JP7750641B2 - Polycarbonate-polydiorganosiloxane copolymer resin composition - Google Patents

Description

The present invention relates to a polycarbonate-polydiorganosiloxane copolymer resin composition that combines high flame retardancy with a high level of transparency.

Polycarbonate has excellent impact resistance and a high heat distortion temperature, making it suitable for many applications requiring strength and heat resistance (e.g., electrical and electronic equipment, automotive, etc.). The most widely produced polycarbonate is a homopolymer formed by polymerizing bisphenol A (BPA), but as its application fields expand, there is a demand for the development of polycarbonates with even better performance. Therefore, to accommodate these expanding applications, research has been conducted on copolymers by incorporating various copolymerizable monomer units into common monomer raw materials such as BPA. In particular, research on these copolymers has shown that polycarbonate-polydiorganosiloxane copolymers composed of BPA and a polydiorganosiloxane comonomer have superior flame retardancy and low-temperature impact resistance compared to homopolycarbonates polymerized with BPA (Patent Documents 1-3).

Patent Document 4 describes the use of vinyl-containing phenol-modified siloxanes as a method for further improving the flame retardancy of polycarbonate-polydiorganosiloxane copolymers. Patent Document 4 also notes that while polycarbonate-polydiorganosiloxane resin compositions have excellent flame retardancy, they are prone to developing cloudiness and other appearance defects under harsh molding conditions, such as high temperatures and extended residence times, when producing complex molded products.

Japanese Patent Application Publication No. 5-186675 Japanese Patent Application Publication No. 5-247195 WO1991/00885 publication Japanese Patent Application Laid-Open No. 2013-209546

The present invention was made in response to the problems of the conventional technology described above, and aims to provide a polycarbonate-polydiorganosiloxane copolymer resin composition that combines high flame retardancy with a high level of transparency.

As a result of extensive research conducted to achieve this objective, the inventors discovered that a resin composition containing a polycarbonate-polydiorganosiloxane copolymer with alkenyl group-containing polydiorganosiloxane blocks and a polycarbonate-polydiorganosiloxane copolymer with alkenyl group-free polydiorganosiloxane blocks exhibits extremely high flame retardancy and excellent transparency, leading to the present invention.

That is, the present invention is
1. A polycarbonate-polydiorganosiloxane copolymer resin composition containing a polycarbonate-polydiorganosiloxane copolymer (A) and a polycarbonate-polydiorganosiloxane copolymer (B) in a weight ratio of 99:1 to 1:99,
A polycarbonate-polydiorganosiloxane copolymer resin composition characterized in that the polycarbonate-polydiorganosiloxane copolymer (A) contains a polycarbonate block represented by the following general formula [1] and a polydiorganosiloxane block represented by the following general formula [3], and the polycarbonate-polydiorganosiloxane copolymer (B) does not contain a block represented by the following general formula [3] but contains a polycarbonate block represented by the following general formula [1] and a polydiorganosiloxane block represented by the following general formula [4].

[(In the above general formula [1], R ¹ and R ² each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group; when there are multiple of each, they may be the same or different; e and f each represent an integer of 1 to 4; and W is a single bond or at least one group selected from the group consisting of groups represented by the following general formula [2].)

(In the above general formula [2], R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ²⁰ each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group; when there are a plurality of 20, they may be the same or different; g is an integer from 1 to 10, and h is an integer from 4 to 7.

(In the above general formula [3], R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; at least one of R ³ , R ⁴ , R ⁷ and R ⁸ is an alkenyl group having 2 to 10 carbon atoms; R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p is a natural number; q is 0 or a natural number; and the average chain length (p+q) is a natural number from 1 to 150; and X is a divalent aliphatic group having 2 to 8 carbon atoms.)

(In the above general formula [4], R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p′ is a natural number from 1 to 150; and X is a divalent aliphatic group having 2 to 8 carbon atoms.)

2. The polycarbonate-polydiorganosiloxane copolymer resin composition according to 1 above, wherein the content of alkenyl groups in all of R ³ to R ⁸ in the general formula [3] is 1 to 60 mol %.
3. The polycarbonate-polydiorganosiloxane copolymer resin composition according to 1 or 2 above, wherein the number of repeating units of the siloxane containing an alkenyl group of the general formula [3] is 1 to 50.
4. The polycarbonate-polydiorganosiloxane copolymer resin composition according to any one of items 1 to 3 above, wherein the alkenyl group is a vinyl group.
5. The resin composition according to any one of 1 to 4 above, wherein the content of the alkenylsiloxane component in the resin composition is 0.01 to 3% by weight based on the total weight of the resin composition.
6. The polycarbonate-polydiorganosiloxane copolymer resin composition according to any one of 1 to 5 above, wherein the polycarbonate-polydiorganosiloxane copolymer (A) further contains a polydiorganosiloxane block represented by the general formula [4] above.
7. The resin composition according to any one of claims 1 to 6, wherein the total light transmittance (%) at a portion having a thickness of 2.0 mm is 60% or more.

The polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention combines high flame retardancy with a high level of transparency, and therefore offers exceptional industrial benefits.

The present invention is described in more detail below.

The polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention contains polycarbonate-polydiorganosiloxane copolymer (A) and polycarbonate-polydiorganosiloxane copolymer (B) in a weight ratio of 99:1 to 1:99.

(Polycarbonate-Polydiorganosiloxane Copolymer (A))
The polycarbonate-polydiorganosiloxane copolymer (A) of the present invention (hereinafter sometimes abbreviated as copolymer (A)) contains a polycarbonate block of formula [1] and a polydiorganosiloxane block of formula [3].
<Polycarbonate block of formula [1]>
The polycarbonate block is represented by the following formula [1].

[In the above formula [1], ^R1 and ^R2 each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group. When there are multiple ^R1s and multiple ^R2s , they may be the same or different.

Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, etc.

Examples of alkyl groups having 1 to 18 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and tetradecyl groups. Preferred are alkyl groups having 1 to 6 carbon atoms.

Examples of alkoxy groups having 1 to 18 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, and octoxy. Alkoxy groups having 1 to 6 carbon atoms are preferred.

Examples of cycloalkyl groups having 6 to 20 carbon atoms include cyclohexyl and cyclooctyl. Cycloalkyl groups having 6 to 12 carbon atoms are preferred.

Preferred examples of cycloalkoxy groups having 6 to 20 carbon atoms include cyclohexyloxy and cyclooctyloxy. Cycloalkyl groups having 6 to 12 carbon atoms are preferred.

Examples of alkenyl groups having 2 to 10 carbon atoms include methenyl, ethenyl, propenyl, butenyl, and pentenyl groups. Alkenyl groups having 1 to 6 carbon atoms are preferred.

Examples of aryl groups having 6 to 14 carbon atoms include phenyl and naphthyl groups. Examples of aryloxy groups having 6 to 14 carbon atoms include phenyloxy and naphthyloxy groups. Examples of aralkyl groups having 7 to 20 carbon atoms include benzyl and phenylethyl groups.

Examples of aralkyloxy groups having 7 to 20 carbon atoms include benzyloxy and phenylethyloxy groups.

Of these, hydrogen, methyl groups, and phenyl groups are particularly preferred.

e and f are each independently an integer from 1 to 4.

W is a single bond or at least one group selected from the group consisting of groups represented by the following formula [2]:

In formula [2], R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms.

Examples of alkyl groups having 1 to 18 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups. Alkyl groups having 1 to 6 carbon atoms are preferred.

Examples of aryl groups having 6 to 14 carbon atoms include phenyl and naphthyl groups. These may be substituted. Substituents include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, and butyl. Examples of aralkyl groups having 7 to 20 carbon atoms include benzyl and phenylethyl groups.

R ¹⁹ and R ²⁰ each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group. When there are multiple groups, they may be the same or different.

Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, etc.

Examples of alkyl groups having 1 to 18 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and tetradecyl groups. Preferred are alkyl groups having 1 to 6 carbon atoms.

Examples of alkoxy groups having 1 to 10 carbon atoms include methoxy, ethoxy, propoxy, butoxy, and pentoxy. Alkoxy groups having 1 to 6 carbon atoms are preferred.

Examples of cycloalkyl groups having 6 to 20 carbon atoms include cyclohexyl and cyclooctyl. Cycloalkyl groups having 6 to 12 carbon atoms are preferred.

Examples of cycloalkoxy groups having 6 to 20 carbon atoms include cyclohexyloxy and cyclooctyl. Cycloalkoxy groups having 6 to 12 carbon atoms are preferred.

Examples of alkenyl groups having 2 to 10 carbon atoms include methenyl, ethenyl, propenyl, butenyl, and pentenyl groups. Alkenyl groups having 1 to 6 carbon atoms are preferred.

Examples of aryl groups having 6 to 14 carbon atoms include phenyl and naphthyl groups.

Examples of aryloxy groups having 6 to 14 carbon atoms include phenyloxy and naphthyloxy groups.

Examples of aralkyl groups having 7 to 20 carbon atoms include benzyl and phenylethyl groups.

Examples of aralkyloxy groups having 7 to 20 carbon atoms include benzyloxy and phenylethyloxy groups.

g is an integer from 1 to 10, preferably an integer from 1 to 6, and more preferably an integer from 1 to 3. h is an integer from 4 to 7, preferably an integer from 4 to 5.

The polycarbonate block represented by formula [1] is a polycarbonate block containing 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4-biphenol, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3 ... Preferred are bis{2-(4-hydroxyphenyl)propyl}benzene and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, more preferred are 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4-biphenol, 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, and particularly preferred are blocks derived from 2,2-bis(4-hydroxyphenyl)propane.

The content of the polycarbonate block represented by formula [1] is preferably 50 to 99.9% by weight, more preferably 70 to 99.5% by weight, and even more preferably 80 to 99.0% by weight, based on the total weight of copolymer (A).

<Polydiorganosiloxane block of formula [3]>
It is represented by the following formula [3], which is derived from a hydroxyaryl-terminated polydiorganosiloxane.

In the above formula [3], R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and at least one of R ³ , R ⁴ , R ⁷ and R ⁸ is an alkenyl group having 2 to 10 carbon atoms.

Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups. Alkyl groups having 1 to 6 carbon atoms are preferred.

Examples of substituted or unsubstituted aryl groups having 6 to 12 carbon atoms include phenyl and naphthyl groups. Substituents include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups.

Examples of alkenyl groups having 2 to 10 carbon atoms include methenyl, ethenyl, propenyl, butenyl, and pentenyl groups. Alkenyl groups having 1 to 6 carbon atoms are preferred. It is particularly preferred that R ³ , R ⁴ , R ⁷ , and R ⁸ are methyl and ethenyl groups (commonly known as vinyl groups).

R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, etc.

Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups. Alkyl groups having 1 to 6 carbon atoms are preferred.

Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, a hexoxy group, a heptoxy group, and an octoxy group. An alkoxy group having 1 to 6 carbon atoms is preferred. It is particularly preferred that ^R9 and ^R10 are a hydrogen atom or a methoxy group.

X is a divalent aliphatic group having 2 to 8 carbon atoms. Examples of divalent aliphatic groups include alkylene groups having 2 to 8 carbon atoms. Examples of alkylene groups include ethylene, trimethylene, and tetramethylene.

p is a natural number, q is 0 or a natural number, and p+q is a natural number from 1 to 150. p+q is preferably from 3 to 120, more preferably from 5 to 100, and particularly preferably from 10 to 90.

The repeating units of p and q may be block or random.

The repeating unit of p may contain multiple units with different R ³ and R ^4. For example, as shown in the following formula [8], there may be repeating units of p1 and p2, in which case the sum of the repeating units of p1 and p2 is p, and the repeating units of p1 and p2 in this case may be block or random.

The repeating unit q may contain multiple units with different R ⁵ and R ^6. For example, as shown in the following formula [9], there may be repeating units q1 and q2, in which case the sum of the repeating units q1 and q2 is q, and the repeating units q1 and q2 in this case may be block or random.

To satisfy this specific chain length range, two or more different hydroxyaryl-terminated polydiorganosiloxane raw materials having an average chain length p + q may be mixed to prepare the polydiorganosiloxane raw materials. The polydiorganosiloxane raw materials may be mixed by mixing appropriate hydroxyaryl-terminated polydiorganosiloxane raw materials, or by pre-mixing polydiorganosiloxane precursors having an appropriate average chain length before hydroxyaryl-terminus modification, and then modifying the ends with hydroxyaryls.

The average chain length of the polydiorganosiloxane in copolymer (A) is 30 to 150, preferably 30 to 100, and more preferably 35 to 90. Within the above range, both impact resistance at low temperatures and productivity can be fully achieved.

The content of alkenyl groups in all R ³ to R ⁸ in the above formula [3] is 1 to 60 mol %, preferably 1 to 50 mol %, more preferably 4 to 50 mol %, even more preferably 4 to 25 mol %, and most preferably 8 to 25 mol %. For example, when R ³ is an alkenyl group, R ⁴ to R ⁸ are methyl groups, and p=12 and q=23, the content is 16.7 mol %, and when R ³ and R ⁴ are alkenyl groups, R ⁵ to R ⁸ are methyl groups, and p=12 and q=23, the content is 33.3 mol %.

If the alkenyl group content is below the lower limit, the anti-drip effect due to the crosslinking thickening of the alkenyl groups will be weaker and sufficient flame retardancy will not be achieved. On the other hand, if the alkenyl group content is above the upper limit, crosslinking will cause excessive aggregation of the siloxane, resulting in a deterioration of flame retardancy, which is undesirable.

The number p of alkenyl-containing siloxane repeating units in the above formula [3] is 1 to 80, preferably 1 to 60, more preferably 1 to 50, even more preferably 1 to 25, and most preferably 5 to 25.

The content of the alkenyl-containing siloxane repeating unit in the above formula [3] (hereinafter sometimes abbreviated as the alkenylsiloxane component content) is preferably 0.1 to 6 wt %, more preferably 0.1 to 5 wt %, even more preferably 0.15 to 4 wt %, and most preferably 0.15 to 3.5 wt %, based on the total weight of copolymer (A).

The content of polydiorganosiloxane blocks in copolymer (A) (hereinafter sometimes abbreviated as polydiorganosiloxane component content) is preferably 1 to 15% by weight, more preferably 2 to 14% by weight, and even more preferably 3 to 13% by weight, based on the total weight of copolymer (A).

The viscosity average molecular weight of copolymer (A) is preferably 13,000 to 25,000, more preferably 14,000 to 23,000. Copolymers with viscosity average molecular weights within this range are widely used in many fields because they provide practical mechanical strength.

Copolymer (A) can contain a polydiorganosiloxane block represented by the above general formula [4]. By including a polydiorganosiloxane block represented by the above general formula [4], excessive aggregation of the siloxane structure containing alkenyl groups is suppressed, resulting in higher flame retardancy and transparency.

(Polycarbonate-polydiorganosiloxane copolymer (B))
The polycarbonate-polydiorganosiloxane copolymer (B) of the present invention (hereinafter sometimes simply referred to as copolymer (B)) does not contain a block represented by the above general formula [3], but contains a polycarbonate block represented by formula [1] and a polydiorganosiloxane block represented by formula [4]. The polycarbonate block represented by formula [1] is the same as the polydiorganosiloxane copolymer (A) described above, except that the content of the polycarbonate block represented by formula [1] is preferably 50 to 99.9 wt %, more preferably 70 to 99.5 wt %, and even more preferably 80 to 99.0 wt %, based on the total weight of copolymer (B).

<Polydiorganosiloxane block of formula [4]>
It is represented by the following formula [4], which is derived from a hydroxyaryl-terminated polydiorganosiloxane.

In the above general formula [4], R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and are synonymous with R ⁵ , R ⁶ , R ⁷ and R ⁸ in the above formula [3], respectively, except that they do not contain an alkenyl group. It is particularly preferred that R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ are methyl groups.

^R21 and ^R22 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and are the same as ^R9 and ^R10 in the above formula [3], respectively. It is particularly preferable that ^R21 and ^R22 represent a hydrogen atom or a methoxy group.

X is a divalent aliphatic group having 2 to 8 carbon atoms and has the same meaning as in formula [3] above.

p' is a natural number from 1 to 150, preferably from 10 to 120, more preferably from 20 to 100, and particularly preferably from 30 to 90.

The repeating unit of p' may contain multiple units having different R ²³ and R ^24. For example, as shown in the following formula [10], there may be repeating units of p'1 and p'2, and in that case, the sum of the repeating units of p'1 and p'2 is p'.

To satisfy this specific chain length range, two or more different types of hydroxyaryl-terminated polydiorganosiloxane raw materials having an average chain length p' may be mixed to prepare the polydiorganosiloxane raw materials. The polydiorganosiloxane raw materials may be mixed by mixing appropriate hydroxyaryl-terminated polydiorganosiloxane raw materials together, or by pre-mixing polydiorganosiloxane precursors having an appropriate average chain length before the hydroxyaryl-terminated polydiorganosiloxane precursors are mixed together, and then the polydiorganosiloxane precursors are hydroxyaryl-terminated.

The average chain length of the polydiorganosiloxane in copolymer (B) is 30 to 150, preferably 30 to 100, and more preferably 35 to 90. Within the above range, both impact resistance at low temperatures and productivity can be fully achieved.

The content of the polydiorganosiloxane component in copolymer (B) is preferably 1 to 15% by weight, more preferably 2 to 14% by weight, and even more preferably 3 to 13% by weight, based on the total weight of copolymer (B).

The viscosity average molecular weight of copolymer (B) is preferably 13,000 to 25,000, more preferably 14,000 to 23,000. Copolymers with viscosity average molecular weights within this range are widely used because they provide practical mechanical strength in many fields.

(Polycarbonate-polydiorganosiloxane copolymer resin composition)
The polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention is not limited as long as it contains the polycarbonate-polydiorganosiloxane copolymer (A) and the polycarbonate-polydiorganosiloxane copolymer (B) in a weight ratio of 99:1 to 1:99, and may also contain at least one other resin. Preferably, (A)/(B) = 70 to 1/30 to 99 (wt%/wt%), and more preferably (A)/(B) = 50 to 1/50 to 99 (wt%/wt%). It is believed that the inclusion of copolymer (B) in the resin composition suppresses excessive aggregation of the alkenyl group-containing siloxane structure, thereby achieving transparency.

In polycarbonate-polydiorganosiloxane copolymer resin compositions, the average chain length of the polydiorganosiloxane is 30 to 150, preferably 30 to 100, and more preferably 35 to 90. Within the above range, both impact resistance at low temperatures and productivity can be fully achieved.

The polydiorganosiloxane component content of the polycarbonate-polydiorganosiloxane copolymer resin composition is preferably 1 to 15% by weight, more preferably 2 to 14% by weight, and even more preferably 3 to 13% by weight, based on the total weight of the resin composition.

The alkenylsiloxane component content in the polycarbonate-polydiorganosiloxane copolymer resin composition is 0.01 to 5% by weight, based on the total weight of the resin composition, preferably 0.01 to 3% by weight, more preferably 0.01 to 1.5% by weight, even more preferably 0.04 to 1.5% by weight, and most preferably 0.04 to 1.3% by weight. Within the above range, both impact resistance and transparency can be sufficiently achieved.

The viscosity average molecular weight of the polycarbonate-polydiorganosiloxane copolymer resin composition is preferably 13,000 to 25,000, and more preferably 14,000 to 23,000. Polycarbonate-polydiorganosiloxane copolymer resin compositions with a viscosity average molecular weight within this range are widely used in many fields because they provide practical mechanical strength.

In the UL94 vertical burning test, the polycarbonate-polydiorganosiloxane copolymer resin composition exhibits a total burning time of preferably 140 seconds or less at a thickness of 3.2 mm, more preferably 130 seconds or less, even more preferably 120 seconds or less, and particularly preferably 110 seconds or less.

The total light transmittance (%) of the polycarbonate-polydiorganosiloxane copolymer resin composition at a thickness of 2.0 mm is preferably 55% or more, more preferably 60% or more, even more preferably 70% or more, particularly preferably 75% or more, and most preferably 80% or more. Within the above range, extremely high transparency can be maintained.

In addition, the polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can be used in combination with other resin components as a third component, as described below, to the extent that the properties are not impaired.

<Other resin components>
The resin composition of the present invention may contain other resin components such as polyethylene, polyamide, polyacetal, polysulfone, polyarylate, ABS resin, phenolic resin, polyphenylene sulfide, polyether, polyimide, polyester, polyester carbonate, polycarbonate, etc., with polycarbonate being preferred. Specific polycarbonates are those composed of dihydric phenols that derive the formula [1] above, such as 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxy-3,3'-biphenyl)methane ... phenyl)propane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane , bis(4-hydroxyphenyl)diphenylmethane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-sulfonyldiphenol, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 2,2'4,4'-dimethyl-4,4'-sulfonyldiphenol,4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2'-diphenyl-4,4'-sulfonyldiphenol, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyldiphenyl sulfide, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene, and the like.

Among these, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-sulfonyldiphenol, 2,2'-dimethyl-4,4'-sulfonyldiphenol, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis{2-(4-hydroxyphenyl)propyl}benzene, and 1,4-bis{2-(4-hydroxyphenyl)propyl}benzene are preferred, and 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 4,4'-sulfonyldiphenol, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are particularly preferred. Of these, 2,2-bis(4-hydroxyphenyl)propane is the most suitable, as it has excellent strength and good durability. These may be used alone or in combination.

(Method for producing polycarbonate-polydiorganosiloxane copolymer)
The polycarbonate-polydiorganosiloxane copolymers (A) and (B) of the present invention can be produced by steps (i) and (ii).
Polycarbonate-polydiorganosiloxane copolymer (A)
<Step (i)>
Step (i) is a step of reacting a dihydric phenol represented by the following formula [5] with a carbonate ester-forming compound in a mixed solution of a water-insoluble organic solvent and an alkaline aqueous solution to prepare a solution containing a carbonate oligomer having a terminal chloroformate group.

(In the formula, R ¹ , R ² , e, f, and W are the same as defined above.)
As the dihydric phenol represented by the formula [5], the above-mentioned dihydric phenols from which polycarbonates are derived are preferably used.

<Step (ii)>
This step involves carrying out an interfacial polycondensation reaction between the carbonate oligomer of the dihydric phenol prepared in step (i) and a hydroxyaryl-terminated polydiorganosiloxane represented by the following formula [6] (which may include the following formula [7]), to obtain the polycarbonate-polydiorganosiloxane copolymer (A) of the present invention.

(In the formula, R ³ to R ¹⁰ , R ²¹ to R ²⁶ , X, p, q and p′ are the same as defined above.)

In step (i), a mixed solution containing an oligomer of dihydric phenol (I) having terminal chloroformate groups is obtained. While stirring the mixed solution, a hydroxyaryl-terminated polydiorganosiloxane (II) represented by general formula [5] is added at a rate of 0.004 molar equivalents/min or less relative to the amount of dihydric phenol (I) charged, and the hydroxyaryl-terminated polydiorganosiloxane (II) and the oligomer are subjected to interfacial polycondensation to obtain a polycarbonate-polydiorganosiloxane copolymer (A).

In the production of the present invention, the solvent may be any of a variety of reaction-inert solvents, such as those used in the production of known polycarbonates, and may be used alone or in combination. Typical examples include hydrocarbon solvents such as xylene, and halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. Halogenated hydrocarbon solvents such as methylene chloride are particularly preferred. The concentration of the dihydric phenol (I) is preferably 500 g/L or less, more preferably 450 g/L or less, and even more preferably 300 g/L or less. From the standpoint of production efficiency, the lower limit of the dihydric phenol (I) concentration is preferably 150 g/L or more.

During the interfacial polycondensation reaction, an acid binder may be added as needed, taking into account the stoichiometric ratio (equivalents) of the reaction. Examples of acid binders that can be used include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, organic bases such as pyridine, and mixtures of these. Specifically, when the hydroxyaryl-terminated polydiorganosiloxane that derives formula [3] or formula [4] above, or a portion of the dihydric phenol as described above, is added as an additional monomer to this reaction stage, it is preferable to use 2 equivalents or more of alkali relative to the total number of moles of the subsequently added dihydric phenol and hydroxyaryl-terminated polydiorganosiloxane (usually 1 mole corresponds to 2 equivalents).

The interfacial polycondensation reaction between the dihydric phenol oligomer and the hydroxyaryl-terminated polydiorganosiloxane is carried out by vigorously stirring the mixture.

In such polymerization reactions, a terminal terminator or molecular weight regulator is typically used. Examples of terminal terminators include compounds with a monovalent phenolic hydroxyl group, such as ordinary phenol, p-tert-butylphenol, p-cumylphenol, and tribromophenol, as well as long-chain alkylphenols, aliphatic carboxylic acid chlorides, aliphatic carboxylic acids, hydroxybenzoic acid alkyl esters, hydroxyphenyl alkyl acid esters, and alkyl ether phenols. The amount used is in the range of 100 to 0.5 mol, preferably 50 to 2 mol, per 100 mol of all dihydric phenol compounds used; it is of course also possible to use two or more compounds in combination.

To accelerate the polycondensation reaction, a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt may be added.
The reaction time for this polymerization reaction must be relatively long to reduce the amount of unreacted polydiorganosiloxane components, preferably 30 minutes or more, more preferably 50 minutes or more. On the other hand, since stirring the reaction solution for a long period of time can cause polymer precipitation, the reaction time is preferably 180 minutes or less, more preferably 90 minutes or less.

The reaction pressure can be reduced, normal, or increased, but is usually preferably normal pressure or the natural pressure of the reaction system.

The reaction temperature is selected from the range of -20 to 50°C, and in many cases, water or ice cooling is desirable as heat is generated during polymerization.

If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added.
Polycarbonate-polydiorganosiloxane copolymer (B)
Polycarbonate-polydiorganosiloxane copolymer (B) was prepared in the same manner as in the preparation of polycarbonate-polydiorganosiloxane copolymer (A), except that in step ii) of the preparation of polycarbonate-polydiorganosiloxane copolymer (A), a hydroxyaryl-terminated polydiorganosiloxane represented by the above formula [7] was used as the polydiorganosiloxane instead of the hydroxyaryl-terminated polydiorganosiloxane represented by the above formula [6].

(Method for producing polycarbonate-polydiorganosiloxane copolymer resin composition)
The polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can contain various flame retardants, reinforcing fillers, and additives that are usually added to polycarbonate resins, provided that the effects of the present invention are not impaired.

In the present invention, the polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can be pelletized by melt-kneading using an extruder such as a single-screw extruder or a twin-screw extruder. When producing such pellets, the various flame retardants, reinforcing fillers, and additives described above can also be blended.

Flame retardants include various compounds conventionally known as flame retardants for thermoplastic resins, particularly aromatic polycarbonate resins. However, more preferred are organometallic salt-based flame retardants (e.g., organic alkali (earth) metal sulfonates, metal borate-based flame retardants, and metal stannate-based flame retardants), organophosphorus-based flame retardants (e.g., monophosphate compounds, phosphate oligomer compounds, phosphonate oligomer compounds, phosphonitrile oligomer compounds, phosphonic acid amide compounds, and phosphazenes), silicone-based flame retardants made from silicone compounds, and fibrillated PTFE. Among these, organometallic salt-based flame retardants and organophosphorus-based flame retardants are particularly preferred. The incorporation of such compounds not only improves flame retardancy, but also, depending on the properties of each compound, improves antistatic properties, fluidity, rigidity, and thermal stability, among other things.

In the present invention, the polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can be used to produce various products by injection molding pellets produced as described above. Furthermore, it is also possible to directly form sheets, films, profile extrusion molded products, direct blow molded products, and injection molded products from the resin melt-kneaded in an extruder without first going through the pellet process.

In such injection molding, molded products can be obtained using not only conventional molding methods, but also injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, insulated mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high-speed injection molding, depending on the purpose. The advantages of these various molding methods are already widely known. Furthermore, molding can be done using either the cold runner method or the hot runner method.

In addition, in the present invention, the polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can be used in the form of various profile extrusion molded products, sheets, films, etc. by extrusion molding. Sheets and films can also be molded using methods such as inflation, calendaring, and casting. Furthermore, by subjecting the composition to a specific stretching operation, it can also be molded into heat-shrinkable tubing. The polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can also be molded into molded products by rotational molding, blow molding, etc.

Furthermore, in the present invention, molded articles made from the polycarbonate-polydiorganosiloxane copolymer resin composition of the present invention can be subjected to various surface treatments. Surface treatments referred to here involve forming a new layer on the surface of a resin molded article, such as vapor deposition (physical vapor deposition, chemical vapor deposition, etc.), plating (electroplating, electroless plating, hot-dip plating, etc.), painting, coating, or printing, and methods commonly used for polycarbonate resins can be applied. Specific examples of surface treatments include hard coating, water-repellent/oil-repellent coating, ultraviolet-absorbing coating, infrared-absorbing coating, and metallizing (vapor deposition, etc.).

The present invention will be explained in more detail below with reference to examples, but these examples are not intended to limit the scope of the present invention. Unless otherwise specified, parts in the examples are parts by weight and percentages are percentages by weight. Evaluations were performed according to the following methods.

(1) Viscosity average molecular weight (Mv)
The specific viscosity (ηSP) calculated by the following formula was determined using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20°C.
Specific viscosity (η _SP )=(t−t ₀ )/t ₀
[ _t0 is the number of seconds for methylene chloride to fall, and t is the number of seconds for the sample solution to fall]
The viscosity average molecular weight Mv is calculated from the determined specific viscosity (ηSP) using the following formula.
η _SP /c = [η] + 0.45 × [η] ² c (where [η] is the intrinsic viscosity)
[η]=1.23×10 ⁻⁴ Mv ^0.83
c=0.7

(2) Polydiorganosiloxane Component Content, Alkenylsiloxane Component Content, and Polydiorganosiloxane Repeating Number Using a JNM-AL400 manufactured by JEOL Ltd., the 1H-NMR spectra of the obtained polycarbonate-polydiorganosiloxane copolymer and the resin composition containing it were measured, and the content of each component was calculated from the integral ratio calculated from the integral curve of the peak (1.4 to 1.8 ppm) derived from the dihydric phenol (bisphenol A), the integral curve of the peak (-0.2 to 0.3 ppm) derived from the polydiorganosiloxane, and the integral curve of the peak derived from the alkenylsiloxane (5.6 to 6.1 ppm in the case of a vinyl group).
Similarly, the repeat number of the polydiorganosiloxane was calculated by comparing the integral ratio calculated from the integral curve of the peaks (0.4 to 0.6 ppm and 2.5 to 2.7 ppm) derived from the hydroxyaryl terminal and the integral curve of the peak derived from the polydiorganosiloxane.

(3) Flame retardancy: A vertical flame test (UL94V) was conducted according to the method (UL94) specified by Underwriters Laboratories, Inc., USA.
(a) 3.2mm total burning time in seconds and (b) 3.2mm flame retardancy class: Evaluation was performed by conducting a vertical burning test with a test piece 3.2mm thick. Five samples were flamed a total of 10 times, and the total burning time in seconds was recorded. Those that did not fall into any of the V-0, V-1, or V-2 categories were recorded as "not-V."

(4) Total Light Transmittance The pellets were retained for 10 minutes at a cylinder temperature of 350°C to form a three-tiered plate having a width of 50 mm, a length of 90 mm, and thicknesses of 3.0 mm (length 20 mm), 2.0 mm (length 45 mm), and 1.0 mm (length 25 mm) from the gate side. The total light transmittance (%) at the 2.0 mm thick portion was measured using a Haze Meter NDH 2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with ASTM D1003.

[Hydroxyaryl-Terminated Polydiorganosiloxane]
In the examples and comparative examples, a polydiorganosiloxane compound having the following structure was used.

[Production of Polycarbonate-Polydiorganosiloxane Copolymer (A)]
(Production Example 1)
A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 17,590 parts of ion-exchanged water and 6,883 parts of a 25% aqueous sodium hydroxide solution, and 3,748 parts (16.41 moles) of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) as the dihydric phenol (I) represented by the general formula [1] above, and 7.5 parts of hydrosulfite were dissolved therein. Then, 14,060 parts of methylene chloride (10 molar equivalents relative to the dihydric phenol (I)) was added, and 1,900 parts of phosgene was blown in over 70 minutes at 16 to 24° C. with stirring. A solution of 1,324 parts of a 25% aqueous sodium hydroxide solution and 107 parts of p-tert-butylphenol dissolved in 8,000 parts of methylene chloride was added, and a solution of 444 parts (0.142 moles) of PMVS-1 dissolved in 800 parts of methylene chloride was added with stirring to form an emulsion, followed by vigorous stirring again. With stirring, 4.2 parts of triethylamine was added while the reaction mixture was at 26°C, and stirring was continued for 1 hour at a temperature of 26-31°C to terminate the reaction. After the reaction was completed, the organic phase was separated, diluted with methylene chloride, and repeatedly washed with water. When the washings became neutral, the organic phase was washed with acidic hydrochloric acid water. The mixture was then repeatedly washed with ion-exchanged water until the conductivity of the aqueous phase became nearly the same as that of the ion-exchanged water. The mixture was then placed in a kneader filled with warm water, and the methylene chloride was evaporated while stirring to obtain a polycarbonate-polydiorganosiloxane copolymer powder. After dehydration, the mixture was dried for 12 hours at 120°C in a hot air circulating dryer. The resulting polycarbonate-polydiorganosiloxane copolymer (PMVS-PC-1) had a viscosity average molecular weight of 19,600, a polydiorganosiloxane component content of 8.4 wt%, and an alkenylsiloxane component content of 3.0 wt%.

(Production Example 2)
The same production method as for PMVS-PC-1 was used, except that PMVS-1 was changed to 434 parts (0.142 moles) of PMVS-2. The resulting polycarbonate-polydiorganosiloxane copolymer (PMVS-PC-2) had a viscosity average molecular weight of 19,500, a polydiorganosiloxane component content of 8.4 wt%, and an alkenylsiloxane component content of 1.5 wt%.

(Production Example 3)
The same production method as for PMVS-PC-1 was used, except that PMVS-1 was changed to 425 parts (0.142 moles) of PMVS-3. The resulting polycarbonate-polydiorganosiloxane copolymer (PMVS-PC-3) had a viscosity average molecular weight of 19,300, a polydiorganosiloxane component content of 8.3 wt%, and an alkenylsiloxane component content of 0.2 wt%.

(Production Example 4)
The same production method as for PMVS-PC-1 was used, except that PMVS-1 was changed to 541 parts (0.142 moles) of PMVS-4. The resulting polycarbonate-polydiorganosiloxane copolymer (PMVS-PC-4) had a viscosity average molecular weight of 19,200, a polydiorganosiloxane component content of 9.5 wt%, and an alkenylsiloxane component content of 3.2 wt%.

(Production Example 5)
The same production method as for PMVS-PC-1 was used, except that 444 parts (0.142 mol) of PMVS-1 was replaced by 222 parts (0.071 mol) of PMVS-1 and 208 parts (0.071 mol) of PDMS. The resulting polycarbonate-polydiorganosiloxane copolymer (PMVS-PC-5) had a viscosity average molecular weight of 19,500, a polydiorganosiloxane component content of 8.4 wt%, and an alkenylsiloxane component content of 1.5 wt%.

[Production of Polycarbonate-Polydiorganosiloxane Copolymer (B)]
(Production Example 6)
The same production method as for PMVS-PC-1 was used, except that PMVS-1 was not used and 415 parts (0.142 mol) of PDMS was used instead. The viscosity average molecular weight of the resulting polycarbonate-polydiorganosiloxane copolymer (PDMS-PC) was 19,500, and the polydiorganosiloxane content was 8.3 wt%.

(PC)
A linear aromatic polycarbonate resin powder (Panlite L-1225WX, manufactured by Teijin Limited) having a solution viscosity of 19,700 and a molecular weight of 19,700, which has a repeating skeleton of 2,2-bis(4-hydroxyphenyl)propane.

The above results are shown in Table 1.

(Examples 1 to 8, Comparative Examples 1 to 4)
PMVS-PC-1 to 5 obtained by the above production method, PDMS-PC, and PC were mixed with 300 ppm of tris(2,4-di-tert-butylphenyl)phosphite (BASF Corporation: Irgafos 168) in the blending ratios shown in the table below, and then melt-kneaded using a vented twin-screw extruder (Technovel Corporation, KZW15-25MG) to obtain pellets. The extrusion conditions were a discharge rate of 2.5 kg/h, a screw rotation speed of 200 rpm, and an extrusion temperature of 280°C from the first feed port to the die. The obtained pellets were used in an injection molding machine (Japan Steel Works, Ltd., JSW J-75EIII) to prepare 3.2 mm UL test specimens and 2 mm molded specimens that were retained for 10 minutes at a cylinder temperature of 350°C, and various evaluations were performed. The evaluation results are shown in Table 2.

The polycarbonate-polydiorganosiloxane copolymer of the present invention is recognized to combine high flame retardancy with a high degree of transparency.

The polycarbonate-polydiorganosiloxane copolymer of the present invention combines high flame retardancy with a high level of transparency, making it suitable for a wide range of uses in optical components, electrical and electronic equipment, and the automotive industry. It is particularly useful for various housing molded products that are expected to be exposed to harsh environments such as cold climates and high-temperature heat treatment.

Claims (6)

A polycarbonate-polydiorganosiloxane copolymer resin composition containing a polycarbonate-polydiorganosiloxane copolymer (A) and a polycarbonate-polydiorganosiloxane copolymer (B) in a ratio (A)/(B) of 70 to 1/30 to 99 (wt %/wt %),
A polycarbonate-polydiorganosiloxane copolymer resin composition characterized in that the polycarbonate-polydiorganosiloxane copolymer (A) contains a polycarbonate block represented by the following general formula [1] and a polydiorganosiloxane block represented by the following general formula [3], and the polycarbonate-polydiorganosiloxane copolymer (B) does not contain a block represented by the following general formula [3] but contains a polycarbonate block represented by the following general formula [1] and a polydiorganosiloxane block represented by the following general formula [4], and the content of the alkenylsiloxane component in the resin composition is 0.04 to 1.3 wt % based on the total weight of the resin composition.
[(In the above general formula [1], R ¹ and R ² each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group; when there are multiple of each, they may be the same or different; e and f each represent an integer of 1 to 4; and W is a single bond or at least one group selected from the group consisting of groups represented by the following general formula [2].)
(In the above general formula [2], R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms and an aralkyl group having 7 to 20 carbon atoms; R ¹⁹ and R ²⁰ each independently represent a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group; when there are a plurality of 20, they may be the same or different; g is an integer from 1 to 10, and h is an integer from 4 to 7.
(In the above general formula [3], R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms , a substituted or unsubstituted aryl group having 6 to 12 carbon atoms , or an alkenyl group having 2 to 10 carbon atoms ; at least one of R ³ , R ⁴ , R ⁷ and R ⁸ is an alkenyl group having 2 to 10 carbon atoms; R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p is a natural number; q is 0 or a natural number; and the average chain length (p+q) is a natural number from 1 to 150; and X is a divalent aliphatic group having 2 to 8 carbon atoms.)
(In the above general formula [4], R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; p′ is a natural number from 1 to 150; and X is a divalent aliphatic group having 2 to 8 carbon atoms.) 2. The polycarbonate-polydiorganosiloxane copolymer resin composition according to claim 1, wherein the content of alkenyl groups in all of R ³ to R ⁸ in the general formula [3] is 1 to 60 mol %. The polycarbonate-polydiorganosiloxane copolymer resin composition according to claim 1 or 2, wherein the number of repeating siloxane units containing an alkenyl group of general formula [3] is 1 to 50. The polycarbonate-polydiorganosiloxane copolymer resin composition according to any one of claims 1 to 3, characterized in that the alkenyl group is a vinyl group. The polycarbonate-polydiorganosiloxane copolymer resin composition according to any one of claims 1 to 4, wherein the polycarbonate-polydiorganosiloxane copolymer (A) further contains a polydiorganosiloxane block represented by the above general formula [4]. The resin composition according to any one of claims 1 to 5, wherein the total light transmittance (%) at a thickness of 2.0 mm is 60% or more.