Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2002-03-15
2003-12-16
Boykin, Terressa M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C264S219000, C524S115000, C528S198000
Reexamination Certificate
active
06664362
ABSTRACT:
DETAILED DESCRIPTION OF THE INVENTION
1. Field of the Invention
The present invention relates to a polycarbonate resin composition having excellent resistance to wet heat and to a molded product of the same. More specifically, it relates to a polycarbonate resin composition which is excellent in resistance to wet heat and further in flame retardancy and to a molded product of the same.
2. Related Art
Polycarbonate resins are widely used in the industrial field because they have excellent mechanical properties and thermal properties. However, since they are inferior in workability and moldability, a large number of polymer alloys of the polycarbonate resins and other thermoplastic resins have been developed. Out of these, polymer alloys of the polycarbonate resins and styrene-based resins typified by ABS resin are widely used in the fields of automobiles, OA equipment, electronic and electric appliances, and the like. To meet recent strong demand for flame retardant resin molded products mainly from the fields of OA equipment and home electric appliances, a large number of studies on the flame retardation of polymer alloys of the polycarbonate resins and ABS resin are under way.
Heretofore, a halogen-based flame retardant having bromine and a flame retardant aid such as antimony trioxide have generally been used in combination in the above polymer alloys. However, to cope with such a problem as the generation of a harmful substance at the time of combustion, studies on flame retardation without using a halogen-based compound having bromine are now being made energetically. For example, there are now proposed a method of blending triphenyl phosphate and polytetrafluoroethylene having fibril formability into a polymer alloy of a polycarbonate resin and ABS resin (JP-A 2-32154) (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), a method of blending a phosphate-based oligomer which is a condensation phosphoric ester (JP-A 2-115262), a method of blending a specific inorganic filler and a specific impact modifier (JP-A 7-126510), and the like. Meanwhile, great importance is being attached to performance retainability in long-term use from the viewpoints of product safety, a reduction in the load of environment due to the extension of the service life of a product and product quality warranted by manufacturers.
However, a polycarbonate resin composition comprising a phosphate-based flame retardant has such a problem that when it is used for a long time, the blended phosphate-based flame retardant is hydrolyzed and the hydrolyzed product promotes the hydrolysis of the carbonate bonds of a polycarbonate resin, thereby greatly reducing impact strength and the like. That is, it has been desired to improve the wet heat resistance of a resin composition prepared by blending a phosphate-based flame retardant into a polymer alloy of a polycarbonate resin and ABS resin and a quick solution to this has been awaited.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a polycarbonate resin composition prepared by blending a phosphate-based flame retardant into a polymer alloy of a polycarbonate resin and a styrene-based resin, which has excellent resistance to wet heat.
It is a second object of the present invention to provide a polycarbonate resin composition prepared by blending a phosphate-based flame retardant and polytetrafluoroethylene having fibril formability as a drip-proof agent into a polymer alloy of a polycarbonate resin and a styrene-based resin, which is excellent in resistance to wet heat, impact resistance, flame retardancy and coloring.
It is a third object of the present invention to provide a polycarbonate resin molded article which attains V-0 rating in an UL standard 94V flammability test and rarely experiences reductions in impact strength and molecular weight under such conditions as relatively high temperature and high humidity.
The inventor of the present invention conducted studies to attain the above objects of the present invention and found that a polycarbonate resin composition having excellent flame retardancy and also long-term resistance to hydrolysis (resistance to wet heat) is obtained by controlling the content of a chlorine compound in the composition below a specific value and blending a specific type of inorganic filler when a phosphate-based flame retardant is blended into a polymer alloy of a polycarbonate resin and a styrene-based resin. Thus, the present invention was accomplished based on this finding.
According to the present invention, firstly, the above objects and advantages of the present invention are attained by a polycarbonate resin composition (may be referred to as “resin composition-I” hereinafter) which comprises:
(A) 40 to 92 wt % of an aromatic polycarbonate resin (component “a”);
(B) 5 to 40 wt % of a styrene-based resin (component “b”);
(C) 3 to 20 wt % of a phosphate-based flame retardant (component “c”); and
(D) 0.1 to 30 parts by weight of a silicate filler (component “d”) based on 100 parts by weight of the total of the components “a”, “b” and “c”, and
which has a chlorine compound content in terms of chlorine atoms of 100 ppm or less.
Secondly, the above objects and advantages of the present invention are attained by a polycarbonate resin composition (may be referred to as “resin composition-II” hereinafter) which comprises:
(A) 40 to 92 wt % of an aromatic polycarbonate resin (component “a”);
(B) 5 to 40 wt % of a styrene-based resin (component “b”);
(C) 3 to 20 wt % of a phosphate-based flame retardant (component “c”);
(D) 0.1 to 30 parts by weight of a silicate filler (component “d”) based on 100 parts by weight of the total of the components “a”, “b” and “c”;
(E) 0.1 to 2 parts by weight of polytetrafluoroethylene (component “e”) having fibril formability based on 100 parts by weight of the total of the components “a”, “b” and “c”; and
(F) 1 to 10 parts by weight of a (meth)acrylate-based core-shell graft copolymer (component “f-1”) based on 100 parts by weight of the total of the components “a”, “b” and “c”, and
which has a chlorine compound content in terms of chlorine atoms of 100 ppm or less.
The term “resin composition” in the present invention generally refers to both the resin composition-I and the resin composition-II.
The present invention provides a resin composition which has improved resistance to wet heat (resistance to hydrolysis) and experiences an extremely small reduction in impact strength during its long-term use by controlling the content of a chlorine compound to 100 ppm or less in terms of chlorine atoms and blending a specific amount of a silicate filler into a resin composition which comprises a polycarbonate resin, styrene-based resin and phosphate-based flame retardant.
The polycarbonate resin composition of the present invention will be described in detail hereinunder.
A description is first given of each of the components constituting the resin composition.
(A) Polycarbonate Resin (Component “a”)
The polycarbonate resin which is the component “a” in the present invention is a polycarbonate resin obtained by reacting a diphenol with a carbonate precursor, namely, an aromatic polycarbonate resin. Typical examples of the diphenol used herein include 2,2-bis(4-hydroxyphenyl)propane (to be referred to as “bisphenol A” hereinafter), 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfone and the like. The diphenol is preferably a 2,2-bis(4-hydroxyphenyl)alkane, particularly preferably bisphenol A. The carbonate precursor is a carbonyl halide, carbonic acid diester, bishaloformate or the like. Illustrative examples of the carbonate precursor include phosgene, diphenyl carbonate, dibischloroformates of diphenols and the like. For the production of a polycarbonate resin by reacting the above diphenol with the carbonate precursor, the diphenols may be used alone or in combination o
Boykin Terressa M.
Sherman & Shalloway
Teijin Chemicals Ltd
LandOfFree
Polycarbonate resin composition and molded article does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polycarbonate resin composition and molded article, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polycarbonate resin composition and molded article will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3156117