Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-02-11
2002-05-21
Short, Patricia A. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S138000, C525S390000, C525S428000, C525S429000, C525S442000, C525S443000, C525S465000, C525S497000, C525S500000, C528S158000, C528S163000
Reexamination Certificate
active
06391967
ABSTRACT:
FIELD OF THE INVENTION
This invention discloses a flame retarding thermoplastic resin composition, which is comprised of (i) a thermoplastic resin and (ii) a phenolic resin compound as a flame retardant, wherein the phenolic resin compound contains a nitrogen-containing heterocycle and phosphorus.
Since the flame retarding thermoplastic resin composition of this invention does not contain halogen, and has excellent flame retardant properties and high heat resistance, it is useful in producing parts and products in the fields of electronics, electricity and automobile.
The flame retarding thermoplastic resin composition of this invention does not contain halogen and diantimony trioxide. However, its flame retardant properties meet the UL94V-0 standard and it has high heat resistance. Besides, the flame retarding thermoplastic resin composition of this invention has improved the sagging property of the resin compound and solves the problem of migration of the flame retardant in the resin compound, while it retains the easy processing property and good physical properties of a thermoplastic resin.
BACKGROUND OF THE INVENTION
While thermoplastic resins are widely applied in various fields, they have the considerable defect of burning easily and falling in droplets when in contact with fire. In order to overcome this problem, generally, a flame retardant is added into the thermoplastic resin to improve its resistance to fire. But, the burning of the additive cause additional problems. For example, if the added flame retardant contains halides such as bromides, toxic smoke and gases are released when burning or at high temperatures. Especially, highly toxic polybromofurans and polybromodioxins are produced when burning the brominated aromatic compounds, and will seriously affect the health of humans and the environment. Even if they are not burned, both the recovery and the treatment of the waste material from large amounts of these flame retardants will all cause problems as far as the environment is concerned. Therefore, the development of a flame retardant not containing halogen is eagerly required for the thermoplastic resins.
Among the halogen-free flame retardant system being currently developed, the phosphorus and the nitrogen flame retardant systems drew the most attention. With regard to phosphorus compounds as the flame retardant of a thermoplastic resin, it is known that EP 491,986, EP 685,518 and U.S. Pat. No. 5,733,957 disclose an aromatic phosphate oligomer which is used as a flame retardant; JP-A-Hei-10-60160 discloses an aromatic phosphate oligomer which is used as a flame retardant, in coordination with other flame retardants or flame retardant auxiliaries such as silicon compounds; JP-A-Hei-10-251497, JP-A-Hei-11-21458 and U.S. Pat. No. 5,733,957 disclose red phosphorus and phosphate compounds as flame retardants, respectively; in addition, JP-A-Hei-7-292050 discloses using phosphate compounds such as phenolics as flame retardants. As well, U.S. Pat. No. 4,278,591 and U.S. Pat. No. 5,618,865 disclose using nitrogen compounds derived from melamines as the flame retardant of a thermoplastic resin. Further, there are more flame retardant systems of the thermoplastic resin which are comprised of phosphorus compounds in combination with nitrogen compounds, used to reinforce the flame retarding effect, and improve thermal and melt processing properties. These are all exemplified as in the disclosed U.S. Pat. No. 5,814,690, JP-A-Hei-10-175985 and JP-A-Hei-9-296120.
The present inventors have made extensive studies on increasing the flame retarding properties of a thermoplastic resin, while maintaining or improving its processing, physical and mechanical properties. Thus they have devised a novel thermoplastic resin not containing halogen and completed this invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention discloses a flame retarding thermoplastic resin composition, which is comprised of (i) a thermoplastic resin and (ii) a phenolic resin compound as a flame retardant, wherein the phenolic resin compound contains a nitrogen-containing heterocycle and phosphorus.
The term “thermoplastic resin” in this invention means a resin which is flowable after heating and can then be processed and molded. The specific examples of the thermoplastic resins include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystalline polyesters, aromatic polyesters, polycarbonates, polyamides, aromatic polyamides, polyimides, polystyrenes, polyphenyl ethers, polyether sulfones, polysulfones, acrylonitrile-butadiene-styrene (ABS) copolymers, and the like. These resins can be used alone or two or more of them can be mixed.
The phenolic resin compound used as a flame retardant in the flame retarding thermoplastic composition of this invention, which contains a nitrogen-containing heterocycle and phosphorus, is characterized as having the following repeating units:
wherein R
1
and R
2
may be the same or different and independently represent H, a C
1-20
alkyl group, a phenoxy group, a phenyl-C
1-4
alkyl group or a phenyl-C
1-4
alkyl group where a hydroxy group is substituted on the benzene ring, and
R
a
represents a single bond, a phenylene group which may be substituted with a C
1-4
alkyl group,
or —C(R
3
)H—, wherein R
3
represents H, a C
1-4
alkyl group, CH
2
═CH—, phenyl, furanyl, a C
1-4
alkyl-phenyl group or a C
1-4
alkyl-phenyl group where a hydroxy group is substituted on the benzene ring;
(b) a phosphorus-containing repeating unit which is selected from any one of the following formula (b1) or (b2):
wherein R
1
, R
2
and R
a
are defined as above,
X represents an oxygen atom or an ion pair,
T represents an oxygen atom or a chemical linkage, and
R′ and R″ may be the same or different and independently represent a C
1-18
alkyl group, phenyl and a phenyl-C
1-6
alkyl group, or R′ and R″ can be combined together, so that
represents
wherein R
i
and R
j
may be the same or different and independently represent a hydrogen atom or a C
1-18
alkyl group; or
wherein each symbol is defined as above; and
wherein R
b
represents H, a C
1-4
alkyl group, CH
2
═CH—, phenyl, furanyl, a C
1-4
alkyl-phenyl group or a C
1-4
alkyl-phenyl group where a hydroxy group is substituted on the benzene ring, and
Y represents
wherein R
c
represents NH
2
, OH, a C
1-10
alkyl group, phenyl or benzoyl.
Examples of the C
1-4
alkyl group of “a C
1-4
alkyl group”, “a C
1-4
alkyl-phenyl group” or “a C
1-4
alkyl-phenyl group wherein a hydroxy group is substituted on the benzene ring” represented by R
a
and R
b
include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, and the like.
Examples of the C
1-6
alkyl group of “a phenyl-C
1-6
alkyl group” represented by R′ and R″ include those exemplified above for a C
1-4
alkyl group, and pentyl, hexyl, and the like.
Examples of a C
1-10
alkyl group represented by R
c
include those exemplified above for a C
1-6
alkyl group, and heptyl, octyl, nonyl, decyl, and the like.
Examples of a C
1-18
alkyl group represented by R′ and R″ include those exemplified above for a C
1-10
alkyl group, and undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, and the like.
Examples of a C
1-20
alkyl group represented by R
1
and R
2
include those exemplified above for a C
1-18
alkyl group, and nondecyl, eicosyl, and the like.
The repeating unit (a) of the phosphorus-containing polymer having phenolic units of this invention is derived from phenolic resins, such as phenolic resin, phenyl phenolic resin, cresol phenolic resin, xylenol phenolic resin, phenol phenolic resin, isobutylphenol phenolic resin, nonylphenol phenolic resin, bisphenol A phenolic resin, bisphenol F phenolic resin, bisphenol phenolic resin, melamine phenolic resin and polyhydric phenols having the following repeating unit:
wherein R
1
and R
2
are defined as above, and z is an integer from 1 to 10.
The repeating unit (b1) of the phenolic resin co
Chen Hong-Hsing
Hwang Kuen-Yuan
Liu Ying-Ling
Tsai Wen-Tsai
Chang Chun Plastics Co. Ltd.
Corless Peter F.
Edwards & Angell LLP
Jensen Steven M.
Short Patricia A.
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