Polycarbonate resin composition, method for producing same and molded article of this resin composition

Patent metadata

Field	Value
Publication number	US-9777152-B2
Application number	US-201213632957-A
Country	US
Kind code	B2
Filing date	Oct 1, 2012
Priority date	Mar 31, 2010
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

To provide a polycarbonate resin composition excellent in surface hardness and impact strength.
A polycarbonate resin composition comprising at least a polycarbonate resin (a) and a polycarbonate resin (b) having structural units different from the polycarbonate resin (a), which satisfies the requirements:
(i) the pencil hardness of the polycarbonate resin (a) as specified by ISO15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO15184; (ii) the weight ratio of the polycarbonate resin (a) to the polycarbonate resin (b) in the polycarbonate resin is from 1:99 to 45:55; (iii) the pencil hardness of the polycarbonate resin composition as specified by ISO15184 is higher by at least two ranks than the pencil hardness of the polycarbonate resin (b) as specified by ISO15184; and (iv) the Charpy impact strength of the polycarbonate resin composition is higher than the Charpy impact strength of the polycarbonate resin (a).

First claim

What is claimed is:

1. A polycarbonate resin composition comprising at least a polycarbonate resin (a) and a polycarbonate resin (b) having structural units different from the polycarbonate resin (a), wherein the polycarbonate resin (b) has bis-phenol A structural units, which satisfies the following requirements:
(i) the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184;
(ii) the weight ratio of the polycarbonate resin (a) to the polycarbonate resin (b) is from 10:90 to 30:70;
(iii) the pencil hardness of the polycarbonate resin composition as specified by ISO 15184 is higher by at least two ranks than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184;
(iv) the Charpy impact strength of the polycarbonate resin composition is higher than the Charpy impact strength of the polycarbonate resin (a), and
(v) the Charpy impact strength of the polycarbonate resin composition is at least 8 kJ/m 2 , wherein the Charpy impact strength is measured according to JIS K7111 on a molded specimen having a notch of 0.25 mmR,
wherein the polycarbonate resin (a) is a polycarbonate resin having structural units derived from a compound represented by the following formula (1a):

2. A polycarbonate resin composition comprising at least a polycarbonate resin (a) and a polycarbonate resin (b) having structural units different from the polycarbonate resin (a), wherein the polycarbonate resin (b) has bis-phenol A structural units, which satisfies the following requirements:
(i) the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184;
(ii) the weight ratio of the polycarbonate resin (a) to the polycarbonate resin (b) is from 10:90 to 30:70;
(iii) the ratio of the viscosity average molecular weight Mv(a) of the polycarbonate resin (a) to the viscosity average molecular weight Mv(b) of the polycarbonate resin (b), Mv(a)/Mv(b), is at least 0.02 and at most 1.5, and
(iv) the Charpy impact strength of the polycarbonate resin composition is at least 8 kJ/m 2 , wherein the Charpy impact strength is measured according to JIS K7111 on a molded specimen having a notch of 0.25 mmR,
wherein the polycarbonate resin (a) is a polycarbonate resin having structural units derived from a compound represented by the following formula (1a):

3. The polycarbonate resin composition according to claim 2 , wherein the above Mv(a) is at most 20,000.

4. A polycarbonate resin composition comprising at least a polycarbonate resin (a) and a polycarbonate resin (b) having structural units different from the polycarbonate resin (a), wherein the polycarbonate resin (b) has bis-phenol A structural units, which satisfies the following requirements:
(i) the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184;
(ii) wherein the weight ratio of the polycarbonate resin (a) to the polycarbonate resin (b) is from 10:90 to 30:70;
(iii) the melt viscosity of the polycarbonate resin (b) at a temperature of 280° C. at a shear rate of 122 sec −1 is higher than the melt viscosity of the polycarbonate resin (a) at a temperature of 280° C. at a shear rate of 122 sec −1 , and
(iv) the Charpy impact strength of the polycarbonate resin composition is at least 8 kJ/m 2 , wherein the Charpy impact strength is measured according to JIS K7111 on a molded specimen having a notch of 0.25 mmR,
wherein the polycarbonate resin (a) is a polycarbonate resin having structural units derived from a compound represented by the following formula (1a):

5. The polycarbonate resin composition according to claim 1 , wherein the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is at least F.

6. The polycarbonate resin composition according to claim 1 , wherein the pencil hardness of the polycarbonate resin composition as specified by ISO 15184 is at least HB.

7. The polycarbonate resin composition according to claim 1 , which has a yellowness index (YI) of at most 4.0.

8. The polycarbonate resin composition according to claim 1 , which further contains a flame retardant.

9. A method for producing the polycarbonate resin composition as defined in claim 1 , which comprises melt-kneading the polycarbonate resin (a) and the polycarbonate resin (b).

10. A method for producing the polycarbonate resin composition as defined in claim 1 , which comprises dry-blending the polycarbonate resin (a) and the polycarbonate resin (b).

11. An injection-molded article, which is obtained by injection-molding the polycarbonate resin composition as defined in claim 1 .

12. An extruded article, which is obtained by extruding the polycarbonate resin composition as defined in claim 1 .

13. The extruded article according to claim 12 , which is a sheet or a film.

14. A molded article of polycarbonate resin having structural units (a) derived from a compound represented by the following formula (1a) and structural units (b) different from the structural units (a), wherein the structural units (b) are bis-phenol A units and wherein the weight ratio of the structural units (a) to the structural units (b) is from 10:90 to 30:70 based on the total weight of the structural units (a) and the structural units (b), wherein the ratio of the content [S] of the structural units (a) on the surface of the molded article of polycarbonate resin to the content [T] in the entire molded article of polycarbonate resin ([S]/[T]) is higher than 1.00 and at most 2.00:

15. The molded article of polycarbonate resin according to claim 14 , which is an injection-molded article.

16. The molded article of polycarbonate resin according to claim 14 , wherein the ratio of the content [S] of the structural units (a) on the surface of the molded article of polycarbonate resin to the content [T] in the entire molded article of polycarbonate resin ([S]/[T]) is at least 1.01 and at most 1.50.

17. The molded article of polycarbonate resin according to claim 14 , wherein the pencil hardness on the surface of the molded article of polycarbonate resin as specified by ISO 15184 is at least HB.

18. The molded article of polycarbonate resin according to claim 14 , which comprises at least a polycarbonate resin (a) having structural units (a) derived from the compound represented by the formula (1a) and the polycarbonate resin (b) having bis-phenol A structural units.

19. The molded article of polycarbonate resin according to claim 18 , wherein the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184.

20. The molded article of polycarbonate resin according to claim 18 , wherein the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is at least F.

21. The molded article of polycarbonate resin according to claim 18 , wherein the viscosity av

Assignees

• Hitomi Tatsuya
• Nishihara Ryouhei
• Yamamoto Masanori
• Nakata Michio
• Nobuyasu Tetsurou
• Uchimura Ryuuji
• Takahashi Kazuyuki
• Tsuruhara Kenji
• Yokoyama Tomonari
• Mitsubishi Chem Corp
• Mitsubishi Engineering-Plastics Corp

Inventors

• Hitomi Tatsuya
• Nishihara Ryouhei
• Yamamoto Masanori
• Nakata Michio
• Nobuyasu Tetsurou
• Uchimura Ryuuji
• Takahashi Kazuyuki
• Tsuruhara Kenji
• Yokoyama Tomonari

Classifications

• C08L69/00 Primary

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• B29K2069/00

  Use of PC, i.e. polycarbonates {or derivatives thereof}, as moulding material · CPC title

• C08L2666/18

  Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof · CPC title

• C08K5/42

  Sulfonic acids; Derivatives thereof · CPC title