WO2025225152A1 - Flame-retardant polycarbonate resin composition - Google Patents

Abstract

To provide a flame-retardant polycarbonate resin composition which does not generate toxic fumes at the time of combustion, passes regulations for PFAS and the like, has environmentally friendly advanced flame retardancy, and has excellent mechanical properties. The flame-retardant polycarbonate resin composition is characterized by comprising, with respect to 100 mass parts of a polycarbonate (A), 0.1-1.0 mass parts of halloysite (B), and 0.01-5 mass parts of a non-phosphorus-based or non-halogen-based flame retardant (C).

Description

Flame-retardant polycarbonate resin composition

The present invention relates to a flame-retardant polycarbonate resin composition, and more specifically, to a flame-retardant polycarbonate resin composition that meets PFAS regulations, is an environmentally friendly material, and yet possesses high levels of flame retardancy and excellent mechanical properties.

Polycarbonate resins have excellent heat resistance, mechanical properties, and electrical characteristics, and are widely used, for example, as materials for manufacturing vehicle parts, electrical and electronic equipment parts, housing components, and other industrial parts. In particular, flame-retardant polycarbonate resin compositions are ideally used in vehicle parts, electrical and electronic equipment parts such as personal computers, mobile phones, and battery cases, as well as parts for office equipment and information devices such as printers and copiers.

In recent years, the trend toward flame retardancy has grown, and high levels of flame retardancy are now required for polycarbonate resins, with many cases requiring V-0 products under the UL-94 testing method. Halogen-based flame retardants and phosphorus-based flame retardants have been used to impart flame retardancy to polycarbonate resins.
However, in order to achieve V-0 flame retardancy using phosphorus-based flame retardants, a relatively high addition rate is required, which tends to reduce the mechanical properties of polycarbonate resin materials. Flame retardancy using halogen-based bromine-based or chlorine-based flame retardants is now subject to stricter regulations due to toxicity and environmental concerns caused by the generation of harmful gases.

In particular, fluorine-based flame retardants, such as perfluoroalkane metal salts proposed in Patent Documents 1 and 2, can provide a high level of flame retardancy with a relatively small amount.
Furthermore, by blending such a flame retardant together with polyfluoroethylene as an anti-dripping agent, dripping can be suppressed and flame retardancy can be further improved.
However, in recent years, fluorine compounds have become subject to international restrictions, primarily in Japan, Europe, and the United States, and PFAS restrictions on perfluoroalkyl compounds and polyfluoroalkyl compounds are being implemented primarily in the EU and the United States, and polyfluoroethylene and the like are also subject to these restrictions. PFAS restrictions are becoming even more stringent internationally.

Special Publication No. 47-40445 Japanese Unexamined Patent Publication No. 49-88943

Therefore, there is a strong demand for a highly functional, environmentally friendly flame-retardant polycarbonate resin composition that does not generate toxic gases during combustion, meets various regulations such as the PFAS regulations, etc. However, it is not easy to achieve a V-0 rating in the UL-94 test without using a non-halogen flame retardant or a non-phosphorus flame retardant, or without further using polytetrafluoroethylene as a drip prevention agent.
The present invention has been made in view of the above circumstances, and an object (object) of the present invention is to provide a polycarbonate resin composition that complies with regulations such as PFAS and has high flame retardancy while being environmentally friendly.

As a result of extensive research conducted by the inventors in order to achieve the above-mentioned object, they discovered that the above-mentioned object can be achieved by including halloysite and a non-phosphorus or non-halogen flame retardant, and thus completed the present invention.
The present invention relates to the following flame-retardant polycarbonate resin composition and molded article.

1. A flame-retardant polycarbonate resin composition comprising, per 100 parts by mass of polycarbonate (A), 0.1 to 1.0 part by mass of halloysite (B) and 0.01 to 5 parts by mass of a non-phosphorus or non-halogen flame retardant (C).
2. The resin composition according to the above item 1, wherein the non-phosphorus or non-halogen flame retardant (C) is an organic sulfonic acid metal salt.
3. The resin composition according to any one of 1 and 2 above, further comprising 1 to 90 parts by mass of a filler (D) per 100 parts by mass of the polycarbonate resin (A).
4. The resin composition according to the above item 3, wherein the filler (D) is a glass-based filler.
5. The resin composition according to the above 4, wherein the glass-based filler is glass fiber.
6. The resin composition according to any one of 1 to 5 above, further comprising a mold release agent (E) in an amount of 0.1 to 2 parts by mass per 100 parts by mass of the polycarbonate resin (A).
7. The resin composition according to any one of 1 to 6 above, wherein UL-94 of a 1.5 mm thickness is V-0.
8. Pellets of the resin composition according to any one of 1 to 7 above.
9. A molded article made from the resin composition according to any one of 1 to 7 above.
10. A molded product of the pellets described in 8 above.

The flame-retardant polycarbonate resin composition of the present invention combines polycarbonate resin with halloysite and small amounts of a non-phosphorus or non-halogen flame retardant, resulting in no toxic gases being generated during combustion, complying with PFAS and other regulations, and possessing environmentally friendly high levels of flame retardancy and excellent mechanical strength.

The present invention will be described in detail below with reference to embodiments and examples.
In this specification, unless otherwise specified, the term "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.

The flame-retardant polycarbonate resin composition of the present invention is characterized by containing 0.1 to 1.0 parts by mass of halloysite (B) and 0.01 to 5 parts by mass of a non-phosphorus or non-halogen flame retardant (C) per 100 parts by mass of polycarbonate (A).

[Polycarbonate resin (A)]
The polycarbonate resin (A) used in the present invention is not particularly limited, and various types can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbon atoms directly bonded to the carbonate bonds are aromatic carbon atoms, and aliphatic polycarbonate resins in which the carbon atoms directly bonded to the carbonate bonds are aliphatic carbon atoms, and either type can be used. Among these, aromatic polycarbonate resins are preferred as the polycarbonate resin (A) from the viewpoints of heat resistance, mechanical properties, electrical properties, etc.

Among the monomers that are raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include:
Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene;
dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl;

Dihydroxynaphthalenes such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;

Dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;

2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A),
1,1-bis(4-hydroxyphenyl)propane,
2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C),
2,2-bis(3-methoxy-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane,
1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,
2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane,
α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
bis(4-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)cyclohexylmethane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)(4-propenylphenyl)methane,
bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
1,1-bis(4-hydroxyphenyl)-1-naphthylethan,
1,1-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)pentane,
1,1-bis(4-hydroxyphenyl)hexane,
2,2-bis(4-hydroxyphenyl)hexane,
1,1-bis(4-hydroxyphenyl)octane,
2,2-bis(4-hydroxyphenyl)octane,
4,4-bis(4-hydroxyphenyl)heptane,
2,2-bis(4-hydroxyphenyl)nonane,
1,1-bis(4-hydroxyphenyl)decane,
1,1-bis(4-hydroxyphenyl)dodecane,
Bis(hydroxyaryl)alkanes such as:

1,1-bis(4-hydroxyphenyl)cyclopentane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane,
1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane,
Bis(hydroxyaryl)cycloalkanes such as:

9,9-bis(4-hydroxyphenyl)fluorene,
Cardo structure-containing bisphenols such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

4,4'-dihydroxydiphenyl sulfide,
dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;
dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;
4,4'-dihydroxydiphenyl sulfone,
dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone;
etc.

Of these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred. In particular, from the viewpoints of impact resistance and heat resistance, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A) and 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C) are preferred.
The aromatic dihydroxy compounds may be used alone or in any combination of two or more in any ratio.

Among the monomers used as raw materials for polycarbonate resin, examples of carbonate precursors include carbonyl halides and carbonate esters. One type of carbonate precursor may be used, or two or more types may be used in any combination and ratio.

Specific examples of carbonyl halides include phosgene; and haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds.

Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

The method for producing polycarbonate resin (A) is not particularly limited, and any method can be used. Examples include interfacial polymerization, melt transesterification, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers. Of these, interfacial polymerization and melt transesterification are preferred because they are more effective in improving moist heat resistance, with interfacial polymerization being particularly preferred.

The molecular weight of the polycarbonate resin (A), expressed as a viscosity average molecular weight (Mv) calculated from the solution viscosity measured at 25° C. using methylene chloride as a solvent, is preferably 10,000 to 50,000, more preferably 11,000 to 40,000, and even more preferably 12,000 to 35,000, and particularly preferably 13,000 to 30,000. By setting the viscosity average molecular weight to at least the lower limit of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, and by setting the viscosity average molecular weight to at most the upper limit of the above range, the decrease in flowability of the polycarbonate resin composition of the present invention can be suppressed and improved, and molding processability can be enhanced, allowing for easier molding processability.
Two or more polycarbonate resins having different viscosity average molecular weights may be mixed together, and in this case, polycarbonate resins having viscosity average molecular weights outside the above-mentioned preferred range may be mixed.

The viscosity average molecular weight [Mv] refers to a value calculated from the Schnell viscosity formula, i.e., η = 1.23 × 10 ^-4 Mv ^0.83 , by measuring the intrinsic viscosity [η] (unit: dl/g) at 25°C using an Ubbelohde viscometer with methylene chloride as a solvent. The intrinsic viscosity [η] is also a value calculated from the specific viscosity [η _sp ] at each solution concentration [C] (g/dl) using the following formula:

Furthermore, in order to improve the appearance and flowability of molded articles, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1500 or more, preferably 2000 or more, and usually 9500 or less, preferably 9000 or less. Furthermore, the amount of polycarbonate oligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Furthermore, polycarbonate resin (A) may not only be made from virgin raw materials, but also from polycarbonate resin recycled from used products (so-called material-recycled polycarbonate resin). It is also preferable for it to contain both virgin polycarbonate resin and recycled polycarbonate resin, or it may consist entirely of recycled polycarbonate resin. When recycled polycarbonate resin is contained, the proportion of recycled polycarbonate resin in polycarbonate resin (A) is preferably 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more, and it is also preferable for it to be 100% recycled polycarbonate resin.

[Halloysite (B)]
Halloysite (B) is a type of clay mineral classified as a phyllosilicate mineral, and its chemical formula is Al ₂ Si ₂ O ₅ (OH) _4. Halloysite has a similar composition to kaolinite, but the bonds between unit layers are weaker, resulting in a layered structure with water molecules trapped between the layers, and a rolled, tubular morphology compared to the plate-like morphology commonly observed in kaolinite.

The mechanism by which halloysite exhibits flame retardancy is thought to be that when it is exposed to high heat such as a flame, interlayer water and structural water are released, which has a cooling and diluting effect, and the aluminol surface (-Al-OH ⁺ ) inside the halloysite becomes an acid site, which suppresses the formation of low molecular weight components due to the cleavage reaction of polycarbonate resin, making it easier for crosslinked structures to be formed due to isomerization reactions, and promoting good char formation.

The halloysite (B) is preferably surface-treated. Specific examples of the surface treatment agent include coupling agents such as silane coupling agents, titanate coupling agents, and aluminum coupling agents, alcohols such as trimethylolethane, trimethylolpropane, and pentaerythritol, alkanolamines such as triethylamine, organic silicone compounds such as organopolysiloxane, higher fatty acids such as stearic acid, fatty acid metal salts such as calcium stearate and magnesium stearate, polyacrylates such as sodium polyacrylate and ammonium polyacrylate, hydrocarbon lubricants such as polyethylene wax and liquid paraffin, basic amino acids such as lysine and arginine, polyglycerin, and derivatives thereof.
Among these, silane coupling agents are preferred, and particularly, silane coupling agents having a (meth)acrylic group, a vinyl group, an epoxy group, a thiol group, a benzotriazole group, or an ethylene carbonate structure are preferred, and (meth)acrylic silane coupling agents are particularly preferred, and those surface-treated with an acrylic silane having a (meth)acrylic group, especially a methacrylic group, as a functional group are preferred.

Halloysite is commercially available, and commercially available halloysite can also be used as halloysite (B).

The content of halloysite (B) is 0.1 to 1.0 parts by mass per 100 parts by mass of the polycarbonate resin (A), and good flame retardancy is achieved at such a low content. If the content is less than the lower limit, the flame retardancy is insufficient, and if the content is increased beyond the upper limit, decomposition of the polycarbonate proceeds, making it difficult to achieve good flame retardancy.
The content of halloysite (B) is preferably 0.11 parts by mass or more and preferably 0.9 parts by mass or less, and particularly preferably 0.8 parts by mass or less, 0.7 parts by mass or less, 0.6 parts by mass or less, 0.5 parts by mass or less, 0.4 parts by mass or less, 0.3 parts by mass or less, or 0.2 parts by mass or less, per 100 parts by mass of polycarbonate resin (A).
The average particle size of halloysite (B) is preferably 0.05 μm or more, more preferably 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, or 0.4 μm or more, and is also preferably 10 μm or less, and even more preferably 8 μm or less, 6 μm or less, 4 μm or less, or 2 μm or less, as a median particle size D50 of the particle size distribution measured by a laser scattering method (ISO13320:2009).

[Non-phosphorus or non-halogen flame retardant (C)]
The polycarbonate resin composition of the present invention contains a non-phosphorus and/or non-halogen flame retardant (C) that does not have a phosphorus atom or a halogen atom in its structural formula.
Examples of the non-phosphorus and/or non-halogen flame retardant (C) include silicone flame retardants made of silicone compounds, nitrogen-based flame retardants such as guanidine and melamine flame retardants, inorganic metal compounds, and silicate minerals other than halloysite (B), but fluorine-free organic sulfonic acid flame retardants are particularly preferred.

As the organic sulfonic acid flame retardant having no fluorine atoms, a non-fluorine organic sulfonic acid or a metal salt thereof having no C—F bond in the molecule is preferred.
The metal of the metal salt is preferably an alkali metal or alkaline earth metal, and examples thereof include alkali metals such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs); and alkaline earth metals such as magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). Of these, sodium, potassium, and cesium are preferred, with sodium and potassium being particularly preferred.

Preferred examples of fluorine-free organic sulfonic acids or metal salts thereof include aromatic sulfonic acids or metal salts thereof, aromatic sulfonamides (or sulfonimides) or metal salts thereof, and polystyrene sulfonic acid or metal salts thereof, with these metal salts being more preferred.

Specific examples of these include alkali metal salts of aromatic sulfonic acids having at least one aromatic group in the molecule, such as potassium 3-(phenylsulfonyl)benzenesulfonate (i.e., potassium diphenylsulfone-3-sulfonate), dipotassium diphenylsulfone-3,3'-disulfonate, sodium benzenesulfonate, potassium benzenesulfonate, cesium benzenesulfonate, sodium paratoluenesulfonate, potassium paratoluenesulfonate, cesium paratoluenesulfonate, sodium dodecylbenzenesulfonate, potassium dodecylbenzenesulfonate, cesium dodecylbenzenesulfonate, potassium styrenesulfonate, sodium polystyrenesulfonate, potassium polystyrenesulfonate, and cesium polystyrenesulfonate;
Examples include alkaline earth metal salts of aromatic sulfonic acids having at least one aromatic group in the molecule, such as magnesium paratoluenesulfonate, calcium paratoluenesulfonate, strontium paratoluenesulfonate, barium paratoluenesulfonate, magnesium dodecylbenzenesulfonate, and calcium dodecylbenzenesulfonate.

Examples of metal salts of aromatic sulfonamides (or sulfonimides) include potassium salts of N-(p-tolylsulfonyl)-p-toluenesulfonimide, potassium salts of N-(N'-benzylaminocarbonyl)sulfanilimide, and potassium salts of N-(phenylcarboxyl)-sulfanilimide.

Of the above-mentioned organic sulfonic acid flame retardants not containing fluorine atoms, paratoluenesulfonic acid or its metal salts, phenylsulfonylbenzenesulfonic acid or its metal salts, and polystyrenesulfonic acid or its metal salts are preferred, and among these, metal salts, particularly alkali metal salts, especially sodium salts or potassium salts are preferred.
The fluorine-free organic sulfonic acid flame retardants may be used alone or in any combination of two or more in any ratio.

The content of the non-phosphorus and/or non-halogen flame retardant (C) is 0.01 to 5 parts by mass, preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, 0.08 parts by mass or more, or even 0.10 parts by mass or more, per 100 parts by mass of the polycarbonate resin (A), and is preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, or even 1 part by mass or less.
When the non-phosphorus and/or non-halogen flame retardant (C) is an organic sulfonic acid flame retardant having no fluorine atoms, the content thereof is 0.01 to 5 parts by mass, more preferably 0.02 parts by mass or more, and among these, 0.03 parts by mass or more, 0.05 parts by mass or more, 0.06 parts by mass or more, 0.07 parts by mass or more, 0.08 parts by mass or more, 0.09 parts by mass or more, 0.10 parts by mass or more, and preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, and among these, 1 part by mass or less, 0.70 parts by mass or less, 0.50 parts by mass or less, 0.40 parts by mass or less, 0.30 parts by mass or less, 0.20 parts by mass or less is preferred. The mass ratio (C/B) of the content of the non-phosphorus and/or non-halogen flame retardant (C) to the content of the halloysite (B) is 0.3 or more and less than 1.5, preferably 0.5 or more and 0.6 or more, and preferably 1.45 or less, more preferably 1.4 or less, 1.35 or less, or 1.25 or less. By doing so, it is possible to obtain a polycarbonate resin composition that satisfies PFAS regulations and achieves V-0 flame retardancy with a small amount added.

The polycarbonate resin composition of the present invention is substantially free of phosphorus-based flame retardants and/or halogen-based flame retardants. Here, "substantially free" means that the amount of phosphorus-based flame retardants and/or halogen-based flame retardants, individually or in total, per 100 parts by mass of polycarbonate resin (A), is preferably less than 0.05 parts by mass, more preferably less than 0.03 parts by mass, even more preferably less than 0.01 parts by mass, less than 0.005 parts by mass, less than 0.001 parts by mass, and particularly preferably less than 0.0005 parts by mass.

[Filler (D)]
The polycarbonate resin composition of the present invention preferably further contains a filler (D). The filler (D) is preferably contained in an amount of 1 to 90 parts by mass per 100 parts by mass of the polycarbonate resin (A), together with the halloysite (B) and the non-phosphorus or non-halogen flame retardant (C), so that the flame retardancy provided by the halloysite (B) and the non-phosphorus or non-halogen flame retardant (C) and the dripping prevention ability provided by the filler (D) function in a well-balanced manner, thereby making it possible to achieve a higher level of flame retardancy.
The content of the filler (D) is more preferably 3 parts by mass or more, particularly 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, per 100 parts by mass of the polycarbonate resin (A), and is more preferably 80 parts by mass or less, particularly preferably 75 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.
The filler (D) may be contained in one kind or in two or more kinds.

The filler (D) is preferably an inorganic filler, and the inorganic filler may be any of an acicular inorganic filler, a fibrous inorganic filler, or a plate-like inorganic filler. Acicular inorganic fillers are inorganic fillers having a whisker-like or columnar shape, and examples thereof include wollastonite. Fibrous inorganic fillers refer to thin, long fibrous inorganic fillers, and examples thereof include glass fiber, ceramic fiber, and carbon fiber. Examples of the shape of fibrous inorganic fillers include chopped strands and milled fiber. Plate-like inorganic fillers are inorganic fillers having a flake-like or scaly shape, and examples thereof include talc, mica, and glass flakes.

The filler (D) is preferably a glass-based filler, and preferred examples thereof include glass fiber, glass flake, glass beads, and glass balloons, with glass fiber and glass flake being particularly preferred.
The raw glass composition is preferably alkali-free, and examples thereof include E-glass, C-glass, S-glass, and R-glass, with E-glass being preferred.

The cross-sectional shape of the glass fiber may be a typical perfect circle or various irregular cross-sectional shapes. The number average fiber length (cut length) of the glass fiber is preferably 0.5 to 10 mm, more preferably 1.0 to 5.0 mm. The number average fiber diameter of the glass fiber is preferably 4.0 μm or more, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more, with the upper limit being preferably 25.0 μm or less, more preferably 20 μm or less.
Glass fibers having a flat cross section are also preferred, with an aspect ratio of 1.5 to 8 being more preferred, and an aspect ratio of 2 to 6 being even more preferred.
The glass flakes may be, for example, scale-like flakes having a thickness of 0.5 to 20 μm and a side length of 0.05 to 1.0 mm.

It is also preferable that the glass-based filler be surface-treated with a surface treatment agent such as a silane coupling agent, such as gamma-methacryloxypropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, or gamma-aminopropyltriethoxysilane. The amount of surface treatment agent attached is preferably 0.01 to 1% by mass of the glass-based filler. Furthermore, if necessary, it is also possible to use fillers that have been surface-treated with lubricants such as fatty acid amide compounds and silicone oils, antistatic agents such as quaternary ammonium salts, film-forming resins such as epoxy resins and urethane resins, or mixtures of film-forming resins with heat stabilizers, flame retardants, etc.

[Release agent]
The resin composition of the present invention preferably contains a mold release agent.
Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

Aliphatic carboxylic acids include, for example, saturated or unsaturated aliphatic mono-, di-, or tri-carboxylic acids. Aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, with saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms being even more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralinic acid, montanic acid, adipic acid, and azelaic acid.

As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same aliphatic carboxylic acids as those described above can be used. On the other hand, as the alcohol, for example, saturated or unsaturated monohydric or polyhydric alcohols can be used. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or fewer carbon atoms are preferred, and saturated aliphatic monohydric alcohols or saturated aliphatic polyhydric alcohols having 30 or fewer carbon atoms are even more preferred. Note that the term aliphatic is used here to include alicyclic compounds as well.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

The above esters may contain aliphatic carboxylic acids and/or alcohols as impurities. Furthermore, the above esters may be pure substances, or may be mixtures of multiple compounds. Furthermore, the aliphatic carboxylic acids and alcohols that combine to form an ester may each be used alone, or two or more may be used in any combination and ratio.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

Examples of aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Aliphatic hydrocarbons also include alicyclic hydrocarbons. These hydrocarbons may be partially oxidized.
Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferred, and paraffin wax and polyethylene wax are more preferred.
The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.
The aliphatic hydrocarbon may be a single substance, but a mixture of substances with various constituent components and molecular weights can also be used as long as the main component is within the above range.

Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

The above-mentioned release agents may be contained in one type, or in two or more types in any combination and ratio.

The content of the release agent is preferably 0.1 to 2 parts by mass, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of polycarbonate resin (A). If the content of the release agent is below the lower limit of the above range, the release effect is likely to be insufficient, while if it exceeds the upper limit of the above range, there is a possibility that hydrolysis resistance will decrease and mold contamination will occur during injection molding.

[Stabilizer]
The polycarbonate resin composition of the present invention preferably contains a stabilizer, and the stabilizer is preferably a phosphorus-based stabilizer or a phenol-based stabilizer.

Any known phosphorus-based stabilizer can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2 metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, with organic phosphite compounds being particularly preferred.

Examples of the organic phosphite compound include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl/dinonyl phenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite.
Examples of such organic phosphite compounds include "ADK STAB 1178", "ADK STAB 2112", and "ADK STAB HP-10" manufactured by ADEKA CORPORATION, "JP-351", "JP-360", and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "IRGAFOS 168" manufactured by BASF.
The phosphorus-based stabilizer may be contained either alone or in any combination and ratio of two or more kinds.

The content of the phosphorus-based stabilizer is typically 0.001 part by mass or more, preferably 0.01 part by mass or more, and more preferably 0.03 part by mass or more, per 100 parts by mass of polycarbonate resin (A), and is typically 1 part by mass or less, preferably 0.7 part by mass or less, and more preferably 0.5 part by mass or less. If the content of the phosphorus-based stabilizer is below the lower limit of the above range, the thermal stabilization effect may be insufficient, while if the content of the phosphorus-based stabilizer exceeds the upper limit of the above range, the effect may plateau and the product may become uneconomical.

Examples of phenolic stabilizers include hindered phenolic antioxidants. Specific examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6- Examples of such hydroxybenzoates include 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like.

Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such phenolic antioxidants include "Irganox 1010" and "Irganox 1076" manufactured by BASF, and "Adekastab AO-50" and "Adekastab AO-60" manufactured by ADEKA.
The phenolic stabilizer may be contained alone or in any combination and ratio of two or more kinds.

The content of the phenolic stabilizer is typically 0.001 part by mass or more, preferably 0.01 part by mass or more, and typically 1 part by mass or less, preferably 0.5 part by mass or less, per 100 parts by mass of polycarbonate resin (A). By setting the content of the phenolic stabilizer at or above the lower limit of the above range, the effect as a phenolic stabilizer can be fully obtained, while by setting it at or below the upper limit of the above range, the effect does not plateau and is more economical.

[Additives, etc.]
The polycarbonate resin composition of the present invention may contain additives other than those described above, such as ultraviolet absorbers, fluorescent brighteners, pigments, dyes, plasticizers, compatibilizers, etc. These additives may be contained alone or in combination of two or more.

Furthermore, the polycarbonate resin (A) may contain other resins. Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate; styrene-based resins such as polystyrene resin, high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin.
When a resin other than the polycarbonate resin (A) is contained, the content thereof is preferably 45 parts by mass or less, and particularly preferably 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, and particularly preferably 1 part by mass or less, per 100 parts by mass of the polycarbonate resin (A).

[Polycarbonate resin composition]
The polycarbonate resin composition of the present invention has a high level of flame retardancy, and can achieve V-0 in a UL-94 test using a UL test piece having a thickness of 1.5 mm.
Furthermore, the polycarbonate resin composition of the present invention has excellent impact resistance, and can achieve an unnotched Charpy impact strength of 45 kJ/m ² or more, preferably 50 kJ/m ² or more, at a thickness of 4.0 mm.
The polycarbonate resin composition of the present invention also has excellent heat resistance, and its deflection temperature under load at a thickness of 4.0 mm and a load of 1.80 MPa is preferably 135°C or higher, more preferably 140°C or higher, even more preferably 141°C or higher, 143°C or higher, or 144°C or higher, and particularly preferably 145°C or higher.

The polycarbonate resin composition of the present invention can be molded into a molded article.
The manufacturing method of the molded article can be arbitrarily adopted molding method for polycarbonate resin composition.Examples thereof include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted hollow molding, molding using heat-insulating mold, molding using rapid heating mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding), extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc. Also, molding method using hot runner system can be used.Among them, injection molding methods such as injection molding, ultra-high speed injection molding, and injection compression molding are preferred.

[Molded product]
Examples of molded articles include parts for electric and electronic devices, office automation equipment, information terminal devices, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and sundries, lighting equipment, etc. Among these, the molded articles are suitable for use in parts for electric and electronic devices, office automation equipment, information terminal devices, home appliances, lighting equipment, etc., and are suitable for use in, for example, components for secondary battery devices used indoors or outdoors, battery packs, storage batteries for electric bicycles, etc., and components for housings used outdoors.

The present invention will be explained in more detail below by showing examples, but the present invention should not be construed as being limited to the following examples.
The components used in the examples and comparative examples are as shown in Table 1 below.

(Examples 1 to 10, Comparative Examples 1 to 5)
<Production of Resin Composition Pellets>
Of the above-mentioned components, all except filler (D) were blended in the proportions (parts by mass) shown in Table 2 below, mixed in a tumbler for 20 minutes, and then fed to a twin-screw extruder "TEX30α" equipped with one vent, manufactured by The Japan Steel Works, Ltd., and kneaded under conditions of a screw rotation speed of 200 rpm, a discharge rate of 25 kg/hr, and a barrel temperature of 280°C while further feeding filler (D) in the proportion (parts by mass) shown in Table 2 below from the middle of the barrel using a side feeder, and the molten resin extruded in the form of strands was quenched in a water tank and pelletized using a pelletizer to obtain pellets of a polycarbonate resin composition.

<Preparation of UL-94 test specimens>
The resin composition pellets obtained by the above-mentioned production method were dried at 120°C for 4 hours, and then injection molded using an SE100DU injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. under conditions of a cylinder temperature of 300°C, a mold temperature of 110°C, and a molding cycle of 40 seconds, to injection mold UL-94 test pieces having a length of 125 mm, a width of 13 mm, and a thickness of 1.5 mm.

<Flame retardancy rating: UL-94 (1.5 mmt)>
The UL test specimens obtained above were subjected to a test in accordance with the UL94 test (combustibility test for plastic materials for equipment parts) established by Underwriters Laboratories (UL) in the U.S. Flammability results were rated V-0, V-1, and V-2 in descending order of quality, with those that did not meet the standard being NR (not rated).

<Creating ISO multipurpose test specimens (4 mm)>
The resin composition pellets obtained above were dried at 120°C for 4 hours, and then injection molded using an injection molding machine (NEX80III type) manufactured by Nissei Plastic Industrial Co., Ltd. under the conditions of a cylinder setting temperature of 280°C, a mold temperature of 80°C, an injection time of 2 seconds, and a molding cycle of 50 seconds to injection mold an ISO multipurpose test piece (4 mm thick).

<Measurement of heat resistance (deflection temperature under load)>
The ISO dumbbell specimen (thickness: 4 mm) obtained above was used to measure the deflection temperature under load (DTUL, unit: ° C.) under a load of 1.80 MPa according to ISO 75 A method.

<Measurement of unnotched Charpy impact strength>
The ISO multipurpose test specimens (4 mmt) obtained by the above method were used to measure the unnotched Charpy impact strength (unit: kJ/m ² ) in accordance with ISO 179-1 and ISO 179-2. If the test specimen did not break in this measurement, it was recorded as NB (No Break).

<Measurement of flexural modulus>
The ISO multipurpose test piece (4 mmt) obtained by the above method was used to measure the flexural modulus (unit: GPa) in accordance with ISO178.

The evaluation results are shown in Table 2 below.
In the table, Actual n is Example n, and Relative n is Comparative Example n.

The polycarbonate resin composition of the present invention does not emit toxic gases when burned, meets PFAS and other regulations, exhibits excellent flame retardancy even with low additive amounts, and is a polycarbonate resin material with excellent mechanical properties, making it suitable for use in a variety of molded products.

Claims (10)

A flame-retardant polycarbonate resin composition comprising 100 parts by mass of polycarbonate (A), 0.1 to 1.0 parts by mass of halloysite (B), and 0.01 to 5 parts by mass of a non-phosphorus or non-halogen flame retardant (C). The resin composition according to claim 1, wherein the non-phosphorus or non-halogen flame retardant (C) is an organic sulfonic acid metal salt. The resin composition according to claim 1 or 2 further contains 1 to 90 parts by mass of filler (D) per 100 parts by mass of polycarbonate resin (A). The resin composition according to claim 3, wherein filler (D) is a glass-based filler. The resin composition according to claim 4, wherein the glass-based filler is glass fiber. The resin composition according to claim 1 or 2, further comprising 0.1 to 2 parts by mass of a release agent (E) per 100 parts by mass of the polycarbonate resin (A). The resin composition according to claim 1 or 2, whose UL-94 rating at a thickness of 1.5 mm is V-0. Pellets of the resin composition described in claim 1 or 2. A molded article made from the resin composition described in claim 1 or 2. A molded product made from the pellets described in claim 8.