JP7752671B2 - Polycarbonate-polysiloxane resin - Google Patents

Description

The present invention relates to polycarbonate-polysiloxane resins.

In recent years, in the mobility sector, there has been a demand for reducing vehicle weight in order to reduce environmental impact and improve driving range, and the use of resin for components is being considered. Furthermore, in recent years, the area occupied by resin components has tended to expand, creating a demand for resin materials with low specific gravity. In particular, resin glazing, which replaces glass, uses polycarbonate resin, which has excellent transparency, heat resistance, and impact resistance. Compared to glass, resin glazing has a lower specific gravity, and by selecting processing methods such as injection molding, it offers a high degree of freedom in shape and allows for the integration of multiple components, which is expected to lead to lighter vehicle bodies and improvements in design and productivity.

In order to further reduce the weight of vehicle bodies, there is a growing demand for polycarbonate resins with even lower specific gravity while maintaining the excellent properties of conventional polycarbonate resins.

Patent Document 1 discusses polycarbonate resins with specific structural units. However, they have the problem of insufficient impact resistance at low temperatures, and do not exhibit sufficient impact resistance, particularly in cold regions such as high latitudes and mountainous areas.

International Publication No. 2019/009076

The object of the present invention is to provide a polycarbonate-polysiloxane resin that is excellent in transparency, impact resistance, heat resistance, moldability, and pencil hardness, while also having a low specific gravity.

As a result of extensive research, the present inventors have found that a polycarbonate-polysiloxane resin containing a polycarbonate block and a polysiloxane block, each containing a specific structural unit, is excellent in transparency, impact resistance, heat resistance, moldability, and pencil hardness, and also has a low specific gravity, thereby completing the present invention.
That is, according to the present invention, the object of the invention is achieved as follows.

1. A polycarbonate-polysiloxane resin comprising a polycarbonate block (A-1) and a polysiloxane block (A-2), characterized in that the specific gravity of the resin is 1.10 or less and the glass transition temperature of the resin is 100 to 190°C.

2. The polycarbonate-polysiloxane resin described in the preceding paragraph 1, wherein the polycarbonate block (A-1) contains a structural unit represented by the following formula (1):

(In the above formula (1), ^R1 and ^R2 each independently represent at least one 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 a plurality 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 formula (2):)

(In the above formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent at least one 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 at least one 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.

3. The polycarbonate-polysiloxane resin according to item 1 or 2 above, wherein the polysiloxane block (A-2) contains a structural unit represented by the following formula (3):

(In the above formula (3), R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent at least one group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ²¹ and R ²² each independently represent at least one group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and 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.)

4. The polycarbonate-polysiloxane resin according to any one of items 1 to 3 above, wherein the polycarbonate block (A-1) contains a structural unit represented by the following formula (4):

(In the above formula (4), R ²⁷ and R ²⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and when there are a plurality of each, they may be the same or different, i and j each represent an integer of 1 to 4, and Y represents at least one group selected from the group consisting of groups represented by the following formula (5):

(In the above formula (5), R ²⁹ , R ³⁰ , and R ³¹ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and when there are multiple of each, they may be the same or different, and k is an integer of 1 to 3.)

5. A polycarbonate-polysiloxane resin according to any one of items 1 to 4 above, wherein the structural units of the polycarbonate block (A-1) include units derived from at least one of 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(3-methyl-4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane.

6. The polycarbonate-polysiloxane resin according to any one of paragraphs 1 to 5, wherein the content of the polysiloxane block (A-2) is 5 to 50% by weight based on the entire polycarbonate-polysiloxane resin.

7. The polycarbonate-polysiloxane resin according to any one of items 1 to 4 above, wherein the structural units of the polycarbonate block (A-1) include units derived from 2,2-bis(4-hydroxyphenyl)propane, and the content of the polysiloxane block (A-2) is 30 to 70% by weight based on the entire polycarbonate-polysiloxane resin.

8. The polycarbonate-polysiloxane resin according to any one of items 1 to 7 above, wherein the average number of siloxane repeating units in the polysiloxane block (A-2) is 5 to 100.

9. The polycarbonate-polysiloxane resin according to any one of paragraphs 1 to 8, wherein the average size of the polysiloxane domains of the polycarbonate-polysiloxane resin is 1 to 20 nm.

10. The polycarbonate-polysiloxane resin described in any one of paragraphs 1 to 9 above, wherein a molded article formed from the resin to a thickness of 2 mm has a total light transmittance of 80% or more.

11. A polycarbonate-polysiloxane resin according to any one of items 1 to 10 above, having a pencil hardness of HB or higher.

12. A molded article obtained by molding the polycarbonate-polysiloxane resin according to any one of items 1 to 11 above.
13. A film or sheet obtained by molding the polycarbonate-polysiloxane resin according to any one of items 1 to 11 above.
14. An automobile lamp lens or an automobile interior/exterior component made from the polycarbonate-polysiloxane resin according to any one of items 1 to 11 above.
15. A lighting cover, resin window, or front panel made of the polycarbonate-polysiloxane resin according to any one of items 1 to 11 above.

The polycarbonate-polysiloxane resin of the present invention has excellent transparency, impact resistance, heat resistance, moldability, and pencil hardness, while also having a low specific gravity, making it suitable for use as a component for vehicle bodies, and therefore has exceptional industrial benefits.

The present invention is described in detail below.

<Polycarbonate-polysiloxane resin>
In the present invention, the polycarbonate-polysiloxane resin contains a polycarbonate block (A-1) and a polysiloxane block (A-2).
The polycarbonate-polysiloxane resin of the present invention is characterized by having a specific gravity of 1.10 or less and a glass transition temperature of 100 to 190°C.

(specific gravity)
The specific gravity of the polycarbonate-polysiloxane resin of the present invention is 1.10 or less, preferably 1.09 or less, more preferably 1.08 or less, and even more preferably 1.07 or less. A lower specific gravity is preferable from the viewpoint of weight reduction. The specific gravity is measured in accordance with JIS K7112, Method for measuring density and specific gravity of plastics - non-foamed plastics (Method C, float-sink method).

(glass transition temperature)
The glass transition temperature of the polycarbonate-polysiloxane resin of the present invention is in the range of 90 to 190°C, preferably in the range of 100 to 180°C, more preferably in the range of 110 to 175°C, and even more preferably in the range of 120 to 170°C. A temperature in this range equal to or greater than the lower limit is preferred because the resin has good heat resistance stability when used as a molded article. A temperature in this range equal to or less than the upper limit is preferred because the resin has an appropriate melt viscosity during molding, making it easy to mold thin-walled members and large-area members such as resin windows, and because problems such as thermal degradation are suppressed.

The glass transition temperature is measured using a 2910 DSC manufactured by TA Instruments Japan Co., Ltd. at a heating rate of 20°C/min.

(Polycarbonate Block (A-1))
In the present invention, the polycarbonate block (A-1) is a portion of the polycarbonate polymer contained in the polycarbonate-polysiloxane resin.
Specifically, the polycarbonate block (A-1) preferably contains a structural unit represented by the following formula (1):

In the above formula (1), ^R1 and ^R2 each independently represent at least one 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. 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 2 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 the aralkyl group having 7 to 20 carbon atoms include a benzyl group, a phenylethyl group, etc. Examples of the aralkyloxy group having 7 to 20 carbon atoms include a benzyloxy group, a phenylethyloxy group, etc.
e and f each independently represent an integer of 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 the above formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent at least one 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 at least one 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 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. 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. 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. h is an integer from 4 to 7, preferably an integer from 4 to 5.

The polycarbonate block (A-1) is particularly preferably one containing a structural unit represented by the following formula (4):

In the above formula (4), R ²⁷ and R ²⁸ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. When there are a plurality of R ²⁷ and a plurality of R ²⁸ , they may be the same or different.
i and j are each an integer of 1 to 4.

Y is at least one group selected from the group consisting of groups represented by the following formula (5):

In the above formula (5), R ²⁹ , R ³⁰ and R ³¹ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
k is an integer of 1 to 3.

(Polysiloxane Block (A-2))
In the present invention, the polysiloxane block (A-2) is a polysiloxane-based portion contained in the polycarbonate-polysiloxane resin, and the type thereof is not particularly limited.

Specifically, the polysiloxane block preferably contains a structural unit represented by the following formula (3):

In the above formula (3), R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent at least one group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 12 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 the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, etc. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
It is particularly preferable that R ²³ , R ²⁴ , R ²⁵ and R ²⁶ are methyl groups.

R ²¹ and R ²² each independently represent at least one group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms, and examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

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 preferable that R ²¹ and R ²² each represent a hydrogen atom or a methoxy group.

p is a natural number from 1 to 150, preferably a natural number from 5 to 100, more preferably a natural number from 10 to 80, and particularly preferably a natural number from 20 to 50. The average chain length p is calculated by nuclear magnetic resonance (NMR) measurement.

The repeating unit of p may contain multiple units with different R ^{23 and} R ^24. For example, as shown in the following formula (6), 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 random.

To satisfy this specific chain length range, the polysiloxane may be prepared by mixing two or more different hydroxyaryl-terminated polysiloxane raw materials having an average chain length p. The polysiloxane raw material may be prepared by mixing appropriate polysiloxane raw materials whose ends have been hydroxyaryl-modified, or by pre-mixing polysiloxane precursors having an appropriate average chain length before the ends are hydroxyaryl-modified, and then modifying the ends with hydroxyaryls.

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 groups.

(Other resins)
The polycarbonate-polysiloxane resin of the present invention may contain other resins as long as the effects of the present invention are not impaired. Among these, polycarbonate resins are particularly preferred from the viewpoint of compatibility with the polycarbonate-polysiloxane resin of the present invention.

(Method for producing polycarbonate-polysiloxane resin)
The polycarbonate-polysiloxane resin of the present invention can be produced by steps (I) and (II).

(Step (I))
Step (I) is a step of reacting a dihydric phenol represented by the following formula (7) with phosgene 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 those in formula (1).)

Examples of dihydric phenols represented by the above formula (7) include 4,4'-biphenol, 3,3',5,5'-tetrafluoro-4,4'-biphenol, α,α'-bis(4-hydroxyphenyl)-o-diisopropylbenzene, α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene (hereinafter sometimes abbreviated as "BPM"), α,α'-bis(4-hydroxyphenyl)-p-diisopropylbenzene, α,α'-bis(4-hydroxyphenyl)-m-bis(1,1,1,3,3,3-hexafluoroisopropyl)benzene, 1,1-bis( 1,1-bis(4-hydroxyphenyl)cyclohexane (hereinafter sometimes abbreviated as "BPZ"), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "BPTMC"), 1,1-bis(3-methyl-4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as "BPOCTMC"), 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 1,1-bis(3-cyclohexyl-4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl) Cyclopentane, 1,1-bis(3-fluoro-4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)perfluorocyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfone , 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-diphenyl sulfide, 4,4'-dihydroxy-3,3'-diphenyl sulfoxide, 4,4'-dihydroxy-3,3'-diphenyl sulfone, 1,1-bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (hereinafter sometimes abbreviated as "BPA"), 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane (hereinafter sometimes abbreviated as "BPA"). 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 2,2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 4,4-bis(4-hydroxyphenyl)pentane butane, 2,2-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(3-methyl-4-hydroxyphenyl)decane, 1,1-bis(2,3-dimethyl-4-hydroxyphenyl)decane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (hereinafter abbreviated as "BPAF") (may cause side effects), 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 7,7'-dimethyl-6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 7,7'-diphenyl-6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 2,2-bis(4-hydroxy-3-methylphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane These include 2,2-bis(3-fluoro-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(3,5-difluoro-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, and 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane.

Among the above, BPM, BPZ, BPTMC, BPOCTMC, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide, BPA, BPC, BP26XA, BPAF, 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane, and 1,1-bis(4-hydroxyphenyl)decane are preferred. From the standpoints of impact resistance, heat resistance, low specific gravity, and availability, BPZ, BPTMC, BPOCTMC, BPA, BPC, BP26XA, and BPAF are more preferred, with BPTMC, BPOCTMC, BPA, BPC, and BP26XA being particularly preferred. These dihydric phenols may be used alone or in combination of two or more.

(Step (II))
Step (II) is a step of interfacially polymerizing a hydroxyaryl-terminated polysiloxane represented by the following formula (8) with the carbonate oligomer prepared in step (I) to obtain the polycarbonate-polysiloxane resin of the present invention.

(In the formula, R ²¹ to R ²⁶ , X, and p are the same as those in the formula (3).)

As the hydroxyaryl-terminated polysiloxane represented by formula (8) above, for example, the following compounds are preferably used:

Hydroxyaryl-terminated polysiloxanes are easily produced by subjecting phenols having olefinically unsaturated carbon-carbon bonds, preferably vinylphenol, 2-allylphenol, isopropenylphenol, or 2-methoxy-4-allylphenol, to a hydrosilylation reaction at the end of a polysiloxane chain having a predetermined degree of polymerization. Of these, (2-allylphenol)-terminated polysiloxane and (2-methoxy-4-allylphenol)-terminated polysiloxane are preferred, with (2-allylphenol)-terminated polydimethylsiloxane and (2-methoxy-4-allylphenol)-terminated polydimethylsiloxane being especially preferred. Hydroxyaryl-terminated polysiloxanes may be used alone or in combination of two or more types.

In order to achieve a high level of transparency, the average siloxane repeat number p of the hydroxyaryl-terminated polysiloxane is preferably 1 to 150, more preferably 5 to 100, even more preferably 10 to 80, and especially preferably 20 to 50. At or above the lower limit of this preferred range, excellent impact resistance is achieved, while at or below the upper limit of this preferred range, excellent transparency is achieved. The average chain length p can be calculated by 1H-NMR measurement.

Resins above the lower limit exhibit a significant effect of improving rheological properties through the introduction of polysiloxane moieties with low cohesive strength, making it easier to increase the structural viscosity index. As a result, they maintain high fluidity during shear flow and have good moldability. Resins below the upper limit make it easier to reduce the average size of polysiloxane domains. As a result, resin molded products with excellent transparency can be obtained even under molding conditions where the resin is held in the cylinder at high temperatures for long periods of time. Polysiloxane units below the upper limit increase the number of moles per unit weight, making it easier for the units to be incorporated evenly into the polycarbonate. A high siloxane repeat number leads to uneven incorporation of polysiloxane units into the polycarbonate and an increase in the proportion of polysiloxane units in the polymer molecule. This makes it easier for polycarbonates containing and not containing these units to be produced, and reduces their mutual compatibility. As a result, large polysiloxane domains are more likely to form. On the other hand, from the standpoint of moldability and impact resistance, it is advantageous for the polysiloxane domain to be somewhat larger, and there is a preferred range of repeating numbers as described above.

In the present invention, polysiloxane domains refer to domains primarily composed of polysiloxane dispersed in a polycarbonate matrix, and may contain other components. As mentioned above, polysiloxane domains are not necessarily composed of a single component, since their structure is formed by phase separation from the polycarbonate matrix.

In the polycarbonate-polysiloxane resin of the present invention, the polysiloxane component content relative to the total weight of the resin is preferably 1 to 70% by weight. The lower limit of the polysiloxane component content is preferably 3% by weight or more, 5% by weight or more, 8% by weight or more, 10% by weight or more, 20% by weight or more, 30% by weight or more, 35% by weight or more, or 40% by weight or more. The upper limit is preferably 60% by weight or less, 50% by weight or less, 45% by weight or less, 40% by weight or less, 30% by weight or less, or 20% by weight or less. At or above the lower limit of this preferred range, excellent impact resistance is achieved, while at or below the upper limit of this preferred range, stable transparency that is less susceptible to the effects of molding conditions is likely to be achieved. The polysiloxane content can be calculated by 1H-NMR measurement.

In addition, comonomers other than the above dihydric phenols and hydroxyaryl-terminated polysiloxanes can also be used in combination, as long as they do not interfere with the production method of the present invention.

The polycarbonate-polysiloxane resin of the present invention can be made into a branched polycarbonate resin by using a branching agent in combination with the above-mentioned dihydric phenol compound. Examples of trifunctional or higher polyfunctional aromatic compounds used in such branched polycarbonate resins include phloroglucin, phloroglucside, 4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptene-2,2,4,6-trimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, 2,6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, 4-{4-[1,1-bis(4 Examples include trisphenols such as {4-hydroxyphenyl)ethyl]benzene}-α,α-dimethylbenzylphenol, tetra(4-hydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)ketone, 1,4-bis(4,4-dihydroxytriphenylmethyl)benzene, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and acid chlorides thereof. Of these, 1,1,1-tris(4-hydroxyphenyl)ethane and 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane are preferred, and 1,1,1-tris(4-hydroxyphenyl)ethane is particularly preferred.

The method for producing such branched polycarbonate resins may be one in which a branching agent is included in the mixed solution during the chloroformate compound production reaction, or one in which a branching agent is added during the interfacial polycondensation reaction after the production reaction. The proportion of carbonate structural units derived from the branching agent is preferably 0.005 to 1.5 mol%, more preferably 0.01 to 1.2 mol%, and particularly preferably 0.05 to 1.0 mol%, of the total amount of carbonate structural units constituting the resin. The amount of branched structures can be calculated using 1H-NMR measurement.

In step (I), a mixed solution containing a dihydric phenol oligomer having terminal chloroformate groups is obtained. While stirring the mixed solution, a hydroxyaryl-terminated polysiloxane represented by formula (8) is added at a rate of 0.004 molar equivalents/min or less relative to the amount of dihydric phenol charged, and the hydroxyaryl-terminated polysiloxane and the oligomer are subjected to interfacial polycondensation to obtain a polycarbonate-polysiloxane resin.

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 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 perspective of production efficiency, the lower limit of the dihydric phenol 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 polysiloxane that yields formula (3) 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 an excess amount of alkali relative to the total number of moles of the subsequently added dihydric phenol and hydroxyaryl-terminated polysiloxane (usually 1 mole corresponds to 2 equivalents).

The interfacial polycondensation reaction between the dihydric phenol oligomer and the hydroxyaryl-terminated polysiloxane 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 promote the polycondensation reaction, a catalyst such as a tertiary amine like triethylamine or a quaternary ammonium salt may be added.

The reaction time for such a polymerization reaction needs to be relatively long to reduce unreacted polysiloxane components. It is preferably 30 minutes or more, and more preferably 50 minutes or more. On the other hand, stirring the reaction solution for a long period of time can cause polymer precipitation, so the reaction time is preferably 180 minutes or less, and 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 recommended as heat is generated during polymerization.

If desired, small amounts of antioxidants such as sodium sulfite or hydrosulfide may be added.

(viscosity average molecular weight)
The viscosity average molecular weight of the polycarbonate-polysiloxane resin of the present invention is preferably 15,000 to 40,000, more preferably 16,000 to 35,000, even more preferably 17,000 to 30,000, and particularly preferably 18,000 to 25,000. Within the above range, practical mechanical strength is easily achieved in many fields, and the resin has an appropriate melt viscosity during molding, thereby suppressing problems such as thermal degradation. Furthermore, the difference in melt viscosity from the polycarbonate resin to be mixed as needed is small, resulting in good kneadability. Furthermore, the efficiency of the water washing step during resin production is good, resulting in excellent productivity.

The viscosity average molecular weight of the polycarbonate resin in the present invention is determined by first determining the specific viscosity (ηSP) calculated by the following formula using an Ostwald viscometer from a solution prepared by dissolving 0.7 g of the resin in 100 ml of methylene chloride at 20°C:
Specific viscosity (ηSP) = (t-t ₀ )/t ₀
[t0 is the number of seconds that methylene chloride falls, and t is the number of seconds that the sample solution falls]
The viscosity average molecular weight Mv was calculated from the determined specific viscosity (ηSP) using the following formula:
ηSP/c=[η]+0.45×[η] ² _c (however, [η] is the limiting viscosity)
[η]=1.23×10 ⁻⁴ Mv ^0.83
c=0.7

(Pencil hardness)
The pencil hardness of the polycarbonate-polysiloxane resin of the present invention is preferably 2B or higher. From the viewpoint of excellent scratch resistance, a pencil hardness of HB or higher is more preferable, and a pencil hardness of F or higher is even more preferable. A pencil hardness of 4H or lower provides sufficient functionality. In the present invention, pencil hardness refers to the hardness at which no scratches remain when the resin of the present invention is rubbed with a pencil having a specific pencil hardness, and it is preferable to use the pencil hardness used in the surface hardness test of a coating film that can be measured in accordance with JIS K-5600 as an index. Pencil hardness decreases in the following order: 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, and 6B, with the hardest being 9H and the softest being 6B.

(Impact resistance)
The polycarbonate-polysiloxane resin of the present invention preferably undergoes ductile fracture in a high-speed surface impact test carried out in accordance with JIS K7211-2.

(Total light transmittance)
The total light transmittance of the polycarbonate-polysiloxane resin of the present invention is preferably 80% or more, more preferably 85% or more, and even more preferably 88% or more. The haze value is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. By achieving these values, the appearance of the molded article is excellent, which is preferable. The total light transmittance and haze can be measured in a 2.0 mm thick portion of the obtained resin plate using a Haze Meter NDH 2000 manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with ASTM D1003.

(Domain size)
In the polycarbonate-polysiloxane resin of the present invention, the average size of the polysiloxane domains is preferably in the range of 1 to 20 nm, more preferably in the range of 2 to 15 nm. If the average size is below the lower limit of this range, sufficient impact resistance is not exhibited, and if the average size is above the upper limit of this range, transparency is not stably exhibited.

(Preferred embodiment (1))
In the present invention, in a preferred embodiment (1), the polycarbonate block (A-1) preferably contains, as a structural unit, a unit derived from at least one of 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(3-methyl-4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane.

Furthermore, when the polycarbonate block (A-1) contains the above-mentioned units, the content of the polysiloxane block (A-2) is preferably 1 to 70% by weight, more preferably 3 to 60% by weight, and even more preferably 5 to 50% by weight, based on the entire polycarbonate-polysiloxane resin.

(Preferred embodiment (2))
In the present invention, a preferred embodiment (2) is one in which the structural unit of the polycarbonate block (A-1) contains a unit derived from 2,2-bis(4-hydroxyphenyl)propane, and the content of the polysiloxane block (A-2) is preferably 30 to 70% by weight, more preferably 35 to 60% by weight, and even more preferably 40 to 50% by weight, based on the entire polycarbonate-polysiloxane resin.

(Other ingredients)
The polycarbonate-polysiloxane resin of the present invention can be blended with various flame retardants, reinforcing fillers, and additives that are usually blended with polycarbonate resins, as long as the effects of the present invention are not impaired.

In the present invention, the polycarbonate-polysiloxane resin can be pelletized by melt-kneading using an extruder such as a single-screw extruder or a twin-screw extruder. When producing such pellets, various flame retardants, reinforcing fillers, and additives 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.

(molded product)
In the present invention, various molded articles can be produced from the polycarbonate-polysiloxane resin by injection molding the pellets produced as described above. Furthermore, it is also possible to directly form the resin melt-kneaded in an extruder into sheets, films, profile extrusion molded articles, direct blow molded articles, and injection molded articles without going through the pelletizing 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-polysiloxane resin 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 resin to a specific stretching operation, it can also be molded into heat-shrinkable tubing. The polycarbonate-polysiloxane resin 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 polycarbonate-polysiloxane resin can be subjected to various surface treatments. Surface treatments referred to here involve forming a new layer on the surface of a molded resin 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 resin 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 polycarbonate-polysiloxane resin of the present invention combines excellent transparency, impact resistance, heat resistance, moldability, pencil hardness, and low specific gravity, making it suitable for a wide range of uses in optical components, electrical and electronic equipment, and mobility. It is particularly suitable for use in automotive lamp lenses and automotive interior and exterior components, which are primarily molded by injection molding, and lighting covers, plastic windows, and front panels, which are primarily molded by extrusion molding.

The present invention will be explained in more detail below using 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. Evaluations were performed according to the following methods.

(1) Polymer Composition Ratio Each repeating unit was measured by proton NMR using JNM-AL400 manufactured by JEOL Ltd., and the polymer composition ratio (molar ratio) was calculated.

(2) Polysiloxane Component Content and Average Siloxane Repeat Number The 1H-NMR spectrum of the resulting resin was measured using a JNM-AL400 proton NMR spectrometer manufactured by JEOL Ltd., and the polysiloxane component content was calculated from the integral ratio calculated from the integral curve of the peak derived from the dihydric phenol (for example, 1.4 to 1.8 ppm in the case of BPA) and the integral curve of the peak derived from the polysiloxane (-0.2 to 0.3 ppm). Similarly, the average polysiloxane repeat number was calculated by comparing the integral ratio calculated from the integral curve of the peak derived from the hydroxyaryl terminal and the integral curve of the peak derived from the polysiloxane.

(3) 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 a sample in 100 ml of methylene chloride at 20°C.
Specific viscosity (ηSP) = (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 was calculated from the determined specific viscosity (ηSP) using the following formula:
ηSP/c=[η]+0.45×[η] ² _c (however, [η] is the limiting viscosity)
[η]=1.23×10 ⁻⁴ Mv ^0.83
c=0.7

(4) Glass Transition Temperature Using 8 mg of a sample, a thermal analysis system DSC-2910 manufactured by TA Instruments Co., Ltd. was used to measure the glass transition temperature in accordance with JIS K7121 under the conditions of a nitrogen atmosphere (nitrogen flow rate: 40 ml/min) and a temperature rise rate: 20°C/min.

(5) Moldability The resin was molded into a three-stage resin plate having a width of 50 mm, a length of 90 mm, and a thickness of 3 mm (length 20 mm), 2 mm (length 45 mm), and 1 mm (length 25 mm) from the gate side under conditions of a cylinder temperature of 300 ° C., a mold temperature of 80 ° C., a pressure holding time of 20 seconds, and a cooling time of 20 seconds, and various evaluations were performed. If a three-stage resin plate was obtained under the above conditions, the moldability was evaluated as "○", and if the melt fluidity was poor and a three-stage resin plate could not be obtained, the moldability was evaluated as "×". In the case of moldability "×", the following vacuum hot press molding was performed.

(6) Vacuum hot press molding (Comparative Examples 5, 6, and 12)
The resin was molded into a disk-shaped resin plate with a thickness of 2 mm and a diameter of 5 cm using a vacuum hot press molding machine (Shinto Metal Industries Co., Ltd., compression molding machine: SFV-10, vacuum pump unit: GXD-360), and various evaluations were performed. The press molding conditions were a mold temperature of 300°C, a primary pressure of 1 MPa (30 seconds), and a secondary pressure of 1.5 MPa (5 minutes).

(7) Specific Gravity: Measurement was carried out using a resin plate in accordance with JIS K7112, Method for Measuring Density and Specific Gravity of Plastics - Non-Foamed Plastics (Method C, Float-Sink Method).

(8) Total Light Transmittance and Haze The total light transmittance (%) and haze (%) at a 2.0 mm thick portion of the resin plate were measured using a Haze Meter NDH 2000 manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with ASTM D1003.

(9) Impact Resistance Using a Shimadzu HYDROSHOTHITS-P10 high-speed impact tester (Shimadzu Corporation), the impact resistance was evaluated at a resin plate thickness of 2 mm under the following conditions: test temperature 23°C or -30°C, test speed 7 m/sec, striker diameter 1/2 inch, and receiving diameter 1 inch. The test was carried out five times, and the fracture morphology at each time was visually observed and evaluated according to the criteria described below.
"Good": Ductile fracture was observed 3 or more times out of 5.
"X": Ductile fracture occurred 2 or less times out of 5 times.

(10) Domain Size The three-stage resin plate was cut perpendicular to the resin flow direction using a microtome (EM UC6, manufactured by Leica Microsystems) to prepare ultrathin sections, which were attached to a grid (EM FINE GRID No. 2632 F-200-CU 100PC/CA, manufactured by JEOL Ltd.) and observed at an accelerating voltage of 200 kV using a transmission electron microscope TEM JEM-2100, manufactured by JEOL Ltd. The observation magnification was 20,000 times.

The obtained micrographs were subjected to particle analysis using image analysis software Win ROOF Ver. 6.6 (Mitani Corporation), and the average size and particle size distribution (frequency distribution) of the polysiloxane domains in the sample slices were obtained. Here, the maximum major axis (the length when any two points on the outer contour of the particle are selected so that the distance between them is the maximum) was used as the size of each domain. A similar analysis was performed on five sample slices, and the average value was used as the value for each sample.

(11) Pencil Hardness Based on JIS K5600, a line was drawn on the surface of a resin plate in a thermostatic chamber at an ambient temperature of 23°C with a pencil held at a 45° angle and a load of 750 g applied, and the surface condition was evaluated visually.
Load: 750g
Measurement speed: 50mm/min
Measurement distance: 7 mm
Pencil: Mitsubishi Pencil Hi-uni

<Production of Resin>
(Production Example 1)
A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 13,698 parts of ion-exchanged water and 3,712 parts of a 25% aqueous sodium hydroxide solution, and 2,739 parts of BPA as a dihydric phenol and 5.48 parts of hydrosulfite were dissolved therein. Thereafter, 10,954 parts of methylene chloride and 1,650 parts of a 25% aqueous sodium hydroxide solution were added, and 1,480 parts of phosgene (hereinafter sometimes abbreviated as "FH") was blown in over 70 minutes at 16 to 24°C with stirring. 1031 parts of a 25% aqueous solution of sodium hydroxide was added, and a solution of 83.2 parts of p-tert-butylphenol dissolved in 5477 parts of methylene chloride was further added. While stirring, a solution of 2757 parts of polydimethylsiloxane (hereinafter sometimes abbreviated as "PDMS") KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a hydroxyaryl-terminated polysiloxane was prepared by dissolving in 5514 parts of methylene chloride, and this solution was added to form an emulsion, followed by vigorously stirring again. With such stirring, 3.3 parts of triethylamine was added when the reaction solution was at 28°C, and the mixture was stirred at a temperature of 26 to 31°C. The reaction was completed by continuing stirring for 1 hour. 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 hydrochloric acid-acidic water. The mixture was then repeatedly washed with ion-exchanged water until the conductivity of the aqueous phase was almost 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 resin powder. After dehydration, the mixture was dried at 100°C for 12 hours in a hot air circulation dryer. The resulting resin had a viscosity average molecular weight of 18,500, a glass transition temperature of 124°C, and a polysiloxane component content of 47.7% by weight.

(Production Example 2)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 3,456 parts of BPTMC, 57.5 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 2,558 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 20,100, the glass transition temperature was 148°C, and the polysiloxane component content was 40.8% by weight.

(Production Example 3)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 3,631 parts of BPTMC, 57.5 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 816 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 20,400, the glass transition temperature was 190°C, and the polysiloxane component content was 17.5 wt%.

(Production Example 4)
This was produced in the same manner as in Production Example 1, except that the dihydric phenols were changed to 771 parts of BPTMC and 2,243 parts of BPC, 43.2 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 784 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 22,900, the glass transition temperature was 121°C, and the polysiloxane component content was 19.7% by weight.

(Production Example 5)
This resin was produced in the same manner as in Production Example 1, except that the dihydric phenols used were 3,202 parts of BPOCTMC and 586 parts of BPC, 43.2 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was 357 parts of PDMS KF-2201 (p=35, manufactured by Shin-Etsu Chemical Co., Ltd.). The viscosity average molecular weight of the resulting resin was 20,200, the glass transition temperature was 166°C, and the polysiloxane component content was 8.1% by weight.

(Production Example 6)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 3214 parts of BP26XA, 57.5 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 570 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity-average molecular weight of the resulting resin was 20,000, the glass transition temperature was 167°C, and the polysiloxane component content was 13.4% by weight.

(Production Example 7)
Except for changing the dihydric phenol to 2,942 parts of BPA and 82.9 parts of p-tert-butylphenol and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 22,500, and the glass transition temperature was 148°C.

(Production Example 8)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 2,930 parts of BPA and the hydroxyaryl-terminated polysiloxane was changed to 160 parts of PDMS KF-2201 (p=35, manufactured by Shin-Etsu Chemical Co., Ltd.). The viscosity-average molecular weight of the resulting resin was 20,300, the glass transition temperature was 143°C, and the polysiloxane component content was 4.2% by weight.

(Production Example 9)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 2904 parts of BPA and the hydroxyaryl-terminated polysiloxane was changed to 519 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 21,500, the glass transition temperature was 135°C, and the polysiloxane component content was 13.5% by weight.

(Production Example 10)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 2889 parts of BPA and the hydroxyaryl-terminated polysiloxane was changed to 719 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 19,400, the glass transition temperature was 129°C, and the polysiloxane component content was 17.2 wt%.

(Production Example 11)
Except for changing the dihydric phenol to 3,713 parts of BPTMC and 57.5 parts of p-tert-butylphenol and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 20,000, and the glass transition temperature was 233°C.

(Production Example 12)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 3,683 parts of BPTMC, 57.5 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 297 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 20,200, the glass transition temperature was 218°C, and the polysiloxane component content was 7.1 wt%.

(Production Example 13)
Except for changing the dihydric phenol to 2944 parts of BPC and 74.3 parts of p-tert-butylphenol and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 24,000, and the glass transition temperature was 124°C.

(Production Example 14)
Except for changing the dihydric phenol to 1472 parts of BPC, 1785 parts of BPTMC, and 74.3 parts of p-tert-butylphenol, and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 20,400, and the glass transition temperature was 173°C.

(Production Example 15)
Except for changing the dihydric phenol to 2,355 parts of BPC, 714 parts of BPTMC, and 74.3 parts of p-tert-butylphenol, and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 22,500, and the glass transition temperature was 141°C.

(Production Example 16)
Except for changing the dihydric phenol to 1914 parts of BPC, 1417 parts of BPOCTMC, and 74.3 parts of p-tert-butylphenol, and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 20,900, and the glass transition temperature was 147°C.

(Production Example 17)
Except for changing the dihydric phenol to 2,355 parts of BPC, 810 parts of BPOCTMC, and 74.3 parts of p-tert-butylphenol, and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 19,100, and the glass transition temperature was 181°C.

(Production Example 18)
Except for changing the dihydric phenol to 3,266 parts of BP26XA and 74.3 parts of p-tert-butylphenol and not using the hydroxyaryl-terminated polysiloxane, a resin was produced in the same manner as in Production Example 1. The viscosity average molecular weight of the resulting resin was 19,600, and the glass transition temperature was 194°C.

(Production Example 19)
This was produced in the same manner as in Production Example 1, except that the dihydric phenol was changed to 2856 parts of BPC, 74.3 parts of p-tert-butylphenol, and the hydroxyaryl-terminated polysiloxane was changed to 1069 parts of PDMS KF-2201 (p=35 (manufactured by Shin-Etsu Chemical Co., Ltd.)). The viscosity average molecular weight of the resulting resin was 19,500, and the glass transition temperature was 96°C.

[Examples 1 to 6]
The resins obtained in Production Examples 1 to 6 were injection molded to prepare three-stage resin plates, and the moldability, specific gravity, total light transmittance, haze, impact resistance, domain size, and pencil hardness were evaluated. The evaluation results are shown in Table 1.

[Comparative Examples 1 to 13]
The resins obtained in Production Examples 7 to 19 were injection molded to prepare three-stage resin plates, and the moldability, specific gravity, total light transmittance, haze, impact resistance, domain size, and pencil hardness were evaluated. The evaluation results are shown in Tables 2 and 3. Comparative Examples 5, 6, and 12 had poor melt fluidity and could not be injection molded.

[Comparative Examples 5, 6, and 12]
For Comparative Examples 5, 6, and 12, the resins obtained in Production Examples 11, 12, and 18 were vacuum hot-press molded into disk-shaped resin plates, and the specific gravity, total light transmittance, haze, and pencil hardness were measured. The evaluation results are shown in Tables 2 and 3.

The polycarbonate-polysiloxane resin of the present invention is recognized to have a high degree of transparency, impact resistance, heat resistance, moldability, pencil hardness, and low specific gravity.

The polycarbonate-polysiloxane resin of the present invention combines excellent transparency, impact resistance, heat resistance, moldability, pencil hardness, and low specific gravity, making it suitable for a wide range of uses in optical components, electrical and electronic equipment, and mobility.

Claims (10)

A polycarbonate-polysiloxane resin comprising a polycarbonate block (A-1) and a polysiloxane block (A-2), wherein the polycarbonate block (A-1) contains a structural unit derived from 2,2 -bis(4-hydroxyphenyl)propane, the content of the polysiloxane block (A-2) being 30 to 70% by weight based on the total weight of the polycarbonate-polysiloxane resin, the specific gravity of the resin being 1.10 or less, and the glass transition temperature of the resin being 100 to 190°C. 2. The polycarbonate-polysiloxane resin according to claim 1, wherein the polysiloxane block (A-2) contains a structural unit represented by the following formula (3):
(In the above formula (3), R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent at least one group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R ²¹ and R ²² each independently represent at least one group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and 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.) 3. The polycarbonate-polysiloxane resin according to claim 1 , wherein the average number of siloxane repeating units in the polysiloxane block (A-2) is 5 to 100. 4. The polycarbonate-polysiloxane resin according to claim 1 , wherein the average size of the polysiloxane domains of the polycarbonate-polysiloxane resin is 1 to 20 nm. 5. The polycarbonate-polysiloxane resin according to claim 1 , wherein a molded article of said resin having a thickness of 2 mm has a total light transmittance of 80% or more. 6. The polycarbonate-polysiloxane resin according to claim 1 , wherein the surface of a molded article obtained by molding the resin has a pencil hardness of HB or higher. A molded article obtained by molding the polycarbonate-polysiloxane resin according to any one of claims 1 to 6 . A film or sheet obtained by molding the polycarbonate-polysiloxane resin according to any one of claims 1 to 6 . An automobile lamp lens or an automobile interior or exterior member made of the polycarbonate-polysiloxane resin according to any one of claims 1 to 6 . A lighting cover, a resin window, or a front panel made of the polycarbonate-polysiloxane resin according to any one of claims 1 to 6 .