Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2002-03-04
2004-07-06
Sanders, Kriellon A. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S127000, C524S389000, C524S399000, C524S400000, C524S492000, C525S397000, C525S437000
Reexamination Certificate
active
06759460
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel resin composition which is excellent in the balance of impact resistance, chemical resistance and fluidity as well as heat resistance and flame retardancy, and to a method for obtaining the composition.
2. Prior Art
In general, polyphenylene ethers are resins that have excellent properties, for example, heat resistance, hot water resistance, size stability and mechanical and electrical properties, but are accompanied with drawbacks such as poor moldability owing to their high melt viscosity, bad chemical resistance and low impact resistance. With a view to improving such defects of polyphenylene ethers, methods of alloying and modifying polyphenylene ethers have conventionally been conducted.
It is well-known that adding polystyrene to the polyphenylene ethers improves the fluidity of the compositions. However, there are problems, which are, for example, that adding polystyrene impairs the heat resistance and chemical resistance.
As a technique related to alloying of a polyphenylene ether with another resin, for example, JP-A-56-115357 and EP-A-30417 proposed a process of mixing polymers, for example, a polyphenylene ether and a liquid-crystal polyester, thereby improving the melt processability of the polyphenylene ether. This process, however, is not sufficient to improve the impact resistance, chemical resistance and fluidity. JP-A-2-97555 proposed a process of mixing a polyphenylene ether with a liquid-crystal polyester in order to improve solder heat resistance, while JP-A-6-122762 and U.S. Pat. No. 5,498,689 proposed a process of mixing an amine-modified polyphenylene ether with a liquid-crystal polyester. Neither process is sufficient for a balance of impact resistance, chemical resistance, fluidity, heat resistance and flame retardancy. U.S. Pat. No. 5,006,403 proposed a polyphenylene ether resin composition containing fibrillated liquid-crystal polymers which form disperse phases in a continuous phase so as to reinforce the composition. WO 9902607 proposed a composition, which comprises a polyphenylene ether resin and a liquid-crystal polymer with a certain morphology. Neither process is sufficient for a balance of impact resistance, chemical resistance and fluidity.
SUMMARY OF THE INVENTION
An object of the invention is to provide a resin composition which can simultaneously attain excellent impact resistance, chemical resistance, fluidity, heat resistance and flame retardancy, especially very excellent impact resistance, chemical resistance and fluidity.
To achieve the object mentioned above, the present inventors carried out extensive investigations. As a result, it was found that a resin composition capable of simultaneously attaining impact resistance, chemical resistance, fluidity, heat resistance and flame retardancy at an excellent level, particularly being excellent in impact resistance, chemical resistance and fluidity, can be obtained by mixing a specific polyphenylene ether resin and a liquid-crystal polyester, optionally with further components, at a specific ratio, leading to the completion of the invention.
The present invention therefore provides:
1. A resin composition comprising:
(A) 70 to 99 parts by weight of a polyphenylene ether resin, and
(B) 1 to 30 parts by weight of a liquid-crystal polyester,
wherein the polyphenylene ether resin in the composition contains 10 to 30 wt. % of polymer having a molecular weight of 20,000 or less and has a molecular weight distribution (Mw/Mn) of 1.8 to 3.5.
2. The resin composition according to the above item 1, wherein the polyphenylene ether resin contains 10 to 25 wt. % of polymer having a molecular weight of 20,000 or less, and has a molecular weight distribution (Mw/Mn) of 2.0 to 3.0.
3. The resin composition according to the above item 1, further comprising:
(C) 0.1 to 10 parts by weight of a compound containing a monovalent, divalent, trivalent or tetravalent metal element based on 100 parts by weight, in total, of components (A) and (B).
4. The resin composition according to the above item 3, wherein the monovalent, divalent, trivalent or tetravalent metal element is at least one element selected from the group consisting of Zn, Mg, Ti, Sn, Sb, Al and Ge.
5. The resin composition according to the above item 3, wherein component (C) is at least one compound selected from the group consisting of ZnO, zinc acetate, zinc stearate, Mg(OH)
2
, tetrabutoxide titanate and tetraisopropoxy titanate.
6. The resin composition according to any one of the above items 3 to 5, wherein the composition has a morphology comprising a continuous phase and a disperse phase, in which the abundance ratio (R) of Zn and/or Mg in the disperse phase obtained by TEM-EDX is 0.0005 or more and a requirement of Rd>Rm when Rm=0 or 150 Rm>Rd>Rm when Rm≠0 (wherein the abundance ratio (R) of Zn and/or Mg=(the number of L&agr;-rays of Zn and/or Mg)/(the number of K&agr;-rays of C), Rd represents R in the disperse phase, and Rm represents R in the continuous phase) is satisfied.
7. The resin composition according to any one of the above items 1 to 5, further comprising:
(D) 0.05 to 30 parts by weight of a vinyl compound elastomer based on 100 parts by weight, in total, of components (A) and (B).
8. The resin composition according to the above item 7, wherein component (D) is functionalized with an acid anhydride group.
9. The resin composition according to any one of the above items 1 to 5, further comprising:
(E) 0.1 to 10 parts by weight of a flame retardant based on 100 parts by weight, in total, of components (A) and (B).
10. The resin composition according to the above item 9, wherein component (E) is (F) a silicon compound.
11. The resin composition according to the above item 10, wherein component (F) is a silicone.
12. The resin composition according to the above item 10, wherein component (F) is a polyhedral oligomeric silsesquioxane or partially opened polyhedral oligomeric silsesquioxane.
13. The resin composition according to the above item 10, wherein component (F) is a silica.
14. The resin composition according to any one of the above items 10 to 13, further comprising:
(G) a cyclic nitrogen compound, wherein the weight ratio (f/g) of component (F) to component (G) is 0.1 to 10.
15. The resin composition according to the above item 14, wherein component (G) is a melamine, melem or mellon.
16. The resin composition according to the above item 9, wherein component (E) is a phosphorus flame retardant.
17. The resin composition according to the above item 16, wherein the phosphorus flame retardant has the following structure (1):
wherein Q
1
, Q
2
, Q
3
and Q
4
each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom; n represents an integer of 1 or more; m
1
, m
2
, m
3
and m
4
each independently represents an integer of 0 to 3; and X is selected from formula (2):
wherein S
1
, S
2
and S
3
each independently represents a methyl group or a hydrogen atom; and n
1
, n
2
and n
3
each independently represents an integer of 0 to 2.
18. A molded article obtained by molding the resin composition according to any one of the above items 1 to 5, 8 and 10 to 17.
19. The molded article according to the above item 18, wherein the molded article is a heat resistant part for automobiles or office machines.
20. The molded article according to the above item 18, wherein the molded article is a sheet.
21. A method for producing the composition according to the above item 1 or 2 comprising:
providing a twin-screw extruder, and
melt-kneading a resin with the twin-screw extruder set at a screw rotation speed (N) of 200 to 600 rpm, heat exposure (&agr;) of 50 or less and a temperature of the resin extruded from a die of 310 to 380° C. (wherein heat exposure (&agr;)=D
3
×N/Q×10
−4
; D (mm)=diameter of the screw of the twin-screw extruder; N (rpm)=screw rotation speed; and Q (kg/hr)=extrusion rate of the resin from the extruder).
22. A resin com
Ikeda Masanori
Kamo Hiroshi
Kuga Shingo
Ono Takashi
Asahi Kasei Kabushiki Kaisha
Sanders Kriellon A.
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