Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-12-21
2004-11-09
Yoon, Tae H. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S418000, C524S432000, C524S433000, C525S391000, C525S396000, C525S397000
Reexamination Certificate
active
06815485
ABSTRACT:
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/JP01/03458 which has an International filing date of Apr. 23, 2001, which designated the United States of America.
TECHNICAL FIELD
The present invention relates to novel resin compositions which can be utilized for molded products obtained by injection molding or extrusion molding, that are excellent in the balance among heat resistance, flame retardancy, moldability and mechanical properties, and particularly, are excellent in color tone and less generation of foreign matter.
BACKGROUND ART
In general, polyphenylene ethers are resins having excellent properties, for example, in 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, alloying them with another resin or modification of them have conventionally been conducted.
For example, JP-B-52-19864 (The term “JP-B” as used herein means an “examined Japanese patent publication”) and JP-B-52-30991 propose, as a technique related to modification of polyphenylene ethers, processes for obtaining a functionalized polyphenylene ether by, in the presence of a radical generator, mixing a polyphenylene ether in the solution form with styrene and maleic anhydride or another copolymerizable compound for modification and effecting polymerization for long hours. These processes require a dissolving step, polymerizing step and moreover, solvent removal step, leading to an increase in the cost of equipment and energy.
JP-B-3-52486, U.S. Pat. No. 4,654,405, JP-A-62-132924 (The term “JP-A” as used herein means an “unexamined published Japanese patent application”), U.S. Pat. No. 4,888,397, JP-W-63-500803 (The term “JP-W” as used herein means a “published Japanese national stage of international application”) and JP-A-63-54425 propose processes for obtaining a functionalized polyphenylene ether by mixing, in the presence or absence of a radical generator, a polyphenylene ether with maleic anhydride or another reactive compound for modification and modifying it in a molten state by melt-kneading, etc. In these processes, however, the temperature at which a polyphenylene ether can be melt-kneaded is remarkably high and the melt viscosity of the polyphenylene ether is considerably high. The necessity of a markedly high temperature for reaction causes various problems.
A functionalized polyphenylene ether obtained by the conventional melt-kneading method inevitably goes through processing at a high temperature close to its decomposition temperature so that a color change due to thermal deterioration occurs and this functionalized polyphenylene ether resin involves a problem in color tone. In addition, black foreign matter remains in the molded product as a carbide derived from the polyphenylene ether, causing a lowering in insulation properties or appearance. Accordingly, the functionalized polyphenylene ethers obtained by conventional techniques cannot meet the request of the industrial world sufficiently because of problems in equipment or energy, or insufficient balance among color tone, appearance, heat resistance and mechanical properties.
As a technique related to alloying of a polyphenylene ether with another resin, for example, U.S. Pat. No. 4,386,174 and JP-A-56-115357 propose a process of mixing polymers, for example, a polyphenylene ether and a liquid-crystal polyester, thereby improving melt processability of the polyphenylene ether. The improvement is however not insufficient. JP-A-2-97555 proposes a process of mixing a polyarylene oxide to a liquid-crystal polyester in order to improve solder heat resistance, while U.S. Pat. No. 5,498,689 and JP-A-6-122762 propose a process of mixing an amine-modified polyphenylene ether with a liquid-crystal polyester. Neither process is sufficient for reconciling color tone, less generation of foreign matter, heat resistance and moldability.
An object of the invention is therefore to provide a resin composition which can simultaneously attain color tone, moldability, heat resistance, flame retardancy and mechanical properties at a sufficient level and particularly, is excellent in color tone and less generation of foreign matter.
DISCLOSURE OF THE INVENTION
To achieve the above-described object, the present inventors carried out an extensive investigation. As a result, it was found that a resin composition capable of simultaneously attaining color tone, less generation of foreign matter, moldability, heat resistance and flame retardancy at a sufficient level, particularly being excellent in color tone and less generation of foreign matter can be obtained by mixing a functionalized polypheylene ether resin obtained by a specific modifying method and a liquid-crystal polyester, leading to the completion of the invention.
The present invention therefore provides:
1. A resin composition obtained by melt-kneading:
(A) 99 to 1 wt. % of a functionalized polyphenylene ether resin obtained by reacting a mixture of:
(a) 100 parts by weight of a polyphenylene ether, and
(b) 0.01 to 10.0 parts by weight of a modifier selected from non-aromatic conjugated diene compounds, dienophile compounds having one dienophile group and precursors for these diene or dienophile compounds at a reaction temperature of from room temperature to the melting point of (a); and
(B) 1 to 99 wt. % of a liquid-crystal polyester.
2. The resin composition according to item 1 above, wherein the functionalized polyphenylene ether resin (A) has an average particle size of 10 to 500 &mgr;m.
3. The resin composition according to item 1 above, wherein the reaction temperature for obtaining the functionalized polyphenylene ether resin (A) is within a range of from room temperature to the glass transition point of (a).
4. The resin composition according to item 1 above, wherein the reaction temperature for obtaining the functionalized polyphenylene ether resin (A) is within a range of from 120° C. to 220° C.
5. The resin composition according to item 1 above, wherein the modifier (b) is a compound having, in its molecular structure, at least one of (i) a carbon-carbon double bond and (ii) at least one of carboxyl group, oxidized acyl group, imino group, imide group, hydroxyl group and epoxy group.
6. The resin composition according to item 1 above, wherein the modifier (b) is any one of maleic anhydride, maleic acid, fumaric acid, phenyl maleimide, itaconic acid and glycidyl methacrylate.
7. The resin composition according to item 1 above, wherein the modifier (b) is maleic anhydride.
8. The resin composition according to item 1 above, which further comprises (C) 0.001 to 5 parts by weight of a compound containing a polyvalent metal element based on 100 parts by weight, in total, of (A) and (B).
9. The resin composition according to item 8 above, wherein the compound (C) containing a polyvalent metal element is at least one compound selected from ZnO, ZnS, SnO, SnS, zinc stearate, zinc acetate and MgO.
10. The resin composition according to item 1 above, which further comprises (D) 0.1 to 200 parts by weight of an inorganic filler based on 100 parts by weight, in total, of (A) and (B).
11. The resin composition according to item 8 above, which further comprises (D) 0.1 to 200 parts by weight of an inorganic filler based on 100 parts by weight, in total, of (A) and (B).
12. A heat resistant part obtained by molding a resin composition according to any one of items 1 to 11 above.
13. A heat resistant part according to item 12 above, wherein the heat resistant part is for automobiles or office machines.
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is described more specifically below.
The functionalized polyphenylene ether resin (A) to be used in the invention is obtained by reacting a mixture of (a) 100 parts by weight of a polyphenylene ether and (b) 0.01 to 10.0 parts by weight of
Asahi Kasei Kabushiki Kaisha
Birch & Stewart Kolasch & Birch, LLP
Yoon Tae H.
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