and tensile strength by adding toughening agent. Although the color powder and laser engraving powder have little effect on flame retardancy and mechanical properties, the addition of color powder plays a role in adjusting the color of PC composite material, and the addition of laser engraving powder affects the laser effect of the material. It can be seen that the present invention can achieve good comprehensive performance through the synergistic effect of each component.

[0113] In summary, the PC composite material provided by this invention has good flame retardancy and flowability, excellent laser engraving effect, and avoids the use of halogen-containing additives and PFAS materials, making it environmentally friendly.

[0114] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A halogen-free, fluorine-free, high-flowability, laser-engravable flame-retardant PC composite material, characterized in that, The PC composite material, by mass fraction, comprises the following components in its preparation raw materials:

2. The high-flowability, laser-engravable flame-retardant PC composite material according to claim 1, characterized in that, The polycarbonate includes virgin polycarbonate and / or post-consumer recycled polycarbonate; Preferably, the polycarbonate includes any one or a combination of at least two of the following: bisphenol A type polycarbonate, polyester type polycarbonate, organosilicon copolymer polycarbonate, cyclohexane bisphenol A type polycarbonate, and polycarbonate synthesized from bisphenol TMC. Preferably, the polycarbonate has a melt mass flow rate of 4-70 g / 10 min at 300°C and 1.2 kg pressure; Preferably, the polycarbonate has a weight-average molecular weight of 20,000-50,000; Preferably, the polycarbonate has a molecular weight distribution of 1-2.

5.

3. The high-flowability, laser-engravable flame-retardant PC composite material according to claim 1 or 2, characterized in that, The toughening agent includes any one or a combination of at least two of the following: core-shell acrylate-PMMA toughening agents, core-shell acrylate-SAN toughening agents, core-shell silicone-PMMA toughening agents, core-shell silicone-SAN toughening agents, cross-linked methacrylate-methyl methacrylate toughening agents, butadiene-styrene-methyl methacrylate toughening agents, or silicone rubber-methyl methacrylate toughening agents.

4. The high-flowability, laser-engravable flame-retardant PC composite material according to any one of claims 1-3, characterized in that, The flame retardant includes a combination of phosphorus-based flame retardants, sulfonate-based flame retardants, and organosilicon-based flame retardants; Preferably, the phosphorus-based flame retardant includes hypophosphite-based flame retardants and / or phosphate ester-based flame retardants; Preferably, the hypophosphite-based flame retardant comprises vinyl aluminum hypophosphite and / or vinyl hypophosphite; Preferably, the phosphate ester flame retardant includes any one or a combination of at least two of the following: 1,3-phenylene phosphate (2,6-tolyl) tetraester flame retardant, tetraphenylbisphenol A diphosphate and its derivatives flame retardant, tetraphenylresorcinol diphosphate and its derivatives flame retardant, or triphenyl phosphate flame retardant. Preferably, the sulfonate flame retardant includes any one or a combination of at least two of potassium benzenesulfonylbenzenesulfonate, potassium perfluorobutylsulfonate, or sodium 2,4,5-trichlorobenzenesulfonate; Preferably, the organosilicon flame retardant includes any one or a combination of at least two of the following: polysiloxane and its derivative flame retardants, cross-linked polydimethylsiloxane and its derivative flame retardants, or methyl / phenyl organosilicon flame retardants. Preferably, the mass ratio of phosphorus-based flame retardant, sulfonate-based flame retardant and organosilicon-based flame retardant in the flame retardant is (1-10):(0.2-10):(0.2-10).

5. The high-flowability, laser-engravable flame-retardant PC composite material according to any one of claims 1-4, characterized in that, The anti-dripping agent includes fluorine-free nano-clay materials.

6. The high-flowability, laser-engravable flame-retardant PC composite material according to any one of claims 1-5, characterized in that, The antioxidants include any one or a combination of at least two of hindered phenolic antioxidants, hindered amine antioxidants, or phosphite antioxidants. Preferably, the hindered phenolic antioxidant includes (β-3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl acrylate; Preferably, the hindered amine antioxidant includes diphenylamine and its derivatives antioxidants and / or p-phenylenediamine antioxidants; Preferably, the phosphite antioxidant includes tris(2,4-di-tert-butylphenyl) phosphite and / or pentaerythritol diphosphite; Preferably, the antioxidant comprises a combination of hindered phenolic antioxidants and phosphite antioxidants; Preferably, the mass ratio of the hindered phenolic antioxidant to the phosphite antioxidant is (0.05-4):(0.05-2).

7. The high-flowability, laser-engravable flame-retardant PC composite material according to any one of claims 1-6, characterized in that, The pigment includes carbon black; Preferably, the laser engraving powder includes any one or a combination of at least two of antimony oxide, zinc antimony, aluminum antimony, or nickel antimony.

8. A method for preparing a halogen-free, fluorine-free, highly fluid, laser-engravable flame-retardant PC composite material as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: The raw materials are mixed according to the formula and then fed into a twin-screw extruder for sequential melting, compounding, extrusion, stringing, cooling and pelletizing to obtain the composite material.

9. The preparation method according to claim 8, characterized in that, The processing temperature of the twin-screw extruder is 280-290℃; Preferably, the screw speed of the twin-screw extruder is 400-600 rpm; Preferably, the composite material is subjected to injection molding and laser marking in sequence to obtain a white laser pattern.

10. The preparation method according to claim 8 or 9, characterized in that, The preparation method includes the following steps: The raw materials are mixed according to the formula and then fed into a twin-screw extruder. Under the conditions of a processing temperature of 280-290℃ and a screw speed of 400-600rpm, the materials are melted, compounded, extruded, drawn, cooled and pelletized in sequence to obtain the composite material. The composite material was sequentially injection molded and laser-marked to obtain a white laser pattern.

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