Laser direct structuring polycarbonate blend composition, preparation and application

Abstract

The invention discloses a laser direct structuring polycarbonate blend composition as well as preparation and application thereof, and the laser direct structuring polycarbonate blend composition mainly comprises the following components in percentage by weight: 40-70% of a polycarbonate blend and 0.5-5% of an organic silicon modifier, 5 to 20% of a polycarbonate-polysiloxane copolymer; 1 to 5% of polyketone; 1-10% of a flame retardant; 2-10% of an additive that can be activated by laser; 5-40% of an inorganic filler; and 0.5-5% of other additives. According to the invention, the problem that the laser direct structuring polycarbonate blend can simultaneously reach UL94 V0 vertical combustion and needle flame test S2 grade under the thin-wall condition is solved, and meanwhile, the material has excellent mechanical properties and good chemical plating effect.

Description

Technical Field

[0001] This invention belongs to the field of laser direct structuring technology, specifically relating to a laser direct structuring polycarbonate blend composition, its preparation and application. Background Technology

[0002] Laser Direct Structuring (LDS) is a technology that uses laser technology to directly 3D print circuit boards onto special plastic parts. This technology combines the flexibility and precision of lasers with the plasticity and functionality of engineering plastics, greatly simplifying the production process, providing flexible design space, and offering high processing resolution (laser beam diameter < 80 µm). In the research and development of LDS engineering plastics, modified materials based on polycarbonate have been widely used in communications, automotive electronics, electromechanical equipment, and medical devices.

[0003] For safety testing of electronic and electrical products, the S2 needle flame test is a standard in fire resistance and flame retardancy testing, primarily used to evaluate the flame retardant performance of materials or products under contact with a needle-like flame source. This test is applicable to electronic and electrical equipment, new energy vehicle components, industrial equipment and their materials, such as insulating plastics and flame-retardant composite materials, simulating persistent or recurring fault flames that may occur in real-world environments. By extending the burning time, the S2 needle flame test more realistically assesses the fire resistance reliability of materials in actual use, further improving the product's safety level.

[0004] Currently, according to the latest national standards, for the field of laser-directly structured polycarbonate blend compositions, it is necessary to provide technical solutions that can meet UL94 V0 and needle flame test S2 levels, while the materials must also have excellent mechanical properties and coating performance. Summary of the Invention

[0005] This invention provides a laser-directly structured polycarbonate blend composition that solves the problem of simultaneously meeting the UL94 V0 vertical burning and needle flame test S2 level requirements under thin-walled product design conditions.

[0006] The present invention also provides a method for preparing the above-mentioned polycarbonate blend composition.

[0007] The present invention also provides an article prepared from the above-mentioned polycarbonate blend composition.

[0008] The present invention adopts the following technical solution:

[0009] A laser-directly structured polycarbonate blend composition, by weight percentage, mainly comprises: 40-70% polycarbonate; 0.5-5% silicone modifier; 5-20% polycarbonate-polysiloxane copolymer; 1-5% polyketone; 1-10% flame retardant; 2-10% laser-activated additives; 5-40% inorganic filler; and 0.5-5% other additives.

[0010] Preferably, the organosilicon modifier has a weight percentage of 1-5%; more preferably 2-5%; and even more preferably 3-5%.

[0011] Preferably, the polyketone has a weight percentage of 1-4%; more preferably 2-4%.

[0012] In this invention, the polycarbonate comprises homopolymer and copolymer of polycarbonate having repeating carbonate units, and may be one or a mixture of two of aliphatic polycarbonate, alicyclic polycarbonate, or aromatic polycarbonate. In this invention, suitable polycarbonate can be prepared by methods such as interfacial polymerization and melt polymerization. In a particular embodiment, the polycarbonate is a linear homopolymer derived from bisphenol A, i.e., an aromatic polycarbonate containing a bisphenol A structure, as shown in the following formula:

[0013]

[0014] The polycarbonate used in this invention can be any commercially available polycarbonate product, such as bisphenol A polycarbonate purchased from Bayer AG in Germany, Teijin in Japan, or some domestic companies.

[0015] Furthermore, the melt index of the polycarbonate was determined to be 4-25 g / 10min at 300°C and 1.2 kg.

[0016] In this invention, the organosilicon modifier is one or a mixture of two of phenyl silicone resin and ultra-high molecular weight siloxane, and can be a polymer or oligomer. Further, the phenyl silicone resin contains hydroxyl functional groups. Preferably, the phenyl silicone resin is a siloxane polymer containing one or more benzene ring structures and one or more hydroxyl functional groups.

[0017] Preferably, the structure of the phenyl silicone resin is as follows:

[0018]

[0019] In this formula, each of the two R1 groups is independently selected from hydroxyl, hydroxyalkyl vinyl, or hydroxyalkyl groups, wherein the alkyl group is a straight-chain or branched alkylene group containing 1 to 5 carbon atoms. The plurality of R2 and R3 groups are independently selected from alkyl, vinyl, capped or uncapped polysiloxane groups, etc., wherein the alkyl group is a straight-chain or branched alkyl group containing 1 to 5 carbon atoms; preferably, the plurality of R2 and R3 groups are independently methyl, ethyl, or hydroxyl-capped polysiloxane groups; the plurality of R4 and R5 groups are independently selected from unsubstituted or substituted phenyl groups, preferably, R4 and R5 groups are independently selected from phenyl or tolyl (including ortho, meta, and para substitutions). The multiple substituents represented by the same symbol in the above formula can have the same substituent structure or different substituent structures. Wherein, x is an integer from 1 to 10000; y is an integer from 1 to 1000, and x:y exists in a ratio of 1:1 to 200:1.

[0020] In this invention, the ultra-high molecular weight siloxane can be directly synthesized by ordinary synthesis methods, or it can be compounded with inorganic powders. Preferably, the carrier of the ultra-high molecular weight siloxane in this invention is fumed silica. Preferably, the silicone content in the ultra-high molecular weight siloxane is 60-80%, more preferably 65-75%.

[0021] In this invention, the polycarbonate-polysiloxane copolymer may comprise 50-99 weight percent of carbonate units and 1-50 weight percent of siloxane units. As one embodiment, the polycarbonate-polysiloxane copolymer comprises 65-99 weight percent of carbonate units and 1-35 weight percent of siloxane units. More specifically, it comprises 70-98 weight percent of carbonate units and 2-30 weight percent of siloxane units; even further, it comprises 10-30 weight percent of siloxane units.

[0022] Preferably, the polycarbonate unit in the polycarbonate-polysiloxane copolymer is a polycarbonate unit structure with a bisphenol A structure.

[0023] The polycarbonate-polysiloxane copolymer has a weight-average molecular weight of 20,000-40,000.

[0024] In this invention, the polyketone is a copolymer of olefins and carbon monoxide arranged isotactically. Preferably, the polyketone has a melt index of 240. o C. The test result at 2.16 kg was 6-100 g / 10 min.

[0025] In this invention, the flame retardant comprises a phosphorus-containing flame retardant and / or a nitrogen-containing flame retardant. Further, the flame retardant comprises phosphine, hypophosphite, phosphite, phosphine oxide, hypophosphite, phosphate, phosphazene, melamine polyphosphate, melamine cyanurate, or combinations thereof. The phosphazene used in the flame retardant is an organic compound having a –P=N– bond in its molecule, including cyclic phosphazenes and chain phosphazenes. Preferably, the phosphazene compound is a cyclotriphosphazene, such as one or more of hexapropoxycyclotriphosphazene, hexaphenoxycyclotriphosphazene, hexamethylphenoxycyclotriphosphazene, hexaaminocyclotriphosphazene, and hexafluoroalkylcyclotriphosphazene. Preferably, the flame retardant comprises an oligomeric organophosphorus flame retardant, phenoxyphosphazene oligomer, or a combination thereof. As a specific preferred embodiment, the flame retardant is bisphenol A bis(diphenyl phosphate) or hexaphenoxycyclotriphosphazene or a mixture of both.

[0026] In this invention, the laser-directly structuring additive (i.e., laser-activated additive) is a metal compound and / or metal complex having a spinel or octahedral crystal structure. The metal compound may be one or a mixture of at least two of the following: zinc oxide, zinc organometallic compound, copper oxide, copper organometallic compound, cobalt oxide, cobalt organometallic compound, magnesium oxide, magnesium organometallic compound, tin oxide, tin organometallic compound, titanium oxide, titanium organometallic compound, iron oxide, iron organometallic compound, aluminum oxide, aluminum organometallic compound, nickel oxide, nickel organometallic compound, manganese oxide, manganese organometallic compound, chromium oxide, or chromium organometallic compound; preferably, one or a mixture of at least two of the following: copper oxide, copper organometallic compound, tin oxide, and tin organometallic compound. The metal complex may be one or a mixture of at least two of the following: zinc complex, copper complex, cobalt complex, magnesium complex, tin complex, titanium complex, iron complex, aluminum complex, nickel complex, manganese complex, or chromium complex; preferably, one or a mixture of at least two of the following: copper complex and tin complex. Examples of laser direct forming additives include, but are not limited to, metal oxides, metal oxide-coated fillers, and heavy metal mixture oxide spinels, such as copper chromium oxide spinel; copper salts, such as basic copper phosphate, copper phosphate, copper sulfate, and cuprous thiocyanate; organometallic compounds, such as palladium / palladium-containing heavy metal compounds or copper compounds; or combinations comprising at least one of the aforementioned LDS additives. As a specific alternative, the laser-activated additive is one or a mixture of two of basic copper phosphate and zinc stannate.

[0027] In this invention, the polycarbonate blend composition further comprises fillers, such as inorganic mineral powder and glass fiber, or a mixture of one or two inorganic fillers. Preferably, the inorganic filler comprises: inorganic mineral powder: 1-10%; glass fiber: 5-30%. Preferably, the inorganic mineral powder comprises one or more of talc, mica, kaolin, and wollastonite.

[0028] In addition to the components described above, the polycarbonate blend compositions disclosed in this invention may optionally contain one or more additive materials, including, for example, heat stabilizers (such as antioxidant 1010 and / or antioxidant 168), hydrolytic stabilizers, anti-dripping agents, chain extenders or light stabilizers, UV absorbing additives, plasticizers, lubricants, mold release agents, antistatic agents, colorants (such as pigments or dyes), or any combination thereof, which may be added as needed.

[0029] A method for preparing the aforementioned laser-directly structured polycarbonate blend composition includes: premixing the components and then co-extruding them using a twin-screw extruder. The premixing conditions and the extrusion conditions of the twin-screw extruder can be achieved using existing technologies. Preferably, the screw temperature in the twin-screw extruder is controlled between 240-270°C. The extruded granules are then dried by forced-air drying at 90-120°C for 3-8 hours before injection molding. The premixing can be completed in a high-speed mixer, and the premixing time is generally 3-5 minutes.

[0030] An article manufactured from the above-described laser-directly structured polycarbonate blend composition. The article is selected from applications related to consumer electronics, medical devices, automobiles, industrial equipment, or RFID. The laser-directly structured polycarbonate blend composition of the present invention can be used to manufacture various forms of molded articles using existing techniques in this field.

[0031] This invention enables flame-retardant polycarbonate blends to achieve UL94 V0 vertical burning and needle flame test S2 ratings under thin-wall conditions through innovative modification methods. At the same time, the material has excellent molding and processing performance and mechanical properties, and good laser engraving and chemical plating effects, which can fully meet the technical requirements of laser direct structuring. Detailed Implementation

[0032] To illustrate the invention in more detail, specific embodiments are described below.

[0033] The polycarbonates used in the comparative examples and the examples are all aromatic polycarbonates containing bisphenol A structures. Specifically, commercially available bisphenol A products from Teijin Corporation of Japan can be used. The MFRs at 300°C and 1.2 kg are 18 g / 10 min (PC-1) and 8 g / 10 min (PC-2), respectively.

[0034] The hydroxyl-containing phenyl silicone resin (Si-1) used in the examples is Wacker SILRES® 603.

[0035] The ultra-high molecular weight siloxane (Si-2) used in the examples is Wacker GENIOPLAST® Pellet S.

[0036] The polycarbonate-polysiloxane copolymer (PC-ST) used in the examples is Gansu Yinguang SL0301.

[0037] The polyketone POK used in the examples was Hyosung M330 from South Korea, with an MFR of 60 g / 10 min at 240°C and 2.16 kg.

[0038] The flame retardants used in the comparative examples and embodiments include bisphenol A bis(diphenyl phosphate) (FR-1) and hexaphenoxycyclotriphosphazene (FR-2).

[0039] The laser-activated additives used in the comparative examples and embodiments include basic copper phosphate (LDS-1) and zinc stannate (LDS-2).

[0040] The wollastonite (WOLL) used in the comparative examples and embodiments was WFC5-21-1 from Hubei Fengjiashan Silicon Fiber Co., Ltd.

[0041] The glass fiber (GF) used in the comparative examples and embodiments was Jushi ECS13-03-510.

[0042] Other additives include commonly used heat stabilizers, and are added in the usual amounts.

[0043] Weigh out the following components according to the specified proportions: PC, silicone modifier, polycarbonate-polysiloxane copolymer, polyketone, flame retardant, laser-activated additive, wollastonite, glass fiber, and heat stabilizer. Add all raw materials except glass fiber to a high-speed mixer and premix at high speed for 5 minutes. The premixed raw material mixture is then fed into a twin-screw extruder via the main feeder, while the glass fiber is added via the side feeder. The mixture undergoes melting, mixing, extrusion, cooling, drying, and pelletizing, with the screw temperature of the twin-screw extruder controlled between 240-255℃. The extruded pellets are then dried in a forced-air environment at 110℃ for 4 hours before injection molding, followed by various mechanical property tests and chemical plating evaluations.

[0044] The following standards were adopted for all mechanical property tests:

[0045] Tensile property testing: ASTM D 638;

[0046] Bending performance test: ASTM D 790;

[0047] Impact performance testing: ASTM D256 / ASTM D4812;

[0048] Flame retardancy testing: UL94 V0 standard; GB4943.1-2022 needle flame test

[0049] Table 1

[0050]

[0051] As shown in Table 1, the test results in Comparative Examples 1 and 2, using flame retardants and adding a certain amount of polyketone, indicate that the flame retardant test (1.5 mm thickness) shows that the samples exhibit prolonged burning under vertical burning conditions, only meeting the V1 standard; in the needle flame test, the samples also fail to meet the requirement of no burn-through within 60 seconds of burning. However, in Example 1, with the addition of a silicone modifier, the needle flame test results of the sample show significant improvement, meeting the S2 requirement. Furthermore, in Example 2, with a further increase in POK dosage, both UL94 V0 and needle flame tests can be passed simultaneously, but this significantly affects the toughness of the composite system. Therefore, in Examples 3-5, the polyketone dosage is kept at a low level, while the dosage of both silicone modifiers is further increased. It can be seen that when both vertical burning and needle flame tests are passed simultaneously, the strength and toughness of the polycarbonate blend composition remain at a high level. In Examples 6-7, the amounts of wollastonite and glass fiber were further increased, significantly improving the strength and modulus of the composite while maintaining excellent combustion performance and only slightly decreasing impact strength. It should be noted that the plating properties of all polycarbonate blend compositions remained at an excellent level.

[0052] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. A laser-directly structured polycarbonate blend composition, characterized in that, By weight percentage, it mainly includes: polycarbonate 40-70%; organosilicon modifier: 0.5-5%; polycarbonate-polysiloxane copolymer 5-20%; polyketone 1-5%; flame retardant 1-10%; laser-activated additives 2-10%; inorganic filler 5-40%; other additives: 0.5-5%.

2. The laser-directly structured polycarbonate blend composition according to claim 1, characterized in that, The organosilicon modifier is one or a mixture of two of phenyl silicone resin and ultra-high molecular weight siloxane.

3. The laser-directly structured polycarbonate blend composition according to claim 2, characterized in that, The phenyl silicone resin is a phenylsiloxane polymer containing one or more hydroxyl functional groups.

4. The laser-directly structured polycarbonate blend composition according to claim 1, characterized in that, The melt index of the polycarbonate was determined to be 4-25 g / 10min at 300°C and 1.2 kg; the polycarbonate-polysiloxane copolymer contained 1-30% by weight of siloxane units; the melt index of the polyketide was determined to be 6-100 g / 10min at 240°C and 2.16 kg.

5. The laser-directly structured polycarbonate blend composition according to claim 1, characterized in that, The flame retardant comprises oligomeric organophosphorus flame retardants, phenoxyphosphazene oligomers, or combinations thereof.

6. The laser-directly structured polycarbonate blend composition according to claim 1, characterized in that, The laser direct structuring additives are selected from metal compounds and / or metal complexes having spinel or octahedral crystal structures.

7. The laser-directly structured polycarbonate blend composition according to claim 1, characterized in that, The inorganic filler includes one or more of inorganic mineral powder and glass fiber; the inorganic mineral powder includes one or more of talc, mica, kaolin, and wollastonite.

8. The laser-directly structured polycarbonate blend composition according to claim 7, characterized in that, The inorganic mineral powder has a weight percentage of 1-10%; the glass fiber has a weight percentage of 5-30%.

9. A method for preparing a laser-directly structured polycarbonate blend composition according to any one of claims 1-8, characterized in that, include: The components are premixed and then co-extruded in a twin-screw extruder to obtain the final product.

10. An article made from the laser-directly structured polycarbonate blend composition according to any one of claims 1-8.

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