JP2006008744A - Method for producing molded article of aromatic polycarbonate resin composition and molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a molded article having excellent appearance from an aromatic polycarbonate composition containing a solid inorganic compound, and to provide the molded article. <P>SOLUTION: An aromatic polycarbonate composition, which comprises 100 pts. mass of a resin component (A) mainly composed of an aromatic polycarbonate, 0.1-200 pts. mass of a solid inorganic compound (B) and 0.001-3 pts. mass of at least one compound (C) selected from the group consisting of organic acids, organic acid esters, organic acid anhydrides, organic acid phosphonium salts and organic acid ammonium salts, is injection molded. The method for producing the injection molded article comprises metering a molten resin after a first injection step of the molten resin and proceeding to a second injection step in the condition that the volume increase ratio of the metering section is 10% or less. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a production method and a molded body for obtaining a molded body having excellent appearance characteristics when manufacturing a molded body of an aromatic polycarbonate resin composition containing a solid inorganic compound. More specifically, a production method for obtaining an aromatic polycarbonate resin composition containing a solid inorganic compound with improved mechanical properties such as rigidity and strength, or performance such as flame retardancy as a molded article having excellent appearance characteristics And a molded body.

Aromatic polycarbonate is a resin material with excellent mechanical properties such as impact resistance and heat resistance, so it can be used as a housing material for computers such as desktop computers and notebook computers, printers, word processors, and copiers. And parts materials, automobile exterior parts, automobile interior parts, etc.
In recent years, high rigidity and dimensional accuracy are required for aromatic polycarbonates because molded articles made of aromatic polycarbonates are particularly prone to deformation due to external stress and deformation due to internal parts, especially for automotive parts. Furthermore, in the case of automobile interior and exterior parts, excellent appearance characteristics are required regardless of the presence or absence of coating.

On the other hand, when it is used for a housing related to an electrical component, there is a strong demand for thickness reduction for the purpose of weight reduction.
In order to improve the rigidity and dimensional accuracy of an aromatic polycarbonate, a method of blending an inorganic compound such as glass fiber, carbon fiber, talc, mica, wollastonite, etc. into the polycarbonate as a reinforcing material and / or filler has been attempted. Yes.
However, the aromatic polycarbonate resin composition containing these inorganic compounds has a problem in that degradation of the aromatic polycarbonate is promoted by the inorganic compound during the molding process. In particular, when a basic inorganic compound such as talc or mica is used, there is a problem that the melt stability of the aromatic polycarbonate is remarkably lowered and the physical properties of the material are greatly impaired.

With respect to this problem, JP-A-2-283760 of Patent Document 1 uses a phosphorus compound together, JP-A-3-21664 of Patent Document 2 uses an organic acid together, and Patent Document 3 discloses a method for suppressing a decrease in the molecular weight of an aromatic polycarbonate by using a sulfonic acid phosphonium salt in combination, but in these methods, melt stability, particularly at high temperatures, is proposed. Insufficient melt stability of this material has a problem that the molding processing temperature range is limited.
On the other hand, aromatic polycarbonate resin compositions used for OA equipment and electrical / electronic equipment are required not only to have high rigidity and dimensional accuracy, but also to have high flame retardancy. Recently, due to environmental considerations, As a flame retardant, there is a demand for a molded body of a flame retardant aromatic polycarbonate resin composition that does not use a bromine-based compound or a phosphorus-based compound.

In JP-A-2002-80709 of Patent Document 4, a 0.8 mm-thick test piece is used in a resin composition in which an inorganic filler, an organic phosphorus compound flame retardant, and an organic acid alkali metal salt are blended with an aromatic polycarbonate. V-0 is achieved in the UL94 standard, but a phosphorus-based flame retardant is used, and a molded body using the composition has a drawback that the physical properties are significantly lowered under high temperature and high humidity. .
In JP-A-2003-82218 and JP-A-2003-268226 of Patent Document 5, an organic acid metal salt, an alkoxysilane compound, a fluorine-containing polymer, an inorganic filler, and optionally an organic siloxane with respect to an aromatic polycarbonate. A resin composition containing a compound is disclosed. When the organosiloxane compound is blended, the composition achieves V-0 in the UL94 standard on a test piece having a thickness of 0.8 mm, but is high because the thermal stability of the organosiloxane compound is insufficient. There are drawbacks such as easy discoloration at the molten resin temperature and increased generation of volatile components.

JP-A-2003-82218 of Patent Document 5 and JP-A-2003-268226 of Patent Document 6 disclose a resin composition in which a fluorine-containing resin and a silicate compound are blended with an aromatic polycarbonate. However, the flame retardancy and melt stability of the composition are not sufficient.
That is, in the prior art, it is an aromatic polycarbonate resin composition containing an inorganic compound, and without using a bromine-based compound or a phosphorus-based compound as a flame retardant, high flame retardancy in a thin molded article (for example, Aromatic polycarbonate resin composition with a product thickness of less than 0.7mm, high flame retardancy that can achieve V-0 in the UL94 standard), and excellent melt stability and mechanical strength as a molding material A thin molded article made of a product has not yet been obtained, and its development has been desired.
Japanese Patent Laid-Open No. 3-21664 of Patent Document 7 discloses a resin composition in which talc and an organic acid are blended with an aromatic polycarbonate. However, it has a problem of poor appearance withstanding the actual molding temperature. There is no description of a molding method capable of achieving sufficient appearance improvement while the definition of the organic acid that can be substantially solved is insufficient.

JP-A-2-283760 JP-A-3-21664 Japanese Patent Laid-Open No. 10-60248 JP 2002-80709 A JP 2003-82218 A JP 2003-268226 A JP-A-3-21664

  An object of the present invention is to obtain an aromatic polycarbonate resin composition containing a solid inorganic compound with improved mechanical properties such as rigidity and strength, or performance such as flame retardancy, as a molded article having excellent appearance characteristics. It is providing a manufacturing method and a molded object.

  The present inventors diligently studied in order to achieve the above problems. As a result, surprisingly, 100 parts by mass of resin component (A) mainly composed of aromatic polycarbonate, 0.1 to 200 parts by mass of solid inorganic compound (B), organic acid, organic acid ester, organic acid anhydride, organic When an aromatic polycarbonate resin composition containing 0.001 to 3 parts by mass of at least one compound (C) selected from the group consisting of acid phosphonium salts and organic acid ammonium salts is subjected to an injection molding method, the first of the molten resin After the injection process, the molten resin is weighed, and the process proceeds to the second injection process at a volume increase rate of 10% or less of the metering part, in other words, after the molten resin is weighed. It has been found that by using an injection molding method that shifts to the injection process while maintaining the pressure applied to the resin, it is possible to easily obtain a molded product with excellent mechanical properties and melt stability and a better appearance. It has completed the present invention.

  Also, the injection molding method is an organic resin component (A) 100 parts by mass mainly composed of aromatic polycarbonate, solid inorganic compound (B) 0.1-200 parts by mass, and vapor pressure at 140 ° C. is 380 mmHg or less. An aromatic polycarbonate resin composition containing 0.001 to 3 parts by mass of at least one compound (C) selected from the group consisting of acids, organic acid esters, organic acid anhydrides, organic acid phosphonium salts, and organic acid ammonium salts. The amount of the compound (C) is used for an aromatic polycarbonate resin composition in which the pH value of the mixture of the solid inorganic compound (B) and the compound (C) is 4 to 8. As a result, it was found that a molded product having a better appearance of the molded product can be easily obtained even at a molding temperature of polycarbonate as high as 250 ° C.The present invention has been completed based on these new findings.

Accordingly, one object of the present invention is to provide a composition that does not cause decomposition or strength reduction of a resin even when a solid inorganic compound is added in order to enhance additional performance such as rigidity, strength, or flame retardancy of the polycarbonate resin. Another object of the present invention is to provide a molding method for producing a molded article having an excellent appearance.
Another object of the present invention is to provide a molding method for obtaining a molded article having high flame retardancy and excellent appearance without using a bromine compound or a phosphorus compound as a flame retardant. In particular, according to the present invention, an aromatic polycarbonate having not only extremely high flame retardancy but also excellent melt stability, heat aging resistance, moist heat resistance, rigidity and impact resistance, even if it is a thin-walled molded article. The object is to provide a molded body.

Next, in order to facilitate understanding of the present invention, first, basic features and preferred embodiments of the invention will be listed.
That is, this invention is invention of the following 1-13.
1. 100 parts by mass of resin component (A) mainly composed of aromatic polycarbonate, 0.1 to 200 parts by mass of solid inorganic compound (B), organic acid, organic acid ester, organic acid anhydride, organic acid phosphonium salt, and organic acid ammonium When an aromatic polycarbonate resin composition containing 0.001 to 3 parts by mass of at least one compound (C) selected from the group consisting of salts is injection-molded, the molten resin is measured after the first injection step of the molten resin. And the method for producing an injection-molded article, wherein the process proceeds to the second injection step at a volume increase rate of 10% or less of the measuring section.
2. The above injection molding is characterized in that the nozzle of an injection molding machine used for the molding is provided with an on-off valve. A method for producing an injection-molded article according to 1.
3. The on-off valve is operated so that the pressure of the measured molten resin in the injection cylinder immediately before the opening of the on-off valve is 1 kgf / cm ² or more when the on-off valve is opened to shift to the injection process. 2. A method for producing an injection-molded article according to 1.
4). The injection molding is characterized in that the mold used for the injection molding has a hot runner. ~ 3. A method for producing an injection-molded article according to 1.
5. 3. The hot runner having a valve gate. A method for producing an injection-molded article according to 1.
6). The aromatic polycarbonate resin composition is characterized by using an aromatic resin composition containing 0.001 to 1 part by mass of at least one organic acid metal salt selected from an organic acid alkali metal salt and an alkaline earth metal salt. The above 1. ~ 5. A method for producing an injection-molded article according to 1.
7). The aromatic polycarbonate resin composition uses an aromatic resin composition containing 0.01 to 1 part by mass of a fluoropolymer. ~ 6. A method for producing an injection-molded article according to 1.
8). 8. The method for producing an injection-molded article as described in 1 to 7 above, wherein the aromatic polycarbonate resin composition uses an aromatic resin composition containing a colorant.
9. 9. The method for producing an injection-molded article as described in 1 to 8, wherein the aromatic polycarbonate resin composition uses an aromatic resin composition containing an ultraviolet absorber.
10. 9. The method for producing an injection-molded article as described in 1 to 8 above, wherein the aromatic resin composition is an aromatic resin composition containing a conductive filler.
11. 9. An injection-molded article characterized in that there is no appearance defect of silver streaks or flow marks on the surface of the molded article by the method for producing an injection-molded article described in 1 to 8 above.
12 11. The 11 injection molded product according to claim 11, wherein the injection molded product is a molded product for a housing.
13. 11. The injection molded article according to 11 above, wherein the injection molded article is a molded article for automobiles or automobile parts.

  Production method for obtaining an aromatic polycarbonate resin composition containing a solid inorganic compound with improved performance such as mechanical properties such as rigidity and strength or flame retardancy as a molded product having excellent appearance properties according to the present invention And a molded object can be provided.

Hereinafter, the invention will be described in detail.
In the present invention, the component (A) is a resin mainly composed of an aromatic polycarbonate. In the present invention, the resin mainly composed of aromatic polycarbonate means a resin in which the amount of aromatic polycarbonate in the resin exceeds 50 parts by mass when the total amount of the resin is 100 parts by mass. The component (A) may be an aromatic polycarbonate alone, and the component (A) may contain a thermoplastic resin other than the aromatic polycarbonate.
The aromatic polycarbonate preferably used as the component (A) of the present invention is an aromatic polycarbonate derived from an aromatic dihydroxy compound, and examples of the aromatic dihydroxy compound include 1,1-bis (4-hydroxy-t- Bis (hydroxyaryl) alkanes such as butylphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxy) Bis (hydroxyaryl) cycloalkanes such as phenyl) cyclohexane, dihydroxyaryl ethers such as 4,4′-dihydroxy-3,3′-dimethylphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′- Dihydroxy-3,3'-dimethylphenylsulfur Dihydroxyaryl sulfides such as 4,4'-dihydroxydiphenylsulfoxide, dihydroxyaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethylphenylsulfoxide, 4,4'-dihydroxydiphenylsulfone, 4 , 4′-dihydroxy-3, 3′-dimethylphenylsulfone and the like.

  Among these, 2,2-bis (4-hydroxyphenyl) propane (common name, bisphenol A) is particularly preferable. These aromatic dihydroxy compounds can be used alone or in combination of two or more. As the aromatic polycarbonate preferably used as Component A of the present invention, those produced by a known method can be used. Specifically, a known method of reacting an aromatic dihydroxy compound and a carbonate precursor, for example, an interface in which an aromatic dihydroxy compound and a carbonate precursor (for example, phosgene) are reacted in the presence of an aqueous sodium hydroxide solution and a methylene chloride solvent. Solid-state polymerization of crystallized carbonate prepolymers obtained by polymerization methods (for example, phosgene method), transesterification methods (melting method) in which aromatic dihydroxy compounds react with carbonic acid diesters (for example, diphenyl carbonate), phosgene methods or melting methods A method manufactured by a method such as JP-A-1-15833, JP-A-1-271426, or JP-A-3-68627 can be used.

Particularly preferred as the aromatic polycarbonate used as the component (A) of the present invention is substantially free of chlorine atoms produced by a transesterification method from a dihydric phenol (aromatic dihydroxy compound) and a carbonic acid diester. Aromatic polycarbonate.
The weight average molecular weight (Mw) of the aromatic polycarbonate is usually 5,000 to 500,000, preferably 10,000 to 100,000, more preferably 13,000 to 50,000, still more preferably. Is 15,000 to 30,000, particularly preferably 17,000 to 25,000, and most preferably 17,000 to 20,000.

In the present invention, the weight average molecular weight (Mw) of the aromatic polycarbonate can be measured using gel permeation chromatography (GPC), using polystyrene gel with tetrahydrofuran as a solvent, and standard monodispersion. It can obtain | require using the conversion molecular weight calibration curve by the following Formula from the structural curve of polystyrene.
M _PC = 0.3591 M _PS 1.0388
( _MPC is the molecular weight of aromatic polycarbonate, _MPS is the molecular weight of polystyrene)
Further, as (A) of the present invention, two or more types of aromatic polycarbonates having different molecular weights may be used in combination. For example, an aromatic polycarbonate of an optical disk material whose Mw is usually in the range of 14,000 to 16,000, and an aromatic for injection molding or extrusion molding whose Mw is usually in the range of 20,000 to 50,000. A combination of polycarbonates can be used.

  Examples of the thermoplastic resin other than the aromatic polycarbonate that can be preferably used in the resin (A) mainly composed of the aromatic polycarbonate include polystyrene, high impact polystyrene (HIPS), and acrylonitrile / styrene resin (AS resin). , Butyl acrylate / acrylonitrile / styrene resin (BAAS resin), acrylonitrile / butadiene / styrene resin (ABS resin), methyl methacrylate / butadiene / styrene resin (MBS resin), butyl acrylate / acrylonitrile / styrene resin (AAS resin), polyethylene terephthalate Elastomers with improved impact resistance, such as polyester resins such as polyethylene and polybutylene terephthalate, polyamide resins, polymethyl methacrylate, polyarylate, and core / shell Chromatography, it may be mentioned thermoplastic resins such as a silicone elastomer. In particular, AS resin and BAAS resin are preferable for improving fluidity, ABS resin and MBS resin are preferable for improving impact resistance, and polyester resin is preferable for improving chemical resistance.

In the resin (A) mainly composed of the polycarbonate, the amount of the thermoplastic resin other than the aromatic polycarbonate is preferably 0.1 to 30 parts by mass, more preferably 100 parts by mass of the total amount of the component (A). Is 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass.
In the present invention, the component (B) is a solid inorganic compound.
In the present invention, by using the component (B), high flame retardancy of the resin composition can be obtained, and the rigidity and strength of the composition (function as a reinforcing material) and dimensional accuracy (filler) are improved. As a function).

Examples of the component (B) in the present invention include glass fiber, carbon fiber, aluminum borate whisker, calcium titanate whisker, rock wool, silicon nitride whisker, boron fiber, tetrapotted zinc oxide whisker, and wollastonite. be able to.
Examples of the plate-like component (B) include talc, mica, pearl mica, glass flakes, and kaolin.
Examples of the spherical (or pseudospherical) component (B) include glass beads, glass balloons, carbon black, glass powder, silica (natural silica and synthetic silica), and the like.

As the component (B) used in the present invention, a component whose surface is modified to improve the interface affinity with the aromatic polycarbonate in the resin composition of the present invention can also be used. The surface modification mentioned here can be performed by a method of adsorbing a new oily organic compound in advance or a method of treating with a silane coupling agent or a titanate coupling agent.
In the present invention, as the component (B), silicate compounds such as carbon fiber or talc, mica, pearl mica, wollastonite, kaolin, glass fiber, and glass flake are preferable.
Among the silicate compounds that can be more preferably used as the component (B) of the present invention, a particularly preferred silicate compound is a silicate compound composed of a metal oxide component and a SiO ₂ component. The form of the silicate ion present in the silicate compound that can be used as the component (B) may be any form such as orthosilicate, disilicate, cyclic silicate, chain silicate, layered silicate, and the like.

The silicate compound may be a compound oxide, an oxyacid salt, or a solid solution compound, and the compound oxide may be a combination of two or more different single oxides, and a single oxide and an oxyacid salt. Any of the combinations may be used, and the solid solution may be a solid solution of two or more different metal oxides and a solid solution of two or more different oxyacid salts.
The silicate compound may be a hydrate. The form of crystal water in the hydrate is included as hydrogen silicate ions in the form of Si—OH, included as hydroxide ions (OH ⁻ ) relative to metal cations, and included as water molecules in the gaps in the structure. Any of these may be used.

Moreover, both the natural product and the artificial synthetic product can be used as the silicate compound. As the artificial compound, silicate compounds obtained from various conventionally known methods, for example, various synthesis methods using a solid reaction, a hydrothermal reaction, an ultrahigh pressure reaction and the like can be used.
The silicate compound particularly preferably used as the component (B) of the present invention preferably has a composition substantially represented by the following formula (1).
xMO.ySiO ₂ .zH ₂ O (1)
(Here, x and y represent natural numbers, z represents an integer of 0 or more, MO represents a metal oxide component, and a plurality of different metal oxide components may be used.)
Examples of the metal M in the metal oxide MO include potassium, sodium, lithium, barium, calcium, zinc, manganese, iron, cobalt, magnesium, zirconium, aluminum, titanium, and the like.

The silicate compound of the above formula (1) preferably contains CaO and / or MgO as the metal oxide MO, more preferably contains only CaO and / or MgO, and substantially contains only MgO. It is particularly preferable to include it.
Specific examples of the silicate compound preferably used as the component (B) of the present invention include talc, mica, wollastonite, zonotlite, kaolin clay, montmorillonite, bentonite, sepiolite, imogolite, sericite, lawsonite, smectite and the like. be able to.
In addition, as described above, the silicate compound can be of any shape (plate, needle, sphere, fiber, etc.), but plate, needle and fiber are preferred, What is a plate-like particle | grain can be most preferably used as a component (B) of this invention. Here, the plate-like particles are obtained by the following method when the average particle diameter obtained as the median diameter of the plate-like component (B) is (a) and the thickness is (c), ) / (C) ratio is 5 to 500, preferably 10 to 300, more preferably 20 to 200.

In the present invention, the average particle size (a) of the component (B) is preferably 0.001 to 500 μm, more preferably 0.01 to 100 μm, still more preferably 0.1 to 50 μm, and particularly preferably 1 to 30 μm. preferable.
In addition, said average particle diameter is measured using either of the following two methods by the approximate distribution range of the particle diameter of a component (B).
When the particle diameter of the component (B) is distributed in the range of about 0.001 to 0.1 μm, an observation photograph of a transmission electron microscope is taken, and from the obtained micrograph, 100 or more in the resin composition For each inorganic compound particle, the area of each particle on the photograph was measured, and using S (value obtained by dividing the area on the photograph by the magnification of the microscope) (4S / π) ^{0. 5} is determined as the particle diameter of each particle, and the number average particle diameter is defined as the average particle diameter (a).

When the particle diameter of the component (B) is approximately 0.1 to 300 μm, the particle diameter is measured by a laser diffraction method (for example, using SALD-2000 manufactured by Shimadzu, Japan), and the median diameter is determined. Average particle diameter.
In the present invention, the thickness (c) of the plate-like component (B) is preferably 0.01 to 100 μm, more preferably 0.03 to 10 μm, further preferably 0.05 to 5 μm, and 0.1 to 3 μm. Particularly preferred.
The thickness (c) of the plate-like particles used as the component (B) is obtained, for example, by taking an observation photograph of a transmission electron microscope, and from the obtained micrograph, with respect to 10 or more individual particles in the resin composition. The thickness of each particle on the photograph is measured, the value obtained by dividing the thickness on the photograph by the magnification of the microscope is obtained as the thickness of each particle, and the average value is defined as the thickness (c).

Of the plate-like silicate compounds that can be used as the component (B) of the present invention, particularly preferred are talc and mica.
Talc that can be particularly preferably used as the component (B) of the present invention is a hydrous magnesium silicate having a layered structure, represented by the chemical formula 4SiO ₂ .3MgO.H ₂ O, usually about 63 mass% SiO ₂ , MgO It contains about 32% by mass, about 5% by mass of H ₂ O, other Fe ₂ O ₃ , CaO, Al ₂ O _{3 and the} like, and the specific gravity is about 2.7.
As the component (B) of the present invention, calcined talc, talc from which impurities have been removed by washing with an acid such as hydrochloric acid or sulfuric acid can be preferably used. Furthermore, talc that has been subjected to surface hydrophobic treatment with a silane coupling agent, a titanate coupling agent, or the like can also be used.

On the other hand, mica that can be particularly preferably used as the component (B) of the present invention is a pulverized product of a silicate mineral containing aluminum, potassium, magnesium, sodium, iron and the like. Mica includes muscovite (mass cobalt, chemical formula: K (AlSi ₃ O ₁₀ ) (OH) 2 Al ₄ (AlSi ₃ O ₁₀ ) K), phlogopite (phlogopite, chemical formula K (AlSi ₃ O ₁₀ ) (OH) ₂ Mg ₆ (OH) ₂ (AlSi ₃ O ₁₀ ) K), biotite (biotite, chemical formula K (AlSi ₃ O ₁₀ ) (OH) ₂ (Mg, Fe) ₆ (OH) ₂ (AlSi ₃ O ₁₀ ) K) , Artificial mica (fluorine phlogopite, chemical formula K (AlSi ₃ O ₁₀ ) (OH) ₂ F ₂ Mg ₆ F ₂ (AlSi ₃ O ₁₀ ) K), etc., and any mica can be used in the present invention, Preference is given to muscovite.

Such mica may be subjected to a surface hydrophobic treatment with a silane coupling agent, a titanate coupling agent or the like.
In this invention, the usage-amount of a component (B) is 0.1-200 mass parts with respect to 100 mass parts of components (A), 0.3-100 mass parts is preferable, 0.5-50 mass parts is More preferably, 0.8-30 mass parts is still more preferable, and 1-20 mass parts is especially preferable. When a component (B) exceeds 200 mass parts, the fall of melt stability becomes remarkable and the fall of the mechanical physical property of a resin composition is large. Moreover, when a component (B) is less than 0.1 mass part, it exists in the tendency for the flame retardance of a resin composition to fall, and the high flame retardance which is one of the objectives of this invention cannot be achieved.

In the present invention, as the component (B), in the case of using a plate-like form, for example, talc and mica, it is possible to achieve particularly excellent flame retardancy even if it is a thin-walled molded article, and a resin. Since the electrical properties such as impact resistance, dimensional stability, insulation and tracking resistance of the composition can be improved, it is most preferable as an embodiment of the present invention.
Component (C) used in the present invention is at least one compound selected from the group consisting of organic acids, organic acid esters, organic acid anhydrides, organic acid phosphonium salts, and organic acid ammonium salts. Component (C) is preferably a compound having a vapor pressure at 140 ° C. of 380 mmHg or less.

In this invention, the usage-amount of a component (C) is 0.001-3 mass parts with respect to 100 mass parts of components (A), 0.005-2 mass parts is preferable, 0.01-1 mass part is More preferably, 0.05-0.8 mass part is still more preferable, and 0.08-0.5 mass part is especially preferable. When the component (C) exceeds 3 parts by mass or less than 0.001 parts by mass, the melt stability is remarkably lowered, the mechanical properties of the resin composition are greatly reduced, and the resin composition is difficult. The flame retardancy tends to decrease, and the high flame retardancy targeted by the present invention cannot be achieved.
In the present invention, component (C) is used in combination with component (B), and the amount of component (C) used is such that the pH value of the mixture of component (B) and component (C) is in the range of 4-8. By adjusting in this way, the flame retardance and melt stability of the resin composition can be dramatically improved, which is particularly preferable.

The organic acid used as component (C) of the present invention is an organic compound containing at least one group selected from the group consisting of -SO ₃ H group, -COOH group, and -POH group in the molecular structure, ie, organic Sulfonic acid, organic carboxylic acid, and organic phosphoric acid. Of these, organic sulfonic acids and organic carboxylic acids are preferred in the present invention, and organic sulfonic acids are particularly preferred.
The organic acid ester, organic acid anhydride, organic acid phosphonium salt, and organic acid ammonium salt used as the component (C) of the present invention are derivatives of the above organic acids. The organic acid derivative is considered to decompose when the resin composition is molded and function as an acid. Therefore, for example, when an inorganic compound showing basicity is used as the component (B), the component (C) is considered to exhibit a function of neutralizing it. That is, in the composition of the present invention, the component (C) exhibits a pH adjusting function.

As the compound (C), not only a low molecular compound such as a monomer but also an oligomer or polymer can be used. In the present invention, the component (C) can be used in combination of two or more. As component (C) of the present invention, an organic sulfonic acid derivative selected from organic sulfonic acid and / or organic sulfonic acid ester, organic sulfonic acid phosphonium salt, organic sulfonic acid ammonium salt, and organic carboxylic acid are preferably used. it can.
In particular, when an organic sulfonic acid and / or an organic sulfonic acid ester is used as the component (C), the melt stability of the resin composition is particularly excellent, and the generation of volatile components can be suppressed to a low level. In addition, the molding process can be performed in a wide temperature range, and the appearance of the molded product is extremely excellent.

As the organic sulfonic acid that can be preferably used as the component (C) of the present invention, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid, diisobutylnaphthalenesulfonic acid, dodecylbenzene Examples thereof include directional sulfonic acids such as sulfonic acids, aliphatic sulfonic acids having 8 to 18 carbon atoms, sulfonated polystyrene, polymers such as methyl acrylate / sulfonated styrene copolymers, and oligomeric organic sulfonic acids. .
Further, in the present invention, the organic sulfonic acid preferably used as the component (C) contains —OH 3 group, —NH ₂ group, —COOH group, halogen group and the like in addition to —SO ₃ H group in the molecular structure. An organic sulfonic acid compound may be used, for example, naphthol sulfonic acid, sulfamic acid, naphthylamine sulfonic acid, sulfobenzoic acid, organic sulfonic acid that is fully or partially substituted with a chloro group (chlorinated organic sulfonic acid), fluoro group And organic sulfonic acids (fluoro group-containing organic sulfonic acids) which are completely or partially substituted by the above.

As the component (C) used in the present invention, an aromatic sulfonic acid compound is particularly preferable, and benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid and the like can be mentioned as the most preferable examples.
In the present invention, an amount in which the pH value of the mixture of component (B) and component (C) is in the range of 4 to 8 is preferable, but in the present invention, the pH value can be measured based on JIS K5101. .
In the method for measuring the pH value of JIS K5101, there are a boiling method and a room temperature method as operation methods. In the present invention, the boiling method is used.
In the measurement of the pH value of the mixture of component (B) and component (C) in the present invention, if the solubility of component (C) in water is low, alcohols such as ethanol and isopropyl alcohol are dispersed in the suspension. Used as an agent.
The amount of the component (C) used in the present invention varies depending on the type, shape and amount of the component (B) or the type of the component (C).
The amount of component (C) used is more preferably such that the pH of the mixture of component (B) and component (C) is in the range of 4.2 to 7.8, More preferably, it is in the range.

The injection molding according to the present invention is preferably a method for producing an injection-molded product, wherein the nozzle of an injection molding machine used for molding is provided with an on-off valve.
In the present invention, the measurement of the molten resin means that the screw in the cylinder in the injection molding machine is moved backward to fill the mold after filling the mold of the molten resin in the injection molding, and a desired amount of the molten resin is measured at the front of the cylinder. Indicates what to do.
In the present invention, the volume increase rate of the measuring unit after measuring the molten resin is the measuring unit when the volume of the measuring unit immediately after measuring the resin is V1, and then the screw is retracted without supplying the molten resin. The volume increase rate (V2-V1) / V1 when the volume of V is V2.
In the present invention, the volume increase rate of the measuring portion is 10% or less, preferably 7% or less, more preferably 5% or less, still more preferably 3% or less, and most preferably the substantial volume increase rate is 0%.

During the measurement of the molten resin, the screw is moved backward while being rotated, and the molten resin is conveyed forward. At that time, in order to discharge gas, vapor, etc. from the molten resin, a pressure generally called back pressure is measured. To the molten resin. Backpressure, depending on conditions, generally at a resin pressure of 10 kgf / cm ² or more 1000 kgf / cm ² or less, preferably 50 kgf / cm ² or more 800 kgf / cm ² or less, more preferably, 100 kgf / cm ² or more 500 kgf / cm ² or less. The resin weighed while being applied with back pressure is stored in the metering portion at the tip of the cylinder. At the time of metering, the tip of the nozzle is pressed against the mold sprue bush and pressure is applied to the tip. When the nozzle is backed while pressure is applied to the nozzle tip or the solidified sprue present in the previous step is removed, the molten resin measured from the nozzle tip is discharged depending on the material. May occur.

The following two methods are often used as a general method for preventing this “sag”. As a first method, there is a method of sucking back the screw slightly to the rear of the cylinder in order to relieve the pressure of the resin under pressure after completion of the measurement. In general, the amount of suck back depends on the size of the molding machine, but is generally about 5 to 10 mm. This suckback increases the volume of the measuring section. In the present invention, the rate of increase in the volume of the measuring portion increases as the suck back amount increases.
The second method is a method of preventing the molten resin from being discharged by providing an opening / closing valve at the nozzle tip so that the resin is not discharged from the nozzle tip during or after weighing. As an example of a nozzle provided with an on-off valve, a “shutoff nozzle” is generally used. As the shutoff nozzle on-off valve, a valve using power such as air pressure or hydraulic pressure, a valve using mechanical elastic force such as a spring, or the like can be used. When a shut-off nozzle is used, the on-off valve at the nozzle tip is closed immediately after resin weighing without performing suck back, so the volume increase rate of the metering section in the present invention is 0%.

The second injection step in the present invention is a next injection step measured at a predetermined volume increase rate of the metering unit, that is, a step of advancing the injection cylinder to inject and fill the molten resin of the metering unit into the mold. Indicates.
When opening the on-off valve in the present invention, the measured pressure of the molten resin in the injection cylinder immediately before opening the on-off valve is 1 kgf / cm ² or more means that the back pressure applied to the molten resin is not completely released. Preferably, it is 10 kgf / cm ² or more, more preferably 50 kgf / cm ² or more.
In the present invention, the hot runner installed in the mold to be used is preferably a hot runner having a runner portion provided with a heater in the mold, and more preferably, Those with a valve gate are desirable. The valve gate is an open / close valve provided at the gate at the tip of the hot runner.It functions in the same way as the shutoff valve of the nozzle, and opens when filling the resin into the cavity. Closed until injection. As a result, unnecessary leakage of the molten resin from the gate portion is prevented, so that an operation such as suck back is unnecessary, and the volume increase rate of the measuring portion can be suppressed.

The organic acid alkali metal salt and organic acid alkaline earth metal salt in the present invention have an action of promoting the decarboxylation reaction of the aromatic polycarbonate during combustion with respect to the resin (A) mainly composed of the aromatic polycarbonate.
The organic acid metal salt of the present invention is a metal salt of an organic sulfonic acid and / or a metal salt of a sulfate ester, and these can be used alone or in combination of two or more.
Examples of the alkaline earth metal contained in the organic acid metal salt of the present invention include lithium, sodium, potassium, rubidium and cesium, and examples of the alkaline earth metal include beryllium, magnesium, potassium, strontium and barium. In the present invention, particularly preferred alkali metals are lithium, sodium and potassium, and most preferred are sodium and potassium.

Examples of the metal salts of organic sulfonic acids that can be preferably used in the present invention include alkali / alkaline earth metal salts of aliphatic sulfonic acids, alkali / alkaline earth metal salts of aromatic sulfonic acids, and the like. In the present specification, the term “alkali / alkaline earth metal salt” is used to include both alkali metal salts and alkaline earth metal salts.
Alkali / alkaline earth metal salts of aliphatic sulfonic acids include alkali / alkali / alkaline earth metal salts of alkane sulfonic acids having 1 to 8 carbon atoms, or alkyls of alkali / alkaline earth metal salts of such alkane sulfonic acids. Alkali / alkaline earth metal salts of sulfonic acids in which a part of the groups are substituted with fluorine atoms, and alkali / alkaline earth metal salts of perfluoroalkanesulfonic acids having 1 to 8 carbon atoms can be preferably used. Particularly preferred specific examples include perfluoroethanesulfonic acid sodium salt and perfluorobutanesulfonic acid potassium salt.

Among the organic acid metal salts in the present invention, more preferred alkali / alkaline earth metal salts include alkali / alkaline earth metal salts of aromatic sulfonic acid and alkali / alkaline earth metal salts of perfluoroalkanesulfonic acid. be able to.
In this invention, the usage-amount of organic acid metal salt is 0.001-1 mass part with respect to 100 mass parts of component (A), 0.01-0.9 mass part is preferable, 0.1-0. 8 parts by mass is more preferable, and 0.4 to 0.7 is most preferable. When the organic metal salt exceeds 1 part by mass, the melt stability is remarkably lowered, and the mechanical properties of the resin composition are greatly lowered. Moreover, when it is less than 0.001 part by mass, the flame retardancy of the resin composition tends to decrease, and it is difficult to achieve high flame retardancy, which is one of the objects of the present invention.

The fluoropolymer that can be used in the present invention is used for the purpose of preventing dripping of combustion products. The fluoropolymer that can be preferably used in the present invention has a fibril forming ability, and a tetrafluoroethylene polymer of polytetrafluoroethylene or a tetrafluoroethylene / propylene copolymer can be preferably used, and is particularly preferable. Is polytetrafluoroethylene.
Fluoropolymer has various forms such as fine powder fluoropolymer, aqueous dispersion of fluoropolymer, powdered mixture with second resin such as acrylonitrile / styrene copolymer (AS) and polymethyl methacrylate (PMMA) The following fluoropolymers can be used.

As an aqueous dispersion of a fluoropolymer that can be preferably used in the present invention, “Teflon (registered trademark) 30J” manufactured by Mitsui DuPont Fluorochemical Co., Ltd., “Polyflon D-1 (registered trademark)” manufactured by Daikin Industries, Ltd., “Polyfluorocarbon” “D-2 (registered trademark)”, “Polyflon D-2C (registered trademark)”, “Polyflon D-2CE (registered trademark)” can be exemplified.
In the present invention, a fluoropolymer made into a powdery mixture with a second resin such as AS or PMMA can also be suitably used, but it relates to a fluoropolymer made into a powdery mixture with these second resins. The technology is disclosed in JP-A-9-95583, JP-A-11-49912, JP-A-2000-143966, JP-A-2000-297189, and the like. As a fluoropolymer in the form of a powder mixture with these second resins that can be preferably used in the present invention, “Blendex 499 (registered trademark)” manufactured by GE Specialty Chemicals, Inc., “Metablene A-3800 (registered trademark) manufactured by Mitsubishi Rayon Co., Ltd.” Trademark) ”.

The blending amount of the fluoropolymer that can be used in the present invention is 0.01 to 1 part by weight, preferably 0.05 to 0.8 part by weight, more preferably 0 to 100 parts by weight of the component (A). .1 to 0.7 parts by mass. When the fluoropolymer exceeds 1 part by mass, the mechanical properties of the resin composition tend to decrease. On the other hand, when the amount is less than 0.01 parts by mass, the combustion product tends to be dripped and the combustibility tends to decrease.
In the present invention, 100 parts by mass of a resin component (A) mainly composed of an aromatic polycarbonate, 0.1 to 200 parts by mass of a solid inorganic compound (B), an organic acid or an organic acid having a vapor pressure at 140 ° C. of 380 mmHg or less Fragrance containing 0.001 to 3 parts by mass of compound (C ′) more preferably specifying at least one component (C) selected from the group consisting of esters, organic acid anhydrides, organic acid phosphonium salts and organic acid ammonium salts A group polycarbonate resin composition is also provided. As the resin components (A) and (B), compounds similar to those described above can be used.

  Component (C ′) is at least one compound selected from the group consisting of organic acids, organic acid esters, organic acid anhydrides, organic acid phosphonium salts, and organic acid ammonium salts, and has a vapor pressure at 140 ° C. It can be selected from compounds of 380 mmHg or less, preferably 100 mmHg or less, more preferably 50 mmHg or less. When a compound having a high vapor pressure is used as the component (C ′), when used at a molding temperature of 250 ° C. or higher, such as polycarbonate, generally 280 ° C. or higher, sometimes 300 ° C. or higher, more strictly 320 ° C. or higher, or When the mold temperature is 60 ° C. or higher, generally 80 ° C. or higher, sometimes 100 ° C. or higher, and more strictly 120 ° C. or higher, when a compound having a low vapor pressure is used, it is easily vaporized and is the object of the present invention. There may be a problem that a high appearance and sufficient physical properties of the obtained molded product cannot be obtained.

Preferable specific examples of (C ′) include aromatic compounds having a low vapor pressure, aromatic sulfonic acid compounds are particularly preferable, and benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid and the like are the most preferable examples. I can list them.
As the organometallic salt and fluoropolymer used in the composition of the present invention, those selected from the aforementioned compounds can be used.
The colorant that can be used in the present invention is a pigment or dye used for coloring a resin. For example, inorganic pigments such as titanium white (titanium oxide), titanium yellow, bengara, ultramarine blue, spinel green, condensed azo Organic pigment, quinacridone organic pigment, isoindolinone organic pigment, perylene organic pigment, anthraquinone organic pigment, organic pigment such as phthalocyanine organic pigment, carbon black, perylene dye, perinone dye, anthraquinone Examples thereof include dyes and heterocyclic dyes.

Among the colorants, titanium oxide is not limited by the production method and crystal structure, but titanium oxide produced by the chlorine method and having a rutile crystal structure is preferred. Further, the titanium oxide as a colorant may be previously treated with a treatment agent usually used as a surface treatment agent for titanium oxide. Examples of such treatment agents include alumina and silica, and they can be used alone or in combination. Furthermore, it is also possible to include an organic dispersant, a stabilizer and the like as the surface treatment agent.
The ultraviolet absorber that can be used in the present invention is not particularly limited as long as it is generally used for polycarbonate resins, and examples thereof include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and hydroxyphenyltriazine compounds. can give. Further, in order to further improve the weather resistance, a hindered amine light stabilizer and various antioxidants may be included.

Examples of the benzophenone ultraviolet absorber include 2-hydroxy-4-n-dodecyloxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) Examples include methane.
Examples of the benzotriazole ultraviolet absorber include 2- (2H-benzotriazol-2-yl) -4- (1,1 ′, 3,3′-tetramethylbutyl) phenone and 2- (2H-benzotriazole-2). -Yl) -4,6bis (1-methyl-1-phenylethyl) phenol 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'- Diphenyl-tert-amylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenylbenzotriazole, 2,2′methylenebis [4- (1,1 , 3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol, methyl-3- [3-tert-butyl-5- (2H-benzotriazol) (Lu-2-yl) -4-hydroxyphenylpropionate-condensate with polyethylene glycol.

The conductive filler that can be used in the present invention is generally one or more types of resin selected from metal fibers, metal foils, metal powders, carbon powders, glass fibers coated with metal on the surface, and mica plated with metal. If it is used in order to improve electroconductivity, there will be no limitation in particular. Particularly preferred are carbon fibers, with a fiber diameter of 2 to 30 μm and a fiber length of 1 to 30 mm. As the carbon fiber, any of PAM type and pitch type can be used. The addition amount of the carbon fiber is 5 to 85 parts by mass, preferably 5 to 60 parts by mass with respect to 100 parts by mass of the resin component.
In the aromatic polycarbonate resin composition of the present invention, a lubricant, a release agent, a heat stabilizer, an antioxidant, an antistatic agent, and the like can be further added as necessary.

The usage-amount of the said additive is 5 mass parts or less normally with respect to 100 mass parts of total amounts of a resin composition, Preferably it is 3 mass parts or less, More preferably, it is 1 mass part or less.
Next, the manufacturing method of the aromatic polycarbonate resin composition of this invention is demonstrated.
The resin composition of the present invention is obtained by blending the above components (A) to (C ′) or (C), and other components as necessary in the above composition ratio, and melt-kneading such as an extruder. I can do it. At this time, blending of each component and melt kneading use a commonly used device, for example, a premixing device such as a tumbler or ribbon blender, a melt kneading device such as a single screw extruder, a twin screw extruder, or a kneader. I can do it. In addition, the raw materials can be supplied to the melt-kneading apparatus after the respective components are mixed in advance. It is also possible to supply each component independently to the melt-kneading apparatus.

In producing the aromatic polycarbonate resin composition of the present invention, the shape of the component (A) is not particularly limited, and examples thereof include pellets, powders, and flakes.
In the production of the resin composition of the present invention, the component (B) is preliminarily formed on the surface and inside of the component (C ′) or (C) via a covalent bond, an ionic bond, an intermolecular force, a hydrogen bond, or the like. Thus, it is preferable that the material is supplied to the melt-kneading apparatus after being chemically or physically surface-treated.

  As a method for subjecting the component (B) to surface treatment with the component (C ′) or (C) in advance, for example, the following method can be used. A predetermined amount of the component (C ′) or (C) is blended with the component (B), and if necessary, the component (C ′) or (C) is sprayed or dropped as a molten state, a solution state, or a gas state. The mixture is brought into contact with the component (B) by a method such as wetting or dipping, and mixed and stirred using a mechanical mixing device such as a Henschel mixer, Nauta mixer, V blender, or tumbler, and then the excess components are degassed and dried. A method for performing the processing can be exemplified. The mixing and stirring treatment may be performed at a temperature not higher than the melting point of the component (C ′) or (C), but may be performed by heating to a temperature not lower than the melting point of the component (C ′) or (C). More effective. The time required for the mixing and stirring is usually 1 minute to 3 hours, preferably 2 minutes to 1 hour, more preferably 3 minutes to 40 minutes, and further preferably 5 minutes to 30 minutes, depending on the type of mixing apparatus. . As a mixing device, a Henschel mixer with a heating device and a Nauta mixer can be used particularly preferably. In addition, it is preferable to remove the excess (C ′) or (C) component by depressurization and / or overheating after the mixing and stirring treatment and sufficiently dry.

  As a melt-kneading apparatus for producing the resin composition of the present invention, an extruder, preferably a twin-screw extruder is usually used. Component (B) can also be side-fed from the middle of the extruder. The melt-kneading is usually carried out by appropriately selecting the cylinder set temperature of the extruder at 200 to 300 ° C., preferably 220 to 270 ° C., and the extruder rotating speed of 100 to 700 rpm, preferably 200 to 500 rpm. However, care should be taken not to give excessive heat during melt-kneading. Furthermore, it is also effective to provide an opening in the latter part of the extruder and perform open devolatilization and, if necessary, vacuum devolatilization. Further, the residence time of the raw material resin in the extruder is usually selected appropriately within a range of 10 to 60 seconds.

  The molding method for obtaining the molded article comprising the aromatic polycarbonate resin composition of the present invention may be a normal molding method, such as general extrusion molding, profile extrusion molding, sheet extrusion, inflation molding, calendar molding, injection molding, compression molding. Injection compression molding and blow molding can also be used. In particular, injection molding and injection compression molding are preferably used to obtain a thin molded body. In the case of injection molding, as a special technique for producing a thin molded article, a method of improving the fluidity of the molten resin by dissolving nitrogen or carbon dioxide as a plasticizer in the molten resin may be used. Nitrogen and carbon dioxide may be appropriately injected by providing a vent portion in an injection molding machine cylinder. In order to improve the transferability of molded products and to prevent defects in appearance (swirl marks) when filling the mold with a resin in which nitrogen or carbon dioxide is dissolved in the molten resin, the molten resin is made of gold. Before filling the mold, nitrogen gas or carbon dioxide may be filled in the mold in advance. In this case, carbon dioxide is preferably used for the purpose of improving transferability. Further, the foamed molded body may be molded using a chemical foaming agent such as azo compound or baking soda or a physical foaming agent such as nitrogen or carbon dioxide in order to foam the molded body during extrusion molding or injection molding.

Further, the present invention can also provide a molded article having a high appearance with no appearance defects such as silver streaks and flow marks on the surface of the molded article.
Examples of the molded article of the present invention are used for computer parts such as desktop personal computers and notebook personal computers, mobile phone parts, electric / electronic devices, portable information terminals, home appliance parts, and the like. In particular, examples of the thin molded sheet include an insulating film and an insulating sheet. Furthermore, battery cases, plastic frames, and the like, for which demands for thin molded articles have been increasing in recent years, can also be mentioned as suitable applications.
Further, it can be used as exterior parts such as door peripheral panels, doors and fenders as automobile and vehicle parts, and internal members such as instrument panels.

Hereinafter, in the Examples and Comparative Examples, the following components (A), (B), (C) and other components were used, and molded articles were prepared using the aromatic polycarbonate resin composition.
1. Component (A): Aromatic polycarbonate A bisphenol A-based polycarbonate produced from bisphenol A and diphenyl carbonate by a melt transesterification method, and octadecyl-3- (3,5-di-) as a hindered phenol-based antioxidant. Containing 300 ppm of (butyl-4-hydroxyphenyl) propionate.
Mass average molecular weight (Mw) = 21,800
Phenolic end group ratio (ratio of phenolic end groups to the total number of end groups) = 35 mol%
The phenolic end group ratio was measured by a nuclear group magnetic resonance method (NMR method).

2. Component (B): Solid inorganic compound Talc having the following characteristics.
Average particle size = 5 μm
Whiteness = 96%
Bulk specific volume = 2.3 ml / g
Specific surface area = 8.5 m <2> / g
Moisture = 0.2%
Oil absorption = 51ml / 100g
pH = 9.3
The average particle size was measured using a SALD-2000 analyzer manufactured by Shimadzu Corporation, the particle size of each particle was measured by a laser diffraction method, and the average particle size of talc was the median size.
The whiteness was measured by a measuring method based on JIS P8123, and measured with a digital hunter ST manufactured by Toyo Seiki Seisakusho.
The specific surface area was measured by a BET method using a gas phase adsorption method, and was measured using a flow soap 2300 manufactured by Shimadzu Corporation.
The moisture was measured by a measuring method based on JISK 5101 and measured using STAC-5100 manufactured by Shimadzu Corporation.
The oil absorption and the volume specific volume were measured by a measuring method based on JIS K5101.
The pH was measured by a pH measurement method (boiling method) based on JIS K5101 standard.

3. Component (C): at least one compound selected from the group consisting of organic acids, organic acid esters, organic acid anhydrides, organic acid phosnium salts, and organic acid ammonium salts p-toluenesulfonic acid having a vapor pressure of 20 mmHg at 140 ° C. (Special grade reagent, Wako Pure Chemical Industries, Ltd.)

4). Other compositions (organic metal salts)
At least one organic acid metal salt selected from organic acid alkali metal salts and organic acid alkaline earth metal salts Perfluorobutanesulfonic acid potassium salt (trade name “Megafax F114” manufactured by Dainippon Ink and Chemicals, Inc.)
(Anti-dripping agent)
Fluoropolymer Polytetrafluoroethylene (PTFE) and acrylonitrile / styrene copolymer (AS) 50/50 (mass ratio) powdery mixture (“Blendex 449” (registered trademark), manufactured by GE Specialty Chemicals, USA)
(UV absorber)
A benzotriazole-based 2- (2H-benzotriazol-2-yl) -4- (1,1 ′, 3,3′-tetramethylbutyl) phenone was used. ("Eversorb72" manufactured by Eiko Chemical Co., Ltd.)
(Carbon fiber)
Carbon fiber with a diameter of 7μm and a fiber length of 6mm (release agent)
Pentaerythritol tetrastearate (manufactured by Nippon Oil & Fats Co., Ltd., “Unistar H476” (registered trademark))
(Coloring agent)
Carbon black "Mitsubishi Carbon # 50" manufactured by Mitsubishi Chemical Corporation as a black colorant
Titanium oxide "Tioxide TR28" manufactured by Huntsman as a white colorant

"Examples 1-5" and "Comparative Examples 1-3"
Components (A), (B), (C) and other components were melt-kneaded in the amounts shown in Table 1 (units are parts by mass) using a twin screw extruder to obtain a polycarbonate flame retardant resin composition. . Specific production methods and production conditions are as follows.
As a result of measuring the pH value of the mixture of the component (B) and the component (C) having the composition ratios shown in Table 1 in accordance with JIS K5101, the values shown in Table 1 were obtained. The melt kneading apparatus uses a twin screw extruder (ZSK-25, L / D = 37, manufactured by Werner & Pfleiderer, Germany), a cylinder set temperature of 250 ° C., a screw rotation speed of 250 rpm, and a kneading resin discharge speed of 15 kg / hr. Melt kneading was performed under the conditions.
During melt kneading, the temperature of the molten resin measured by a thermocouple at the extruder die was 260 to 270 ° C. In addition, a vent port was provided in the latter part of the extruder, and vacuum devolatilization (0.005 MPa) was performed. The raw materials are charged into the twin-screw extruder when the components (B) and (C) are mixed in a 10-liter Henschel mixer set at a jacket temperature of 200 ° C. at the blending ratio shown in Table 1 before melt kneading. It was used after being premixed for 10 minutes with a screw rotation of 1,450 rpm. When the pH value of the premixing treatment was measured according to JIS K5101, the results shown in Table 1 and Table 2 were obtained. The obtained pellets of the resin composition were dried at 120 ° C. for 4 hours, molded with an injection molding machine, and the following tests were performed.

Flame Retardancy Test A strip-like thin molded article (thickness: 0.75 mm) for a combustion test was prepared as a test piece. The gate was filled with resin so that the tip of the molded product was oriented from a fan gate having a width of 20 mm located at the center in the longitudinal direction of the molded product.
The injection molding machine used was TR50S2A manufactured by Sodick, and was molded under conditions of a cylinder set temperature of 320 ° C., a mold temperature of 110 ° C., and an injection speed of 400 mm / sec. The molded product was held for 2 days in an environment of a temperature of 23 ° C. and a humidity of 50%, and then subjected to a 50 W (20 mm) vertical combustion test according to the UL94 standard, and V-0, V-1, V-2, NC ( NC was classified as non-classification.
Inflammability degree (left is good): V-0>V-1>V-2> NC.

  As a molded product for evaluating the appearance, a cup-shaped molded product having an outer diameter of 80 mm, an inner diameter of 75 mm, a height of 45 mm, and a wall thickness of 2.5 mm was prepared. In the case of a cold runner, the runner was a direct gate at the center of the bottom of the cup-shaped molded product, and the gate diameter was 7 mm. As the injection molding machine, Fanuc 100D manufactured by FANUC was used, and molding was performed under conditions of a cylinder set temperature of 300 ° C. and a mold temperature of 100 ° C. The amount of screw back after weighing was 0 mm when using a shut-off nozzle, 0.3 mm in Experiment 4, 0 mm in Comparative Example 1, and 6 mm in Comparative Example 3 when using an open nozzle. did.

Examples and comparative examples will be described below.
In Example 1, the composition described in Table 1 was molded using a molding machine equipped with a shut-off nozzle. As a result, a molded article having a good appearance with no appearance defect such as a silver stream and a flow mark on the surface of the molded article was obtained. Further, the rigidity was 4250 MPa, which was superior to that of unreinforced polycarbonate. Moreover, as a result of conducting a weather resistance test of this sample, it was found that the weather resistance was superior to the molded product of Comparative Example 3. As a result of a 2000 hour exposure test in a sunshine weather meter exposure test (JIS B 7753-1993) with a black panel temperature of 63 ° C. and a method of irradiation and spraying of 120 minutes cycle (with rain), a molded article made of the composition of Comparative Example 3 While fine cracks were observed on the surface, no cracks were generated on the surfaces of the molded articles of the compositions of Examples 1 to 3.

In Example 2, a material having the same composition as that of Example 1 was molded with an open nozzle molding machine. However, when the suck back was set to 0 mm, a molded product having a good appearance was obtained as in Example 1. In Example 3, in addition to the composition used in Example 1, the composition described in Table 1 was used in order to improve flame retardancy. As a result, a molded article having a good appearance and further having flame retardancy (V-0 at 0.75 mm) could be produced.
In Example 4, molding was performed using an open nozzle, but a molded article having a good appearance was obtained when the volume increase rate of the measuring portion was 1%.
In Example 5, in addition to the flame retardant material, the electromagnetic wave was made of a material added with 30 parts of carbon filler in order to impart shielding properties, and the flame retardancy, conductivity, and electromagnetic wave shielding properties were measured. As a result, the flame resistance is V-0, the electrical conductivity is 0.4Ω with low surface efficiency, the electromagnetic wave shielding characteristics are 150mm x 150mm, and the thickness of 2mm test piece is based on MIL-STD-285 And measured in the frequency range 1-1000 MHz. As a result, at a frequency of 300 MHz, the electromagnetic wave shielding characteristic was 53 dB and a good result was obtained.
As Example 6 (not shown in Table 1), a composition in which coloring was used instead of the ultraviolet absorber from the components of Example 3 was molded. As the colorant, 0.001 part of “Mitsubishi Carbon # 50” and 2 parts of “Tioxide TR28” were used. As a result of molding using a shut-off nozzle, a molded product having a good gray appearance was obtained. The flame retardancy of the obtained molded product was V-0 at 0.75 mm.

In Comparative Example 1, since component C was not used, severe cis burst leaks were generated even when a shut-off nozzle was used, and only those having poor appearance characteristics could be produced.
Comparative Example 2 is a molding example using ordinary polycarbonate.
Comparative Example 3 is the result of molding a material having the same composition as in Example 4. However, when the suck back is 6 mm and the volume increase rate of the measuring part is 16%, silver streaks occur on the surface of the molded product. As a result, a molded product satisfying the appearance could not be obtained.
The thin molded article of the present invention was an aromatic polycarbonate resin molded article excellent in mechanical properties, melt stability and appearance.

  Examples of the thin molded article of the present invention are used for computer parts such as desktop personal computers and notebook personal computers, mobile phone parts, electrical / electronic devices, portable information terminals, home appliance parts, automobile interior parts, exterior parts, and the like. Furthermore, battery cases, plastic frames, and the like, which have been increasingly demanded for thin molded articles in recent years, and high appearance parts for automobiles can also be mentioned as suitable applications.

Claims (13)

  100 parts by mass of resin component (A) mainly composed of aromatic polycarbonate, 0.1 to 200 parts by mass of solid inorganic compound (B), organic acid, organic acid ester, organic acid anhydride, organic acid phosphonium salt, and organic acid ammonium When an aromatic polycarbonate resin composition containing 0.001 to 3 parts by mass of at least one compound (C) selected from the group consisting of salts is injection-molded, the molten resin is measured after the first injection step of the molten resin. And the method for producing an injection-molded article, wherein the process proceeds to the second injection step at a volume increase rate of 10% or less of the measuring section.   2. The method of manufacturing an injection-molded article according to claim 1, wherein the injection molding machine includes a nozzle for an injection molding machine used for the molding. The on-off valve is operated so that the pressure of the measured molten resin in the injection cylinder immediately before the opening of the on-off valve is 1 kgf / cm ² or more when the on-off valve is opened to shift to the injection process. The method for producing an injection-molded article according to claim 2.   The method for producing an injection-molded article according to claim 1, wherein the mold used for the injection molding has a hot runner.   The method for producing an injection-molded article according to claim 4, wherein the hot runner has a valve gate.   The aromatic polycarbonate resin composition is characterized by using an aromatic resin composition containing 0.001 to 1 part by mass of at least one organic acid metal salt selected from an organic acid alkali metal salt and an alkaline earth metal salt. The method for producing an injection-molded article according to claim 1.   The method for producing an injection-molded article according to claim 1, wherein the aromatic polycarbonate resin composition uses an aromatic resin composition containing 0.01 to 1 part by mass of a fluoropolymer.   The method for producing an injection-molded article according to claim 1, wherein the aromatic polycarbonate resin composition uses an aromatic resin composition containing a colorant.   The method for producing an injection-molded article according to claim 1, wherein the aromatic polycarbonate resin composition uses an aromatic resin composition containing an ultraviolet absorber.   The method for producing an injection-molded article according to claim 1, wherein the aromatic resin composition is an aromatic resin composition containing a conductive filler.   An injection-molded article characterized in that there is no appearance defect of silver streak or flow mark on the surface of the molded article by the method for producing an injection-molded article according to claim 1.   The injection molded body according to claim 11, wherein the injection molded body is a molded body for a housing.   The injection-molded article according to claim 11, wherein the injection-molded article is a molded article for automobiles or automobile parts.