Flame-retardant aromatic polycarbonate resin composition and molded article made therefrom

Abstract

The present invention provides a flame-retardant aromatic polycarbonate resin composition and molded articles made therefrom that exhibit high flame retardancy without the presence of flame retardants, as well as good heat resistance and transparency. [Solution] A flame-retardant aromatic polycarbonate resin composition comprising an aromatic polycarbonate resin (PC-A) obtained with the following formula (1) as the divalent phenol component and an aromatic polycarbonate resin (PC-M) obtained with the following formula (2) as the divalent phenol component, characterized in that the mass ratio (%) of PC-A to PC-M is 0 to 20:100 to 80. [Formula 1] JPEG2026136459000008.jpg1863 [C2] JPEG2026136459000009.jpg2068

Description

[Technical Field]

[0001] This invention relates to a flame-retardant aromatic polycarbonate resin and molded articles made therefrom. [Background technology]

[0002] Aromatic polycarbonate resins are widely used in various industrial fields as materials for molded products through simple and highly productive processing methods such as injection molding. In particular, aromatic polycarbonate resins are widely used in applications requiring high transparency, such as various lighting covers and protective covers for transparent displays, taking advantage of their excellent transparency, exemplified by their high light transmittance and extremely low haze. Furthermore, their flame retardancy in the event of a fire is also attracting attention in these applications. In addition, as molded products become thinner, smaller, and lighter, there is a demand for further performance improvements in molding materials, and among these, the development of polycarbonate resins with high flame retardancy even at thin walls has become desirable, and several proposals have been made.

[0003] For example, Patent Document 1 describes a polycarbonate resin composition having good flame retardancy and impact resistance, obtained by adding another polycarbonate resin and a flame retardant to a polycarbonate resin made from a specific monomer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent No. 6,174,942 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, conventionally known technologies have not been able to obtain a flame-retardant aromatic polycarbonate resin composition that achieves flame retardancy level V-0 in vertical combustion tests based on UL standard 94, while also exhibiting good heat resistance and transparency, without the presence of flame retardants.

[0006] The object of the present invention is to provide a flame-retardant aromatic polycarbonate resin composition and a molded article made therefrom that has high flame retardancy without the presence of a flame retardant, as well as good heat resistance and transparency. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to achieve this objective and, as a result, discovered that a polycarbonate resin composition containing a polycarbonate resin of a specific structure in a specific range of proportions can solve the aforementioned problem, leading to the present invention. That is, the present invention is as follows.

[0008] (1) A flame-retardant aromatic polycarbonate resin composition comprising an aromatic polycarbonate resin (PC-A) obtained with the following formula (1) as the divalent phenol component and an aromatic polycarbonate resin (PC-M) obtained with the following formula (2) as the divalent phenol component, wherein the mass ratio (%) of PC-A to PC-M is 0 to 20:100 to 80. [ka] [ka]

[0009] (2) The flame-retardant aromatic polycarbonate resin composition according to item (1) above, wherein the viscosity-average molecular weight of the aromatic polycarbonate resin (PC-A) is in the range of 10,000 to 40,000. (3) The flame-retardant aromatic polycarbonate resin composition according to item (1) or (2) above, wherein the viscosity-average molecular weight of the aromatic polycarbonate resin (PC-M) is in the range of 10,000 to 40,000. (4) A flame-retardant aromatic polycarbonate resin composition as described in any of the preceding paragraphs (1) to (3), used for 3D printing. (5) The flame-retardant aromatic polycarbonate resin composition described in item (4) above, used for 3D printers, which are filament-shaped with a diameter of 0.2 to 5.0 mm. (6) A molded article formed from the flame-retardant aromatic polycarbonate resin composition according to any one of (1) to (3) above. (7) The molded article according to (6) above, wherein the molded article is a 3D printer molded article. (8) The molded article according to (7) above, wherein the molded article is a 3D printer molded article formed by the fused deposition method. (9) A flame-retardant insulating sheet or film formed from the flame-retardant aromatic polycarbonate resin composition according to any one of (1) to (3) above. (10) An electric or electronic device using the flame-retardant insulating sheet or film according to (9) above.

Advantages of the Invention

[0010] The flame-retardant aromatic polycarbonate resin composition of the present invention has flame retardancy without containing a flame retardant by limiting the polycarbonate resin having a specific structure to a specific range, and these technologies are not available in conventional flame retardant technologies. And the flame-retardant aromatic polycarbonate resin composition of the present invention can also impart high flame retardancy without using fluorine compounds whose regulations are considered to be strengthened in the future, and is extremely useful for various industrial applications such as the OA equipment field and the electric and electronic equipment field, and the industrial effect it exhibits is extremely large.

Modes for Carrying Out the Invention

[0011] The present invention will be described in more detail.

[0012] <Flame-Retardant Aromatic Polycarbonate Resin Composition> In the flame-retardant aromatic polycarbonate resin composition of the present invention, the mass ratio of the aromatic polycarbonate resin (PC-A) obtained using the following formula (1) as the divalent phenol component is 0 to 20%. Preferably it is 5 to 20%, more preferably 10 to 20%. If it is higher than the above upper limit, satisfactory flame retardancy cannot be obtained. Also, by adjusting the mass ratio of PC-A, it is possible to adjust the glass transition temperature.

[0013]

Chemical Formula

[0014] In the flame-retardant aromatic polycarbonate resin composition of the present invention, the mass ratio of the aromatic polycarbonate resin (PC-M) obtained using the following formula (2) as the divalent phenol component is 100 to 80%. Preferably it is 95 to 80%, more preferably 90 to 80%. If it is lower than the above lower limit, satisfactory flame retardancy cannot be obtained.

[0015]

Chemical formula

[0016] The viscosity average molecular weight of PC-A contained in the flame-retardant aromatic polycarbonate resin composition of the present invention preferably ranges from 10,000 to 40,000, more preferably from 12,000 to 35,000, and even more preferably from 15,000 to 30,000. If the molecular weight exceeds the above upper limit, the melt tension may be high and the moldability may be poor. If the molecular weight is less than the above lower limit, in addition to the melt tension becoming low, extrusion molding and blow molding may become difficult, and the mechanical properties may decrease.

[0017] Also, the viscosity average molecular weight of PC-M contained in the flame-retardant aromatic polycarbonate resin composition of the present invention preferably ranges from 10,000 to 40,000, more preferably from 12,000 to 35,000, and even more preferably from 15,000 to 30,000. If the molecular weight exceeds the above upper limit, the melt tension may be high and the moldability may be poor. If the molecular weight is less than the above lower limit, in addition to the melt tension becoming low, extrusion molding and blow molding may become difficult, and the mechanical properties may decrease.

[0018] Also, in the flame-retardant aromatic polycarbonate resin composition of the present invention, the total light transmittance of a molded plate with a thickness of 2.0 mm is preferably 85%, more preferably 86% or more, and even more preferably 87% or more. The upper limit is not particularly limited, but 92% or less is sufficient.

[0019] In this invention, the viscosity-average molecular weight is first determined by calculating the specific viscosity using the following formula, from a solution prepared by dissolving 0.7 g of polycarbonate resin in 100 mL of methylene chloride at 20°C, using an Ostwald viscometer. Specific viscosity (η SP ) = (t-t0) / t0 [t0 is the number of seconds for the methylene chloride to fall, and t is the number of seconds for the sample solution to fall.] The viscosity-average molecular weight Mv is calculated by substituting the obtained specific viscosity into the following equation. η SP / c=[η]+0.45×[η] 2 c (where [η] is the intrinsic viscosity) [η] = 1.23 × 10 -4 M 0.83 c = 0.7

[0020] Regarding the molecular weights of PC-A and PC-M contained in the flame-retardant aromatic polycarbonate resin composition of the present invention, it is desirable that they be similar in terms of compatibility. If the molecular weights are similar, the mobility and interactions of the polymer chains will be similar, which is thought to facilitate uniform mixing.

[0021] The polycarbonate resin contained in the flame-retardant aromatic polycarbonate resin composition of the present invention is obtained by reacting a dihydroxy compound with a carbonate precursor. Reaction methods include interfacial polycondensation, molten transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds. In the case of interfacial polycondensation, monovalent phenols are usually used as end-terminating agents.

[0022] In reactions using phosgene as a carbonate precursor, the reaction is usually carried out in the presence of an acid binder and a solvent. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, or amine compounds such as pyridine. Examples of solvents include halogenated hydrocarbons such as methylene chloride and chlorobenzene. Catalysts such as tertiary amines or quaternary ammonium salts can also be used to accelerate the reaction. The reaction temperature is typically 0-40°C, and the reaction time is several minutes to 5 hours.

[0023] Transesterification reactions using, for example, diester carbonate as a carbonate precursor are carried out by heating and stirring a predetermined proportion of aromatic dihydroxy components with the diester carbonate under an inert gas atmosphere, and distilling off the resulting alcohol or phenol. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is usually in the range of 120 to 300°C. The reaction is completed by reducing the pressure from the beginning and distilling off the resulting alcohol or phenol. A catalyst commonly used in transesterification reactions can also be used to accelerate the reaction. Examples of diester carbonates used in the transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Of these, diphenyl carbonate is particularly preferred.

[0024] Monofunctional phenols, commonly used as end-terminating agents, can be used. In particular, in reactions using phosgene as a carbonate precursor, monofunctional phenols are generally used as end-terminating agents to adjust molecular weight, and the resulting polycarbonate resin has superior thermal stability compared to those that are not, because its ends are sealed by groups based on monofunctional phenols. Specific examples of the monofunctional phenols include, for example, phenol, m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, 1-phenylphenol, 2-phenylphenol, p-tert-butylphenol, p-cumylphenol, isooctylphenol, and p-long-chain alkylphenols.

[0025] <Other ingredients> The flame-retardant aromatic polycarbonate resin composition of the present invention may be blended with other resins to impart various functions or improve the properties of the molded article; however, the type and amount of other resins should be carefully considered so as not to impair the objectives of the present invention.

[0026] The flame-retardant aromatic polycarbonate resin composition of the present invention may contain additives such as heat stabilizers, plasticizers, light stabilizers, polymerization metal deactivators, flame retardants, lubricants, antistatic agents, surfactants, antibacterial agents, antioxidants, ultraviolet absorbers, and mold release agents, as needed, to impart various functions to molded articles and improve their properties.

[0027] <Regarding the manufacture of flame-retardant aromatic polycarbonate resin compositions> Any method can be used to produce the flame-retardant aromatic polycarbonate resin composition of the present invention. For example, PC-A, PC-M, and other components as needed can be thoroughly mixed using pre-mixing means such as a V-type blender, Henschel mixer, mechanochemical device, or extruder, and then granulated using an extruder or briquetting machine as needed, followed by melt-kneading in a melt-kneader such as a vented twin-screw extruder, and then pelletized using equipment such as a pelletizer. Alternatively, PC-A, PC-M, and other components as needed can be supplied independently to a melt-kneader such as a vented twin-screw extruder, PC-A, PC-M, and some of the other components can be pre-mixed and then supplied to the melt-kneader with the remaining components, and other components can be diluted and mixed with water or an organic solvent as needed before being supplied to the melt-kneader, or such diluted mixture can be pre-mixed with other components before being supplied to the melt-kneader. Furthermore, if any of the ingredients to be blended are in liquid form, a so-called liquid injection device or liquid additive device can be used to supply them to the melting and mixing machine.

[0028] Furthermore, it is preferable that PC-A and PC-M have the same shape in order to mix them uniformly. For example, if one is in pellet form and the other is in powder form, it is preferable to crush the pellet form or melt-extrude the powder form to create the pellet form.

[0029] <Filament-shaped flame-retardant aromatic polycarbonate resin composition> The flame-retardant aromatic polycarbonate resin composition of the present invention is preferably in the form of a filament when used as a material for 3D printed articles, as described later. By being in the form of a filament, it can be suitably used as a molding material for fused deposition modeling (FDM) 3D printers. The filament can be monofilament or multifilament, but monofilament is preferred. Furthermore, the filament may or may not be stretched.

[0030] The filament shape is preferably such that the diameter is 0.2 to 5.0 mm, more preferably 1.5 to 3.2 mm, and even more preferably 1.6 to 3.1 mm. If the diameter of the filament is below the lower limit, it may become too thin and unsuitable for general-purpose fused deposition modeling (FDM) 3D printers. The upper limit of the diameter of a filament-like molded body suitable for general-purpose FDM 3D printers is approximately the upper limit mentioned above (for example, 5.0 mm).

[0031] <Manufacturing of molded products> The flame-retardant aromatic polycarbonate resin composition of the present invention can be used to manufacture various products by obtaining molded articles through injection molding or 3D printing. In injection molding, it is possible to manufacture not only using the conventional cold runner method but also using a hot runner that enables runnerless production. Furthermore, in injection molding, in addition to conventional molding methods, gas-assisted injection molding, injection compression molding, ultra-high-speed injection molding, injection press molding, two-color molding, sandwich molding, in-mold coating molding, insert molding, foam molding (including those using supercritical fluids), rapid heating and cooling mold molding, in-mold remelting molding, and molding methods consisting of combinations thereof can be used. In 3D printing, fused deposition modeling and the like can be used. Furthermore, the flame-retardant aromatic polycarbonate resin composition of the present invention can also be molded into a product by rotational molding without melt mixing.

[0032] Furthermore, molded articles formed from flame-retardant aromatic polycarbonate resin compositions can undergo various surface treatments. These surface treatments include decorative coating, hard coating, water-repellent / oil-repellent coating, hydrophilic coating, UV-absorbing coating, infrared-absorbing coating, electromagnetic wave-absorbing coating, heat-generating coating, antistatic coating, antistatic coating, conductive coating, and metallizing (plating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thermal spraying, etc.). Articles coated with a transparent conductive layer on a transparent sheet are particularly preferred.

[0033] <Flame-retardant insulating sheet or film> It is preferable to manufacture a flame-retardant insulating sheet or film using the flame-retardant aromatic polycarbonate resin composition of the present invention. The method for manufacturing the flame-retardant insulating sheet or film is not particularly limited, but methods such as calendering, extrusion, pressing, and casting can be used.

[0034] There are no specific requirements regarding the thickness of the flame-retardant insulating sheet or film, but it is preferably 10 μm to 500 μm, and more preferably 25 μm to 250 μm.

[0035] The resulting flame-retardant insulating sheet or film can be suitably used in electrical and electronic equipment where flame retardancy is required. [Examples]

[0036] The present invention will be further described in detail by the following examples, but the present invention is not limited thereto. The evaluation was performed according to the following method.

[0037] Evaluation Method (i) Glass transition temperature (Tg) The obtained resin composition was measured using a TA Instruments Discovery SDT650 differential thermal and thermogravimetric analyzer under a nitrogen atmosphere at a heating rate of 20°C / min. Approximately 5 mg of sample was used for the measurement. (ii) Transparency of the molded sheet A 2.0 mm thick molded plate of the obtained resin composition was formed, and the total light transmittance was measured using a color and turbidity simultaneous measuring instrument (COH400, manufactured by Nippon Denshoku Industries Co., Ltd.). (iii) Viscosity average molecular weight The specific viscosity (η) is calculated using the following formula. SP The viscosity was determined using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of the sample in 100 mL of methylene chloride at 20°C. Specific viscosity (η SP ) = (t-t0) / t0 [t0 is the number of seconds for the methylene chloride to fall, and t is the number of seconds for the sample solution to fall.] The obtained specific viscosity was inserted into the following formula to determine the viscosity-average molecular weight Mv. η SP / c = [η] + 0.45 × [η] 2 c (where [η] is the intrinsic viscosity) [η] = 1.23×10 -4 M 0.83 c = 0.7 (iv) Flame retardancy The vertical burning test of UL standard 94 was carried out at a thickness of 1.6 mm, and its grade was evaluated. In addition, when the judgment could not meet any of the criteria of V-0, V-1, and V-2, it was indicated as "notV" here.

[0038] 《PC-A》 Pellets of polycarbonate (trade name: Panlite L-1225, manufactured by Teijin Limited) were pulverized using a DAS type pulverizer (DAS-14 manufactured by Daiko Co., Ltd.).

[0039] 《PC-M》 173.24 parts by mass of bisphenol M (the compound of formula (2)), 112.47 parts by mass of diphenyl carbonate, and 8.4×10- 4 parts by mass of potassium hydroxide at a concentration of 12.5 mmol / L and 4.6×10- 3 parts by mass of tetramethylammonium hydroxide at a concentration of 274 mmol / L were added, heated to 180 °C under a nitrogen atmosphere and melted. Then, the degree of vacuum was adjusted to 13.4 kPa over 五分钟. Then, the temperature was raised to 270 °C at a heating rate of 45 °C / hr. During that time, the pressure was also gradually reduced to 1 kPa. Then, the temperature was raised to reach 280 and the degree of vacuum was reduced to 100 Pa. The polymerization reaction was carried out until a predetermined power was reached, and after the reaction was completed, the resin mass was taken out from the flask. The taken-out resin mass was pulverized using a DAS type pulverizer (DAS-14 manufactured by Daiko Co., Ltd.).

[0040] [Examples 1 to 3, Comparative Examples 1 to 2] Flame-retardant aromatic polycarbonate resin compositions with the blending ratios listed in Table 1 were prepared as follows. For Example 1, the above PC-M was used, and for the others, each component in the ratios listed in Table 1 was weighed and uniformly mixed, and the mixture was fed into an extruder. A small kneader MC15HT (Xplore Instruments) was used as the extruder. The extruded resin composition was extruded under conditions of a cylinder temperature of 220 to 255°C, and the molten resin composition was used to form test specimens for vertical flame retardancy evaluation using an injection molding machine (injection molding machine IM12 (Xplore Instruments)) at a cylinder temperature of 220 to 255°C and a mold temperature of 70 to 85°C. In addition, 2 mm thick test specimens for transmittance measurement were formed using a vacuum compression molding machine (SFV-10, manufactured by Shinto Metal Industries Co., Ltd.) with the resin composition extracted by kneading and extruding in the small kneader. The evaluation results are shown in Table 1.

[0041] [Table 1]

[0042] From the comparison of the examples and comparative examples in Table 1, it can be seen that the flame-retardant aromatic polycarbonate resin composition of the present invention exhibits high flame retardancy even without the presence of a flame retardant, as well as good heat resistance and transparency. Furthermore, in Examples 1 and 2, since there is only one Tg, it is considered that PC-A and PC-M are compatible. [Industrial applicability]

[0043] The flame-retardant aromatic polycarbonate resin composition of the present invention possesses flame retardancy without the need for a flame retardant by containing a specific proportion of polycarbonate resin with a specific structure. This property is not found in conventional flame-retardant aromatic polycarbonate resin compositions. Therefore, the flame-retardant aromatic polycarbonate resin composition of the present invention is extremely useful not only for lighting covers and protective covers for transmissive displays, but also for various industrial applications in fields such as office automation equipment and electrical and electronic equipment, and the industrial effects it provides are extremely significant.

Claims

1. A flame-retardant aromatic polycarbonate resin composition comprising an aromatic polycarbonate resin (PC-A) obtained with the following formula (1) as the divalent phenol component and an aromatic polycarbonate resin (PC-M) obtained with the following formula (2) as the divalent phenol component, characterized in that the mass ratio (%) of PC-A to PC-M is 0 to 20:100 to 80. 【Chemistry 1】 【Chemistry 2】

2. The flame-retardant aromatic polycarbonate resin composition according to claim 1, wherein the viscosity-average molecular weight of the aromatic polycarbonate resin (PC-A) is in the range of 10,000 to 40,000.

3. The flame-retardant aromatic polycarbonate resin composition according to claim 1, wherein the viscosity-average molecular weight of the aromatic polycarbonate resin (PC-M) is in the range of 10,000 to 40,000.

4. A flame-retardant aromatic polycarbonate resin composition according to claim 1, for use in 3D printers.

5. The flame-retardant aromatic polycarbonate resin composition according to claim 4, used for a 3D printer having a filament shape with a diameter of 0.2 to 5.0 mm.

6. A molded article formed from the flame-retardant aromatic polycarbonate resin composition described in claim 1.

7. The molded product according to claim 6, wherein the molded product is a 3D printed product.

8. The molded article according to claim 7, wherein the molded article is a 3D printed article formed by a fused deposition modeling method.

9. A flame-retardant insulating sheet or film formed from the flame-retardant aromatic polycarbonate resin composition described in claim 1.

10. Electrical and electronic equipment using the flame-retardant insulating sheet or film described in claim 9.

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