JP2022143809A - Polycarbonate resin composition - Google Patents

Abstract

To provide a polycarbonate resin composition which can be improved in flowability while retaining optical properties and heat resistance.SOLUTION: The polycarbonate resin composition comprises: a polymer (A) comprising a constitutional unit (a1) derived from a compound represented by the formula (1) in the figure and a constitutional unit (a2) derived from methyl methacrylate, the polymer having a number-average molecular weight from 5000 to 30000; and a polycarbonate resin (B) comprising a structural unit derived from a specific dihydroxy compound.SELECTED DRAWING: None

Description

The present invention relates to a polycarbonate resin composition.

In recent years, the development of biomass-derived resins has been active toward the construction of a carbon recycling society, and the development of applications such as electrical equipment, electronic equipment, OA equipment, automobile parts, building parts, etc. is progressing. In order to expand into these applications, high optical properties (high transparency) for high color development, high heat resistance that does not deform due to the temperature of the usage environment, and high fluidity that facilitates processing into complex shapes are required. . Therefore, studies are also underway to meet the performance requirements for these applications by combining biomass-derived resins with other resin materials.

For example, Patent Document 1 contains a biomass-derived resin (A), a resin (B) incompatible with the resin (A), and a plasticizer (C), and the content of the resin (B) is higher than the resin (B). A resin composition is disclosed in which the content of (A) is greater and the glass transition temperature of resin (A) is higher than that of resin (B).

Japanese Patent Application Laid-Open No. 2020-37608

However, in the resin composition described in Patent Literature 1, the biomass-derived resin (A) and the resin (B) are not compatible with each other, so the optical properties and heat resistance are insufficient.

The present invention provides a polycarbonate resin composition that has improved fluidity and can maintain optical properties and heat resistance.

In order to solve the above problems, the present invention includes the following aspects.
[1] A polymer (A) having a structural unit (a1) derived from a compound represented by the following formula (1) and a structural unit (a2) derived from methyl methacrylate, and a polymer (A) represented by the following formula (2) The polymer (A ) has a number average molecular weight of 5,000 to 30,000.

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, or an alicyclic alkyl group having 1 to 10 carbon atoms.)

[2] The polycarbonate resin composition according to [1], wherein the ratio of the structural unit (a1) to the total of all structural units of the polymer (A) is 3 to 35% by mass.
[3] The polycarbonate resin composition according to [1] or [2], wherein the ratio of the structural unit (a1) to the total of all structural units of the polymer (A) is 3 to 25% by mass.
[4] The polycarbonate resin composition according to any one of [1] to [3], wherein the ratio of the structural unit (b1) to the total of all structural units of the polycarbonate resin (B) is 40 to 90% by mass. .
[5] The polycarbonate according to any one of [1] to [4], wherein the ratio of the polymer (A) to the total of the polymer (A) and the polycarbonate resin (B) is 1 to 50% by mass. Resin composition.
[6] The polycarbonate according to any one of [1] to [5], wherein the ratio of the polymer (A) to the total of the polymer (A) and the polycarbonate resin (B) is 1 to 30% by mass. Resin composition.

The polycarbonate resin composition of the present invention has improved fluidity by containing the polymer (A) having a specific structure. Moreover, since the polycarbonate resin composition of the present invention contains the polymer (A) having good compatibility with the polycarbonate resin (B), it can maintain optical properties and heat resistance.

[Explanation of terms]
The following term definitions apply throughout the specification and claims.
"Structural unit" means a structural unit derived from a monomer, that is, a structural unit formed by polymerizing a monomer, or a part of a structural unit is converted to another structure by treating a polymer. means a building block.
"Number average molecular weight" is the polymethyl methacrylate equivalent number average molecular weight measured by gel permeation chromatography.

[Polycarbonate resin composition]
A polycarbonate resin composition according to the present invention is a polycarbonate resin composition containing a polymer (A) and a polycarbonate resin (B). The polymer (A) comprises a structural unit (a1) derived from a compound represented by the following formula (1) (hereinafter also referred to as "compound (1)") and a structural unit (a2) derived from methyl methacrylate. It is a polymer having a number average molecular weight of 5,000 to 30,000. The polycarbonate resin (B) comprises a structural unit (b1) derived from a dihydroxy compound represented by the following formula (2) (hereinafter also referred to as "dihydroxy compound (2)") and a dihydroxy compound other than the dihydroxy compound (2). (hereinafter also referred to as "dihydroxy compound (3)") is a polycarbonate resin having a structural unit (b2) derived from.

However, in the above formula (1), R ¹ and R ² each independently represent a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, or an alicyclic alkyl group having 1 to 10 carbon atoms.

The polycarbonate resin composition may contain components other than the polymer (A) and the polycarbonate resin (B), if necessary.

In the polycarbonate resin composition, the ratio of polymer (A) to the total of polymer (A) and polycarbonate resin (B) is preferably 1 to 50% by mass. When the polymer (A) is 1% by mass or more, the polycarbonate resin composition has good optical properties. When the polymer (A) is 50% by mass or less, the polycarbonate resin composition has good fluidity. The lower limit of the proportion of polymer (A) is more preferably 5% by mass or more, and even more preferably 10% by mass or more. The upper limit of polymer (A) is more preferably 40% by mass or less, and even more preferably 30% by mass or less.

Each component will be described in detail below.
<Polymer (A)>
Polymer (A) has a structural unit (a1) derived from compound (1) and a structural unit (a2) derived from methyl methacrylate. The polymer (A) may have structural units (a3) derived from the compound (1) and methyl methacrylate or other monomers, if necessary.

The polymer (A) has a number average molecular weight of 5,000 to 30,000. When the polymer (A) has a number average molecular weight of 5,000 or more, a polycarbonate resin composition having excellent heat resistance can be obtained when blended with the polycarbonate resin (B). When the number average molecular weight of the polymer (A) is 30,000 or less, a polycarbonate resin composition having excellent fluidity and optical properties can be obtained. The lower limit of the number average molecular weight of the polymer (A) is preferably 7000 or more, more preferably 9000 or more. The upper limit of the number average molecular weight of the polymer (A) is preferably 27,000 or less, more preferably 24,000 or less.

(Constituent unit (a1))
Structural unit (a1) is a structural unit derived from compound (1). When the polymer (A) has the structural unit (a1), the compatibility between the polymer (A) and the polycarbonate resin (B) is improved. Accordingly, by blending the polymer (A) with the polycarbonate resin (B), a polycarbonate resin composition having excellent optical properties and heat resistance can be obtained. As the structural unit (a1), only one kind may be present, or two or more kinds may be present.

From the viewpoint of heat resistance of the resulting polycarbonate resin composition, R ¹ and R ² in the formula (1) are a hydrogen atom, a linear alkyl group having 1 to 5 carbon atoms, or an alicyclic ring having 1 to 5 carbon atoms. Alkyl groups are preferred, and methyl groups are more preferred. Structural unit (a1) is most preferably a structural unit derived from α-methylene-γ-butyrolactone, wherein R ¹ and R ² are hydrogen atoms in formula (1) above.

The ratio of the structural unit (a1) to the total of all structural units of the polymer (A) is preferably 3 to 35% by mass. When the ratio of the structural unit (a1) is 3% by mass or more, it becomes easier to obtain a polycarbonate resin composition having excellent optical properties. When the proportion of the structural unit (a1) is 35% by mass or less, it becomes easier to obtain a polycarbonate resin composition with excellent fluidity. More preferably, the proportion of the structural unit (a1) is 3 to 25% by mass.

(Constituent unit (a2))
The structural unit (a2) is a structural unit derived from methyl methacrylate. Since the polymer (A) has the structural unit (a2), a polycarbonate resin composition having excellent fluidity can be obtained when blended with the polycarbonate resin (B).

The ratio of the structural unit (a2) to the total of all structural units of the polymer (A) is preferably 60 to 95% by mass. When the ratio of the structural unit (a2) is 60% by mass or more, it becomes easier to obtain a polycarbonate resin composition having excellent fluidity. When the ratio of the structural unit (a2) is 95% by mass or less, it becomes easier to obtain a polycarbonate resin composition having excellent optical properties. The lower limit of the ratio of the structural unit (a2) is more preferably 65% by mass or more, and even more preferably 70% by mass or more. The upper limit of the proportion of the structural unit (a2) is more preferably 90% by mass or less, and even more preferably 85% by mass or less.

(Constituent unit (a3))
Structural unit (a3) is a structural unit derived from a monomer other than compound (1) and methyl methacrylate. As the structural unit (a3), only one type may be used, or two or more types may be present.

Other monomers include, for example, methacrylates other than methyl methacrylate such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, glycidyl Acrylates, phenyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, p-diphenyl acrylate, o-diphenyl acrylate, o-chlorophenyl acrylate, 4-methoxyphenyl acrylate, 4-chlorophenyl acrylate, 2,4,6-trichlorophenyl acrylate , 4-tert-butylphenyl acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; diene monomers such as butadiene, isoprene and dimethylbutadiene; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether Carboxylic acid vinyl monomers such as vinyl acetate and vinyl butyrate; Olefin monomers such as ethylene, propylene and isobutylene; Vinyl halide monomers such as vinyl chloride and vinylidene chloride; -Phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide and other maleimide monomers.

Other monomers may be cross-linking agents such as allyl (meth)acrylate, divinylbenzene, 1,3-butylene dimethacrylate and the like.
The other monomers are preferably methacrylate, acrylate, and vinyl cyanide monomers from the viewpoint of easy production of the polymer (A), and from the viewpoint of suppressing thermal decomposition of the polymer (A). , more preferably an acrylate.

The content of the structural unit (a3) with respect to the total of all structural units of the polymer (A) is preferably 10% by mass or less from the viewpoint of the heat resistance of the resulting polycarbonate resin composition.

Polymer (A) can be produced by polymerizing compound (1), methyl methacrylate, and optionally other monomers. The polymerization method includes known suspension polymerization method, solution polymerization method, emulsion polymerization method, bulk polymerization method and the like.

When the polymer (A) is produced by suspension polymerization, it is preferred to use a dispersant. This improves the dispersion stability of the polymer (A) in the solvent during polymerization. As the dispersant, surfactants, polyvinyl alcohol, polyethylene glycol, methacrylate polymers having ionic groups, and the like can be used. Examples of the methacrylate-based polymer having an ionic group include polymers containing structural units derived from sodium methacrylate, potassium methacrylate, sodium methacrylate sulfonate, sodium ethyl methacrylate sulfonate, and the like. A dispersing agent may be used individually by 1 type, and may use 2 or more types together.

<Polycarbonate resin (B)>
The polycarbonate resin (B) has a structural unit (b1) derived from the dihydroxy compound (2) and a structural unit (b2) derived from the dihydroxy compound (3) other than the dihydroxy compound (2).

(Constituent unit (b1))
The structural unit (b1) is a structural unit derived from the dihydroxy compound (2).
Examples of dihydroxy compounds (2) include biomass-derived isosorbide, isomannide, and isoidet. Among them, isosorbide is preferable from the viewpoint of excellent optical properties of the polycarbonate resin composition.

The ratio of the structural unit (b1) to the total of all structural units of the polycarbonate resin (B) is preferably 40 to 90% by mass. When the structural unit (b1) is 40% by mass or more, the polycarbonate resin composition has good heat resistance. When the structural unit (b1) is 90% by mass or less, the polycarbonate resin composition has good fluidity. The lower limit of the ratio of the structural unit (b1) is more preferably 45% by mass or more. Moreover, the upper limit of the structural unit (b1) is more preferably 85% by mass or less, and even more preferably 80% by mass or less.

(Constituent unit (b2))
The structural unit (b2) is a structural unit derived from the dihydroxy compound (3). As the structural unit (b2), only one type may be used, or two or more types may be present.
The dihydroxy compound (3) is preferably any one selected from the group consisting of aliphatic dihydroxy compounds, alicyclic dihydroxy compounds and aromatic dihydroxy compounds. In particular, from the viewpoint of excellent mechanical properties of the polycarbonate resin composition, alicyclic dihydroxy compounds are preferred, and specific examples include 1,4-cyclohexanedimethanol and tricyclodecanedimethanol.

The ratio of the structural unit (b2) to the total of all structural units of the polycarbonate resin (B) is preferably 10 to 60% by mass. When the structural unit (b2) is 10% by mass or more, the polycarbonate resin composition has good fluidity. When the structural unit (b2) is 60% by mass or less, the polycarbonate resin composition has good heat resistance. The lower limit of the ratio of the structural unit (b2) is more preferably 15% by mass or more, and even more preferably 20% by mass or more. More preferably, the upper limit of the ratio of the structural unit (b2) is 55% by mass or less.

The polycarbonate resin (B) can be obtained, for example, by polycondensing the dihydroxy compound (2), the dihydroxy compound (3), and optionally the carbonic acid diester as raw materials through a transesterification reaction.

Carbonic acid diesters include, for example, diphenyl carbonate, ditolyl carbonate, dimethyl carbonate, diethyl carbonate, di-t-butyl carbonate and the like. Among them, diphenyl carbonate is preferable from the viewpoint of excellent optical properties of the polycarbonate resin composition. Carbonic acid diesters may be used singly or in combination of two or more.

A commercially available product may be used as the polycarbonate resin (B). Commercially available products include, for example, Durabio D7340, Durabio D6350, Durabio D5380, and Durabio D5360 manufactured by Mitsubishi Chemical Corporation.

<Other ingredients>
The polycarbonate resin composition according to the present invention may contain other resins than the polymer (A) and the polycarbonate resin (B) within a range that does not impair the effects of the present invention.
If necessary, various additives (antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, etc.), various fillers (glass, mica, rubber particles, etc.) and the like may be included.

[Method for producing polycarbonate resin composition]
The polycarbonate resin composition according to the present invention can be produced by melt-kneading the polymer (A), the polycarbonate resin (B), and, if necessary, other components. Examples of melt-kneading devices include Banbury mixers, kneaders, rolls, kneader rolls, single-screw extruders, twin-screw extruders, and multi-screw extruders.
The polycarbonate resin composition according to the present invention may be molded into a desired shape depending on the application to obtain a molded product. As a molding method, a known method such as an injection molding method, an extrusion molding method, a compression molding method, or the like can be used.

EXAMPLES The present invention is illustrated below by way of examples. In the examples, the ratio of each structural unit of the polymer (A), how to determine the number average molecular weight, and how to evaluate the polycarbonate resin composition are as follows. "Parts" in the examples means "mass parts".

(percentage of constituent units)
The ratio of each structural unit in the polymer (A) and the polycarbonate resin composition was calculated from the charged amounts of the monomers.

(Number average molecular weight)
The number average molecular weight of polymer (A) was measured as follows. First, the elution curve of polymer (A) dissolved in tetrahydrofuran was measured by gel permeation chromatography using tetrahydrofuran as an eluent at a column temperature of 40°C. Then, the number average molecular weight of the polymer (A) was calculated based on the standard polymethyl methacrylate calibration curve.

(optical properties)
The optical properties of the polycarbonate resin composition were evaluated by total light transmittance and haze. High total light transmittance and low haze indicate good optical properties. The total light transmittance and haze were measured on a polycarbonate resin composition having a thickness of 2 mm according to JIS K 7136 using a haze meter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

(Liquidity)
The fluidity of the polycarbonate resin composition was evaluated by melt flow rate (MFR). High fluidity indicates good fluidity. MFR was measured on a pellet-shaped resin composition in accordance with JIS K-7210 under conditions of 230° C. and a load of 2.16 kgf.

(Heat-resistant)
The heat resistance of the polycarbonate resin composition was evaluated by the deflection temperature under load. A high deflection temperature under load indicates good heat resistance. Deflection temperature under load was measured in accordance with JIS K 7191-1 for a polycarbonate resin composition molded into a size of 80 mm long×10 mm wide×4 mm thick.

[Production Example 1]
(Production of polymer (A))
In a reaction vessel with a capacity of 1200 L equipped with a stirrer, a cooling pipe and a thermometer, 61.6 parts of a 17% by mass potassium hydroxide aqueous solution, Acryester M (Mitsubishi Chemical Co., Ltd. methyl methacrylate, trade name) 19.1 parts and 19.3 parts deionized water were added. The resulting mixture was stirred at room temperature, and after an exothermic peak was confirmed, the mixture was further stirred for 4 hours. After that, the mixed liquid was cooled to room temperature to obtain an aqueous potassium methacrylate solution.

Then, 900 parts of deionized water, 10 parts of the resulting potassium methacrylate aqueous solution, Acryester SEM-Na (Mitsubishi Chemical Co., Ltd. methacrylic 60 parts of acid 2-sulfoethyl sodium (trade name, 42% by mass aqueous solution) and 12 parts of Acryester M were added and stirred, and the temperature was raised to 50° C. while replacing the inside of the reaction vessel with nitrogen. Subsequently, 0.08 part of V-50 (2,2′-azobis(2-methylpropionamidine) dihydrochloride manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name) was added as a polymerization initiator, and 60 °C. After the temperature was raised, Acryester M was continuously added dropwise for 75 minutes at a rate of 0.24 parts/minute. The obtained solution was held at 60° C. for 6 hours and then cooled to room temperature to obtain a dispersant having a solid content of 10% by mass.

Subsequently, as described below, a polymer (A-1) having structural units (a1) derived from α-methylene-γ-butyrolactone and structural units (a2) derived from methyl methacrylate was produced. Table 1 shows the ratio of each structural unit to the total of all structural units of the polymer (A-1) and the number average molecular weight.

200 parts of deionized water, 0.26 parts of the dispersant obtained above, and 0.3 parts of sodium sulfate (Na ₂ SO ₄ ) were added into a polymerization apparatus equipped with a stirrer, condenser and thermometer. Stir to form a homogeneous aqueous solution.
Next, α-methylene-γ-butyrolactone (manufactured by Tokyo Kasei Co., Ltd.) 5 parts, Acryester M (Mitsubishi Chemical Co., Ltd., methyl methacrylate, trade name) 93 parts, methyl acrylate (Fujifilm Wako Pure Chemical Industries, Ltd. ), reagent special grade) 2 parts, and 2 parts of 1-octanethiol as a chain transfer agent (manufactured by Tokyo Chemical Industry Co., Ltd.), AMBN as a polymerization initiator (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2,2- 0.3 part of azobis-2-methylbutyronitrile (trade name) was added to prepare an aqueous dispersion. Next, the inside of the polymerization apparatus was sufficiently replaced with nitrogen, and the resulting aqueous dispersion was heated to 75° C. and held for 3 hours, then heated to 85° C. and held for 1.5 hours to carry out polymerization. rice field. After cooling to 40° C., an aqueous suspension containing polymer (A-1) was obtained. This aqueous suspension was filtered with a filter cloth, and the filtrate was washed with deionized water and dried at 75° C. for 18 hours to obtain polymer (A-1).

[Production Examples 2 to 4]
By the same method as in Production Example 1, polymers (A-2) to (A-4) having the structural unit (a1), the ratio of the structural unit (a2), and the molecular weights as shown in Table 1 were obtained. .

[Production Example 5]
By the same method as in Production Example 1, a polymer (X-1) having the structural unit (a1), structural unit (a2) ratio and molecular weight as shown in Table 1 was obtained.

[Example 1]
20 parts of the polymer (A-1) and 80 parts of Durabio D7340 (manufactured by Mitsubishi Chemical Corporation) containing 70% by mass of the structural unit (b1) as the polycarbonate resin (B) were placed in a polyethylene bag and hand-washed. Shake well and hand blend. The resulting mixture was melt-kneaded at 230° C. using a twin-screw extruder (TEM35B, manufactured by Toshiba Machine Co., Ltd.), extruded and then cut to obtain a resin composition in the form of pellets. Table 2 shows the results of evaluating the fluidity of the resin composition.
Next, the obtained pellet-shaped resin composition is molded at a molding temperature of 230 ° C. and a mold temperature of 80 ° C. using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., IS-100 molding machine). A resin composition molded into a shape corresponding to the above was obtained. Table 2 shows the results of evaluating the optical properties and heat resistance of the molded resin composition.

[Example 2]
A polycarbonate resin composition was obtained in the same manner as in Example 1, except that the polymer (A-1) was changed to the polymer (A-2). Table 2 shows the evaluation results of fluidity, optical properties and heat resistance of the polycarbonate resin composition.

[Example 3]
A polycarbonate resin composition was obtained in the same manner as in Example 1, except that the polymer (A-1) was changed to the polymer (A-3). Table 2 shows the evaluation results of fluidity, optical properties and heat resistance of the polycarbonate resin composition.

[Example 4]
A polycarbonate resin composition was obtained in the same manner as in Example 1, except that the polymer (A-1) was changed to the polymer (A-4). Table 2 shows the results of evaluating the fluidity, optical properties and heat resistance of the resin composition.

[Comparative Example 1]
A polycarbonate resin composition was obtained in the same manner as in Example 1, except that the polymer (A-1) was changed to the polymer (X-1). Table 2 shows the evaluation results of fluidity, optical properties and heat resistance of the polycarbonate resin composition.

[Comparative Example 2]
A polycarbonate resin composition was obtained in the same manner as in Example 1, except that the polymer (A-1) was changed to polylactic acid (Ingeo 3001D, manufactured by Nature Works). Table 2 shows the evaluation results of fluidity, optical properties and heat resistance of the polycarbonate resin composition.

[Reference example 1]
As the polycarbonate resin (B), only Durabio D7340 (manufactured by Mitsubishi Chemical Corporation) containing 70% by mass of the structural unit (b1) was used, and a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM35B) was used at 230 ° C. was melted and kneaded, and the extruded strand was cut to obtain pellets.
Using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., IS-100 molding machine), the obtained pellets are molded at a molding temperature of 230 ° C. and a mold temperature of 80 ° C., and a polycarbonate resin having a shape according to each evaluation. A composition was obtained. Table 2 shows the evaluation results of fluidity, optical properties and heat resistance of the polycarbonate resin composition.

As shown in Table 2, Examples 1 to 4, which are polycarbonate resin compositions containing predetermined polymer (A) and polycarbonate resin (B), are compared with Reference Example 1, which does not contain polymer (A). and improved liquidity. Further, these Examples 1 to 4 had good optical properties and heat resistance.

On the other hand, Comparative Example 1 using the polymer (X-1) not having the constituent element (a1) resulted in lower optical properties and heat resistance than Examples 1-4. Comparative Example 2, in which polylactic acid was used instead of the polymer (A), resulted in lower fluidity and optical properties than Examples 1-4.

INDUSTRIAL APPLICABILITY The resin composition of the present invention is useful for applications such as members of various devices (electrical devices, electronic devices, OA devices, etc.), automobile members (automobile headlamps, automobile interior materials, etc.), construction members, and the like.

Claims (6)

A polymer (A) having a structural unit (a1) derived from a compound represented by the following formula (1) and a structural unit (a2) derived from methyl methacrylate, and a dihydroxy compound represented by the following formula (2) A polycarbonate resin (B) having a structural unit (b1) derived from and a structural unit (b2) derived from a dihydroxy compound other than the dihydroxy compound represented by the following formula (2),
A polycarbonate resin composition, wherein the polymer (A) has a number average molecular weight of 5,000 to 30,000.

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, or an alicyclic alkyl group having 1 to 10 carbon atoms.)

2. The polycarbonate resin composition according to claim 1, wherein the ratio of said structural unit (a1) to the total of all structural units of said polymer (A) is 3 to 35% by mass. 3. The polycarbonate resin composition according to claim 1, wherein the ratio of said structural unit (a1) to the total of all structural units of said polymer (A) is 3 to 25% by mass. 4. The polycarbonate resin composition according to any one of claims 1 to 3, wherein the ratio of the structural unit (b1) to the total of all structural units of the polycarbonate resin (B) is 40 to 90% by mass. The polycarbonate resin composition according to any one of claims 1 to 4, wherein the ratio of the polymer (A) to the total of the polymer (A) and the polycarbonate resin (B) is 1 to 50% by mass. . The polycarbonate resin composition according to any one of claims 1 to 5, wherein the ratio of the polymer (A) to the total of the polymer (A) and the polycarbonate resin (B) is 1 to 30% by mass. .