U.S. patent application number 09/147114 was filed with the patent office on 2001-08-09 for flame retardant plastic resin composition.
This patent application is currently assigned to KANEKA CORPORATION. Invention is credited to FUJITA, KATSUTOYO, HIROBE, KAZUSHI, KOYAMA, TADASHI, MATSUMOTO, KAZUAKI, OHARA, YOICHI, ONO, YOSHITAKA.
Application Number | 20010012865 09/147114 |
Document ID | / |
Family ID | 27312155 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012865 |
Kind Code |
A1 |
MATSUMOTO, KAZUAKI ; et
al. |
August 9, 2001 |
FLAME RETARDANT PLASTIC RESIN COMPOSITION
Abstract
The invention relates to a flame-retardant thermoplastic resin
composition having incorporated therein a trace of stabilized red
phosphorus, which achieves both improvement of heat resistance and
flame retardation without using chlorine nor bromine and also
possesses long-term heat stability and smells little. The
composition comprises (A) 50 to 95 parts by weight of a
polycarbonate resin and (B) 5 to 50 parts by weight of a
thermoplastic polyester resin, contains (C) 0.1 to 5 parts by
weight, per 100 parts by weight of the total amount of (A) and (B),
of coated stabilized red phosphorus and preferably contains (D) 0.1
to 100 parts by weight, per 100 parts by weight of the total amount
of (A) and (B), of a silicate compound.
Inventors: |
MATSUMOTO, KAZUAKI; (OSAKA,
JP) ; KOYAMA, TADASHI; (OSAKA, JP) ; ONO,
YOSHITAKA; (OSAKA, JP) ; FUJITA, KATSUTOYO;
(OSAKA, JP) ; OHARA, YOICHI; (OSAKA, JP) ;
HIROBE, KAZUSHI; (OSAKA, JP) |
Correspondence
Address: |
ARMSTRONG,WESTERMAN, HATTORI,
MCLELAND & NAUGHTON, LLP
1725 K STREET, NW, SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
KANEKA CORPORATION
OSAKA
JP
|
Family ID: |
27312155 |
Appl. No.: |
09/147114 |
Filed: |
October 6, 1998 |
PCT Filed: |
April 2, 1997 |
PCT NO: |
PCT/JP97/01140 |
Current U.S.
Class: |
524/80 ;
524/414 |
Current CPC
Class: |
C08K 5/523 20130101;
C08L 69/00 20130101; C08K 5/523 20130101; C08L 69/00 20130101; C08L
67/02 20130101; C08L 69/00 20130101 |
Class at
Publication: |
524/80 ;
524/414 |
International
Class: |
C08K 003/00; C08K
003/32 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 8, 1996 |
JP |
P.HEI-8-112014 |
Aug 27, 1996 |
JP |
P.HEI-8-245571 |
Oct 22, 1996 |
JP |
P.HEI-8-279655 |
Claims
1. A flame-retardant thermoplastic resin composition comprising (A)
50 to 95 parts by weight of a polycarbonate resin, (B) 5 to 50
parts by weight of a thermoplastic polyester resin, and (C) 0.1 to
5 parts by weight, per 100 parts by weight of the total amount of
(A) and (B), of coated stabilized red phosphorus.
2. A flame-retardant thermoplastic resin composition according to
claim 1, wherein the composition further contains (D) 0.1 to 100
parts by weight of a silicate compound per 100 parts by weight of
the total amount of (A) and (B).
3. A flame-retardant thermoplastic resin composition according to
claim 1, wherein the composition further contains (E) 0.01 to 5
parts by weight of a fluorocarbon resin and/or silicone per 100
parts by weight of the total amount of (A) and (B).
4. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 3, wherein the coated stabilized red
phosphorus (C) is present in an amount of 0.1 to 3 parts by weight,
the silicate compound (D) is present in an amount of 0.1 to 100
parts by weight, and the fluorocarbon resin and/or silicone (E) is
present in an amount of 0.01 to 5 parts by weight.
5. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 4, wherein the composition further contains
(F) 0.1 to 30 parts by weight of an organic phosphorus flame
retardant per 100 parts by weight of the total amount of (A) and
(B).
6. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 5, wherein the organic phosphorus flame
retardant (F) is a phosphoric ester represented by formula:
6wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a
monovalent aromatic or aliphatic group; R.sup.5 represents a
divalent aromatic group; n represents a number of from 0 to 16;
nR.sup.3's and nR.sup.5's each may be the same or different.
7. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 6, wherein the composition further contains
(G) 0.1 to 20 parts by weight of at least one elastic resin
selected from a graft polymer and an olefin resin per 100 parts by
weight of the total amount of (A) and (B).
8. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 7, wherein the thermoplastic polyester resin
(B) is a polyalkylene terephthalate having an alkylene
terephthalate unit content of not less than 80% by weight.
9. A flame-retardant thermoplastic resin composition according to
any one of claims 1 to 8, wherein the coated stabilized red
phosphorus (C) is red phosphorus coated with at least one substance
selected from a thermosetting resin, a metal hydroxide, and a
plating metal.
Description
TECHNICAL FIELD
[0001] This invention relates to a flame-retardant thermoplastic
resin composition. More particularly, it relates to a
flame-retardant thermoplastic resin composition having incorporated
therein a trace of stabilized red phosphorus, which achieves both
improvement of heat resistance and flame retardation without using
chlorine nor bromine and also possesses long-term heat stability
and smells little.
BACKGROUND ART
[0002] Polycarbonate resins are thermoplastic resins having
excellent impact resistance and heat resistance and widely used as
parts in the fields of machinery, automobiles, electricity and
electronics. In particular aromatic polycarbonate resins have a
high glass transition temperature and are expected to exhibit high
heat stability. However, they frequently fail to show sufficient
flowability in processing. Therefore, aromatic polycarbonate resins
should be processed at relatively high processing temperatures
around 300.degree. C. In molding aromatic polycarbonate resins by,
for example, injection molding, relatively high injection speed and
pressure are required.
[0003] On the other hand, thermoplastic polyester resins are
excellent in mechanical properties, electrical properties, and
chemical resistance and exhibit satisfactory flowability on being
heated at or above their crystal melting point and therefore have
been used widely as fiber, film and a molding material.
[0004] It has been attempted to improve the flowability and the
like of polycarbonate resins by taking advantage of these
characteristics of the thermoplastic polyester resin. For example,
JP-B-36-14035 (the term "JP-B" as used herein means an "examined
published Japanese patent application"), JP-B-39-20434, and
JP-A-59-176345 (the term "JP-A" as used herein means an "unexamined
published Japanese patent application") propose a polycarbonate
resin composition containing a polyester resin, such as
polyethylene terephthalate, polybutylene terephthalate, etc.
[0005] In order to secure safety against fire, thermoplastic resins
are often required to have such flame retardance as to meet the
standards of UL-94 V-0 or 5V (Underwriter's Laboratories Standard,
U.S.A.). Various flame retardants have been developed and studied
for this purpose.
[0006] Recent environmental concerns growing particularly in Europe
have promoted the study on the use of halogen-free flame
retardants, such as phosphorus type flame retardants. Useful
phosphorus type flame retardants include organic phosphorous
compounds and red phosphorus.
[0007] Known organic phosphorus compounds include those disclosed
in JP-A-63-227632, JP-A-5-1079, and JP-A-5-279513. Compositions
which are made flame-retardant by addition of an organic phosphorus
flame retardant include the flame-retardant resin composition of
JP-A-5-179123, which comprises a polycarbonate resin and other
resins and contains an organic phosphorus flame retardant, a boron
compound, organopolysiloxane, and a fluororesin, and the
flame-retardant resin composition of JP-A-6-192553, which comprises
a polycarbonate resin and a polyalkylene terephthalate resin and
contains a graft copolymer, an oligomeric organic phosphorus flame
retardant, and a fluorinated polyolefin.
[0008] Known red phosphorous species include those described in
JP-B-54-39200, JP-A-55-10463, and JP-B-5-8125. Compositions which
are made flame-retardant with red phosphorus include
flame-retardant resin compositions comprising a polycarbonate resin
and powdered red phosphorus as disclosed in JP-A-48-85642 and
JP-A-50-78651.
[0009] Red phosphorus is difficult to handle because for one thing
it is a dangerous chemical having a danger of dust explosion and
for another it tends to emit smell or gas when processed in high
temperature. In order to overcome these problems, various
techniques for coating the surface of red phosphorus for
stabilization have been proposed. For example, JP-A-52-142751,
JP-B-5-18356, and JP-A-5-239260 disclose red phosphorus coated with
a thermosetting resin, aluminum hydroxide, etc. or electrolessly
plated red phosphorus and thermoplastic resins which are rendered
flame-retardant by addition of the thus stabilized red
phosphorus.
[0010] JP-B-2-37370 proposes a flame-retardant resin composition
comprising a polyester resin and thermosetting resin-coated red
phosphorus and, if desired, a reinforcing filler. JP-A-5-239260 and
JP-A-5-247264 disclose a flame-retardant resin composition
comprising a thermoplastic resin such as a polycarbonate alloy, a
polyester resin, etc. and electrolessly plated red phosphorus.
[0011] In the fields where such flame-retardant resin compositions
are used as, for example, electric and electronic parts,
simplification of assembly and cost reduction have been desired,
and it has been promoted to make parts integral-or thinner.
Therefore, materials used in these parts are required to show
satisfactory flowability in molding and to maintain high heat
resistance and high flame retardance.
[0012] However, addition of an organic phosphorus flame retardant
to a polycarbonate resin in an attempt to impart sufficient flame
retardance results in considerable reduction in heat
resistance.
[0013] Polycarbonate resin compositions containing red phosphorus
or stabilized red phosphorus lack long-term heat stability. That
is, moldings obtained suffer from deformation when exposed to a
temperature no higher than around 150.degree. C. for a long time.
Besides, the compositions have poor molding processability because
of low flowability. If the compositions are molded at high
temperatures to secure flowability, there arise different problems
such that a smell attributable to red phosphorus issues during
molding and that decomposition gas generates during molding to
contaminate the mold.
[0014] In addition it is difficult with red phosphorus alone to
obtain sufficient flame retardance. It means that red phosphorus
should be used either in a large quantity or in combination with
another flame retardant or a flame retardation aid. However,
addition of a large quantity of red phosphorus leads to a stronger
smell attributable to red phosphorus, and a combined use of a flame
retardation aid results in not only destruction of the balance of
properties of the resin but an increase of cost.
DISCLOSURE OF INVENTION
[0015] The inventors have conducted extensive investigation on red
phosphorus-containing flame-retardant resin compositions. As a
result, they have surprisingly found that improvements in heat
resistance and long-term heat stability result when stabilized red
phosphorus is added to an alloy comprising a polycarbonate resin
and a polyester resin as compared with the alloy containing no
stabilized red phosphorus and that this effect is never be observed
with other thermoplastic resins. They have ascertained that
addition of only a trace amount of stabilized red phosphorus to a
polycarbonate resin-polyester resin alloy produces high flame
retardance to provide a flame-retardant resin composition that
retains the excellent characteristics possessed by the alloy, such
as molding processability, non-smelling properties, and the like.
They have additionally discovered that addition of a combination of
stabilized red phosphorus and a silicate compound brings about
further improvements in not only flame retardance but the
above-mentioned other properties. The present invention has been
reached based on these findings.
[0016] The present invention provides in its first aspect a
flame-retardant thermoplastic resin composition comprising (A) 50
to 95 parts by weight of a polycarbonate resin, (B) 5 to 50 parts
by weight of a thermoplastic polyester resin and (C) 0.1 to 5 parts
by weight, per 100 parts by weight of the total of (A) and (B), of
coated stabilized red phosphorus.
[0017] The present invention provides in its second aspect a
flame-retardant thermoplastic resin composition comprising (A) 50
to 95 parts by weight of a polycarbonate resin, (B) 5 to 50 parts
by weight of a thermoplastic polyester resin and (C) 0.1 to 5 parts
by weight, per 100 parts by weight of the total amount of (A) and
(B), of coated stabilized red phosphorus and (D) 0.1 to 100 parts
by weight, per 100 parts by weight of the total amount of (A) and
(B), of a silicate compound.
[0018] The resin composition of the invention can further contain
one or more of components (E) to (G) hereinafter described.
[0019] In a preferred embodiment of the invention, the
flame-retardant thermoplastic resin composition further contains
(E) 0.01 to 5 parts by weight of a fluorocarbon resin and/or
silicone per 100 parts by weight of the total amount of (A) and
(B).
[0020] In a preferred embodiment of the invention, the
flame-retardant resin composition contains (C) 0.1 to 3 parts by
weight of stabilized red phosphorus, (D) 0.1 to 100 parts by weight
of a silicate compound, and (E) 0.01 to 5 parts of a fluorocarbon
resin and/or silicone, each per 100 parts by weight of the-total
amount of (A) and (B).
[0021] In another preferred embodiment of the invention, the
flame-retardant resin composition further contains (F) 0.1 to 30
parts by weight of an organic phosphorus flame retardant per 100
parts by weight of the total amount of (A) and (B).
[0022] In still another preferred embodiment of the invention, the
flame-retardant resin composition further contains (G) 0.1 to 20
parts by weight of at least one elastic resin selected from graft
polymers and olefin resins per 100 parts by weight of the total
amount of (A) and (B).
[0023] In yet another preferred embodiment of the invention, the
thermoplastic polyester resin as component (B) is a polyalkylene
terephthalate having not less than 80% by weight of an alkylene
terephthalate unit.
[0024] In an additional preferred embodiment of the invention, the
stabilized red phosphorus flame retardant as component (C) is red
phosphorus coated with at least one substance selected from a
thermosetting resin, a metal hydroxide, and a plating metal.
[0025] Polycarbonate resin (A) used in the present invention is
obtained by reacting a di- or polyhydric phenol compound and
phosgene or a carbonic diester such as diphenyl carbonate.
[0026] There are various dihydric phenols usable. Particularly
suitable is 2,2-bis(4-hydroxyphenyl)propane, which is generally
called bisphenol A. Dihydric phenols other than bisphenol A include
dihydroxydiarylalkanes, such as bis(4-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
bis(4-hydroxyphenyl)-(4-isopropylphe- nyl)methane,
bis(3,5-dimethyl-4-hydroxyphenyl)methane,
1,1-bis(4-hydroxyphenyl)ethane,
1-naphthyl-1,1-bis(4-hydroxyphenyl)ethane- ,
1-phenyl-1,1-bis(4-hydroxyphenyl)ethane,
1,2-bis(4-hydroxyphenyl)ethane,
2-methyl-1,1-bis(4-hydroxyphenyl)propane,
2,2-bis(3,5-dimethyl-4-hydroxyp- henyl)propane,
1-ethyl-1,1-bis(4-hydroxyphenyl)propane,
2,2-bis(3-methyl-4-hydroxyphenyl)propane,
1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane,
1,4-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane,
4-methyl-2,2-bis(4-hydroxyphenyl)pentane- ,
2,2-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)heptane,
2,2-bis(4-hydroxyphenyl)nonane, 1,10-bis(4-hydroxyphenyl)decane,
and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane;
dihydroxydiarylcycloalkanes, such as
1,1-bis(4-hydroxyphenyl)cyclohexane and
1,1-bis(4-hydroxyphenyl)cyclodecane; dihydroxydiarylsulfones, such
as bis(4-hydroxyphenyl)sulfone and
bis(3,5-dimethyl-4-hydroxyphenyl)sulfone; dihydroxydiaryl ethers,
such as bis(4-hydroxyphenyl) ether and
bis(3,5-dimethyl-4-hydroxyphenyl) ether; dihydroxydiaryl ketones,
such as 4,4' -dihydroxybenzophenone and
3,3',5,5'-tetramethyl-4,4'-dihydroxybenzo- phenone; dihydroxydiaryl
sulfides, such as bis(4-hydroxyphenyl) sulfide,
bis(3-methyl-4-hydroxyphenyl) sulfide, and
bis(3,5-dimethyl-4-hydroxyphen- yl) sulfide; dihydroxydiaryl
sulfoxides, such as bis(4-hydroxyphenyl) sulfoxide;
dihydroxydiphenyls, such as 4,4' -dihydroxydiphenyl; and
dihydroxyarylfluorenes, such as 9,9-bis(4-hydroxyphenyl)fluorene.
In addition to the dihydric phenols, dihydroxybenzenes, such as
hydroquinone, resorcinol, and methylhydroquinone; and
dihydroxynaphthalenes, such as 1,5-dihydroxynaphthalene and
2,6-dihydroxynaphthalene, are also useful. These dihydric phenols
can be used either individually or as a combination of two or more
thereof.
[0027] Suitable carbonic diester compounds include diaryl
carbonates, such as diphenyl carbonate, and dialkyl carbonates,
such as dimethyl carbonate and diethyl carbonate.
[0028] The polycarbonate resin as component (A) can contain a
branched polycarbonate if desired. Branching agents which can be
used for obtaining branched polycarbonates include phloroglucin,
mellitic acid, trimellitic acid, trimellitic chloride, trimellitic
anhydride, gallic acid, n-propyl gallate, protocatechuic acid,
pyromellitic acid, pyromellitic acid dianhydride,
.alpha.-resorcylic acid, .beta.-resorcylic acid, resorcylaldehyde,
isatinbis(o-cresol), benzophenonetetracarboxylic acid, 2,4,4'
-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone,
2,4,4'-trihydroxyphenyl ether, 2,2',4,4'-tetrahydroxyphenyl ether,
2,4,4'-trihydroxydiphenyl-2-propane,
2,2'-bis(2,4-dihydroxyphenyl)propane- , 2,2',4,4'
-tetrahydroxydiphenylmethane, 2,4,4' -trihydroxydiphenylmethan- e,
1-[.alpha.-methyl-.alpha.-(4'
-dihydroxyphenyl)ethyl]-3-[.alpha.',.alph- a.'-bis(4"
-hydroxyphenyl)ethyl]benzene, 1-[.alpha.-methyl-.alpha.-(4'
-dihydroxyphenyl)ethyl]-4-[.alpha.'.alpha.'-bis(4"
-hydroxyphenyl)ethyl]benzene,
.alpha.,.alpha.',.alpha."-tris(4-hydroxyphe-
nyl)-1,3,5-triisopropylbenzene, 2,6-bis(2-hydroxy-5'
-methylbenzyl)-4-methylphenol, 4,6-dimethyl-2,4,6-tris(4'
-hydroxyphenyl)-heptene, 4,6-dimethyl-2,4,6-tris(4'
-hydroxyphenyl)-heptane, 1,3,5-tris(4'-hydroxyphenyl)benzene,
1,1,1-tris(4-hydroxyphenyl)ethane, 2,2-bis[4,4-bis(4'
-hydroxyphenyl)cyclohexyl]propane,
2,6-bis(2'-hydroxy-5'-isopropylbenzyl)- -4-isopropylphenol,
bis[2-hydroxy-3-(2' -hydroxy-5'-methylbenzyl)-5-methyl-
phenyl]methane,
bis[2-hydroxy-3-(2'-hydroxy-5'-isopropylbenzyl)-5-methylph-
enyl]methane, tetrakis(4-hydroxyphenyl)methane,
tris(4-hydroxyphenyl)pheny- lmethane, 2',4',7-trihydroxyflavan,
2,4,4-trimethyl-2',4',7-trihydroxyflav- an, 1,3-bis(2',4'
-dihydroxyphenylisopropyl)benzene, and tris(4'
-hydroxyphenyl)-amyl-s-triazine.
[0029] In some cases, a polycarbonate-polyorganosiloxane copolymer
composed of a polycarbonate segment and an polyorganosiloxane
segment can be used as polycarbonate resin (A). The degree of
polymerization of the polyorganosiloxane segment is preferably 5 or
more.
[0030] Additionally, polycarbonate resins comprising a comonomer
unit derived from a straight-chain aliphatic dicarboxylic acid,
such as adipic acid, pimelic acid, suberic acid, azelaic acid,
sebacic acid, and decanedicarboxylic acid, can also be used as
component (A).
[0031] Various known polymerization terminators can be used in
producing the polycarbonate resin. Suitable terminators include
monohydric phenols, such as phenol, p-cresol, p-t-butylphenol,
p-t-octylphenol, p-cumylphenol, and nonylphenol.
[0032] For the purpose of increasing flame retardance, copolymers
comprising a phosphorus compound unit or phosphorus
compound-terminated polymers can be used. For improving weather
resistance, copolymers comprising a dihydric phenol unit having a
benzotriazole group can be used.
[0033] Polycarbonate resin (A) which can be used in the present
invention preferably has a viscosity average molecular weight of
10000 to 60000, still preferably 15000 to 45000, particularly
preferably 18000 to 35000. If the viscosity average molecular
weight is less than 10000, the resulting resin composition tends to
have insufficient strength or heat resistance. If it exceeds 60000,
the composition tends to have insufficient molding
processability.
[0034] These polycarbonate resins can be used either individually
or as a combination of two or more thereof. The combination of the
polycarbonate resins is not limited. For example, two or more
resins different in monomer unit, copolymerizing molar ratio and/or
molecular weight can be combined arbitrarily.
[0035] Thermoplastic polyester resin (B) is a resin obtained by
polycondensation of a di- or polycarboxylic acid component, a di-
or polyhydric alcohol and/or phenol component in a known manner.
Examples of useful thermoplastic polyester resins are polyethylene
terephthalate, polypropylene terephthalate, polybutylene
terephthalate, polyhexamethylene terephthalate,
polycyclohexanedimethylene terephthalate, polyethylene naphthalate,
and polybutylene naphthalate.
[0036] Of the di- or polycarboxylic acid components, aromatic
polycarboxylic acid components having 8 to 22 carbon atoms and
ester-forming derivatives thereof are used. Examples thereof
include phthalic acids, such as terephthalic acid and isophthalic
acid; carboxylic acids, such as naphthalenedicarboxylic acid,
bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid,
4,4'-diphenyldicarboxylic acid,
1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid,
diphenylsulfonedicarboxylic acid, trimesic acid, trimellitic acid,
and pyromellitic acid; and ester-forming derivatives thereof. They
can be used either individually or as a combination of two or more
thereof. Preferred of them are terephthalic acid, isophthalic acid,
and naphthalenedicarboxylic acid for their ease of handling and
reacting and excellent physical properties of the resulting
resin.
[0037] Other useful di- or polycarboxylic acid components include
aliphatic ones having 4 to 12 carbon atoms, alicyclic ones having 8
to 15 carbon atoms, and ester-forming derivatives thereof. Examples
are adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic
acid, maleic acid, 1,3-cyclohexanedicarboxylic acid, and
1,4-cyclohexanedicarboxylic acid, and ester-forming derivatives
thereof.
[0038] The ester-forming derivatives of the carboxylic acids are
derivatives capable of forming an ester, such as carboxylic acid
halides (e.g., carboxylic acid chloride) and carboxylic acid
esters.
[0039] The di- or polyhydric alcohol and/or phenol component
includes aliphatic compounds having 2 to 15 carbon atoms, alicyclic
compounds having 6 to 20 carbon atoms and aromatic compounds having
6 to 40 carbon atoms, each of which having two or more hydroxyl
groups per molecule, and ester-forming derivatives thereof.
Examples of such alcoholic and/or phenolic components include
ethylene glycol, propylene glycol, butanediol, hexanediol,
decanediol, neopentyl glycol, cyclohexanedimethanol,
cyclohexanediol, 2,2'-bis(4-hydroxyphenyl)propane,
2,2'-bis(4-hydroxycyclohexyl)propane, hydroquinone, glycerol, and
pentaerythritol, and their ester-forming derivatives. Preferred
alcohol and/or phenol components are ethylene glycol, butanediol,
and cyclohexanedimethanol for their ease of handling and reacting
and excellent physical properties of the resulting resin.
[0040] Thermoplastic polyester resin (B) may further comprise known
copolymerizable component in addition to the above-mentioned acid
component and alcohol and/or phenol component as far as the
characteristics as desired are not impaired.
[0041] Oxyacids, such as p-hydroxybenzoic acid, and their
ester-forming derivatives, cyclic esters, such as .epsilon.
-caprolactone, and the like can also be used as a copolymerizable
component.
[0042] Further, copolymers having copolymerized in the polymeric
chain a polyalkylene glycol unit, such as polyethylene glycol,
polypropylene glycol, poly(ethylene oxide-propylene oxide) block
and/or random copolymers, ethylene oxide-added bisphenol A
copolymers, propylene oxide-added bisphenol A copolymers,
tetrahydrofuran-added bisphenol A copolymers, and
polytetramethylene glycol, can also be used. The proportion of
these copolymer unit is generally 20% by weight or less, preferably
15% by weight or less, particularly 10% by weight or less.
[0043] It is preferred that thermoplastic polyester resin (B) be a
polyalkylene terephthalate, preferably one having an alkylene
terephthalate unit content of 80% by weight or more, particularly
-85% by weight or more, especially 90% by weight or more. Such a
polyalkylene terephthalate provides a resin composition having
well-balanced physical properties, such as moldability.
[0044] It is preferred for thermoplastic polyester resin (B) to
have an intrinsic viscosity (IV) of 0.30 to 2.00 dl/g, still
preferably 0.40 to 1.80 dl/g, particularly preferably 0.50 to 1.60
dl/g, as measured in a phenol/tetrachloroethane (1/1 by weight)
mixed solvent at 25.degree. C. If the intrinsic viscosity is less
than 0.30 dl/g, the resulting moldings tend to have insufficient
flame retardance or mechanical strength. If it exceeds 2.00 dl/g,
the composition tends to have reduced flowability in molding.
[0045] The thermoplastic polyester resins as component (B) can be
used either individually or as a combination of two or more
thereof. The combination is not limited. For example, two or more
resins different in monomer unit, copolymerizing molar ratio and/or
molecular weight can be combined arbitrarily.
[0046] The mixing ratio of polycarbonate resin (A) and
thermoplastic polyester resin (B) is from 95/5 to 50/50, preferably
90/10 to 55/45, still preferably 85/15 to 60/40, by weight. If the
weight ratio of thermoplastic polyester resin (B) in the (A)/(B)
mixture is less than 5, the resulting resin composition has
insufficient molding flowability, and the effect of stabilized red
phosphorus in improving long-term heat stability is insubstantial.
If it exceeds 50, the impact resistance that is characteristic of
polycarbonate resins is reduced.
[0047] Stabilized red phosphorus (C) is red phosphorus having been
stabilized by surface coating through various methods. Red
phosphorus coated with at least one substance selected from a
thermosetting resin, a metal hydroxide, and a plating metal is
preferred. Any thermosetting resin that can coat red phosphorus can
be used without particular limitation. Suitable thermosetting
resins include a phenol-formalin resin, a urea-formalin resin, a
melamine-formalin resin, and an alkyd resin. Any metal hydroxide
that can coat red phosphorus can be used with no particular
limitation. Suitable metal hydroxides include aluminum hydroxide,
magnesium hydroxide, zinc hydroxide, and titanium hydroxide. Any
electrolessly plating film that can coat red phosphorus can be used
with no particular limitation. Examples of the plating metals
include Fe, Ni, Co, Cu, Zn, Mn, Ti, Zr, Al, and their alloys. Two
or more of these coating substances can be used as a mixture or can
be provided in different layers.
[0048] The coated and stabilized red phosphorus is advantageous for
its ease of handling and improved smell.
[0049] The stabilized red phosphorus species can be used either
individually or as a combination of two or more thereof. The
combination is not limited. For example, species different in kind
of the coating substance and/or particle size can be combined
arbitrarily.
[0050] The content of stabilized red phosphorus (C) is 0.1 to 5
parts by weight, preferably 0.3 to 4 parts by weight, still
preferably 0.5 to 3 parts by weight, per 100 parts by weight of the
total of polycarbonate resin (A) and thermoplastic polyester resin
(B). If it is less than 0.1 part, the resulting molded articles
have insufficient flame retardance. If it exceeds 5 parts, the
resin composition gives off smell vigorously.
[0051] It is preferable for the flame-retardant thermoplastic resin
composition of the invention to contain a silicate compound as
component (D). The existence of a silicate, even in a trace amount,
brings about significant improvement in flame retardance. Addition
of a silicate compound also leads to improvements in heat
resistance and elastic modulus. Useful silicate compounds typically
include those containing a chemical composition of an SiO.sub.2
unit. While not limiting, the silicate compound usually has a
particulate shape, a granular shape, a needle-like shape, a tabular
shape, etc. The silicate compound to be used may be either a
natural one or a synthetic one.
[0052] Specific examples of suitable silicate compounds are
magnesium silicate, aluminum silicate, calcium silicate, talc,
mica, wollastonite, kaolin, diatomaceous earth, and smectite.
Preferred are mica, talc, kaolin and smectite because they are
highly effective in not only greatly enhancing flame retardance but
suppressing anisotropy of molded articles and improving heat
resistance and mechanical strength.
[0053] Mica as component (D) is not particularly limited in
species. An arbitrary choice can be made from among commonmica
(muscovite), phlogopite, sericite, biotite, paragonite, synthetic
mica, and the like. The mica can be surface-treated to have
improved adhesion to the resin matrix. A silane coupling agent
containing an epoxy group, such as epoxysilane, is a preferred
surface treating agent; for it will not reduce the physical
properties of the resins. The surface treatment can be carried out
in a conventional manner with no particular restriction.
[0054] It is preferred that the mica to be used has a
weight-average flake diameter of 1 to 40 .mu.m for the reasons
that: the effects in flame retardation and prevention of dripping
are enhanced; the processability in melt kneading is improved; and
the resulting molded articles have improved impact strength. It is
still preferred for the mica to have a weight-average flake
diameter of 2 to 37 .mu.m, particularly 3 to 35 .mu.m. If the
weight-average flake diameter is smaller than 1 .mu.m, the
particles are difficult to melt-knead together with resinous
components because of their too high bulk specific gravity. If the
weight-average flake diameter is greater than 40 .mu.m, the impact
resistance of molded articles and the dripping prevention effect
tend to be reduced.
[0055] The terminology "weight-average flake diameter" as used
herein for mica denotes the size of the opening of a microsieve
through which 50% by weight of particles pass in the plots on a
Rosin-Rammlar distribution, which is prepared by classifying the
particles with microsieves of various opening sizes.
[0056] These mica species can be used either individually or as a
mixture of two or more thereof different in particle size, kind,
surface treating agent, and the like.
[0057] In using talc as component (D), it is preferred to use talc
having a weight-average particle diameter of 1.0 .mu.m or more and
a bulk specific volume of 8.0 ml/g or less for obtaining enhanced
effects of addition in flame retardation and dripping prevention,
improved processability in melt kneading, and improved impact
strength of molded articles. The weight-average particle diameter
is still preferably 1.1 to 30 .mu.m, particularly 1.2 to 20 .mu.m.
The bulk specific volume is still preferably 7.0 ml/g or less,
particularly 6.0 ml/g or less. Talc having a weight-average
particle diameter of less than 1.0 .mu.m or a bulk specific volume
exceeding 8.0 ml/g is difficult to melt-knead with resinous
components and tends to produce only a poor effect in preventing
resin dripping. If the weight-average particle size exceeds 30
.mu.m, the molded article tends to have reduced impact
strength.
[0058] The terminology "weight-average particle diameter" as used
herein for talc means the size of the opening of a microsieve
through which 50% by weight of particles pass when the particles
are classified with microsieves of various opening sizes.
[0059] The talc to be used in the present invention is chosen
appropriately from commercially available products without
particular limitation in kind, place of origin, etc. The talc can
be surface-treated to have improved adhesion to the resin matrix. A
silane coupling agent containing an epoxy group, such as
epoxysilane, is a preferred surface treating agent, for it will not
reduce the physical properties of the resins. The surface treatment
can be carried out in a conventional manner with no particular
restriction. These talc species can be used either individually or
as a mixture of two or more species different in particle diameter,
kind, surface treating agent, etc.
[0060] Silicate compound (D) is added in an amount of 0.1 to 100
parts by weight, preferably 0.2 to 70 parts by weight, still
preferably 0.3 to 50 parts by weight, per 100 parts by weight of
the total amount of polycarbonate resin (A) and aromatic polyester
resin (B). Less than 0.1 part by weight of silicate compound (D)
tends to produce poor effect in improving flame retardance, heat
resistance and mechanical strength of molded articles. More than
100 parts by weight of silicate compound (D) tends to reduce the
impact resistance and surface properties of molded articles and to
be difficult to melt-knead with the resins.
[0061] For the purpose of further improving flame retardance, (E) a
fluorocarbon resin and/or silicone can be used in the present
invention.
[0062] The fluorocarbon resin is a resin containing a fluorine atom
and includes polymonofluoroethylene, polydifluoroethylene,
polytrifluoroethylene, polytetrafluoroethylene, and a
tetrafluoroethylene-hexafluoropropylene copolymer. If desired,
copolymers obtained from a monomer which provides the
above-described fluorocarbon resin and a copolymerizable monomer
can be used in such an amount that will not ruin the physical
properties of resulting molded articles such as flame retardance.
These fluorocarbon resins can be used either individually or as a
combination of two or more thereof.
[0063] The fluorine content in the fluorocarbon resin is preferably
such that corresponds to polymono- to tetrafluoroethylene.
Polytetrafluoroethylene is preferred the most of the fluorocarbon
resins.
[0064] The fluorocarbon resin preferably has a molecular weight of
1,000,000 to 20,000,000, particularly 2,000,000 to 10,000,000. The
fluorocarbon resin can be prepared by customary methods, such as
emulsion polymerization, suspension polymerization, bulk
polymerization, and solution polymerization.
[0065] The silicone is an organosiloxane, including siloxane
compounds, e.g., dimethylsiloxane and phenylmethylsiloxane, and
polyorganosiloxanes obtained by homo- or copolymerizing the
siloxane compounds, such as dimethyl polysiloxane, phenylmethyl
polysiloxane. The polyorganosiloxane may be modified silicone
having its molecular end substituted with an epoxy group, a
hydroxyl group, a carboxyl group, a mercapto group, an amino group,
an ether group, etc.
[0066] Inter alia, polymers having a number average molecular
weight of 200 or higher, particularly 1,000 to 5,000,000, are
preferred for their effect in improving flame retardance. The
silicone is not particularly limited in form and can have any of an
oil form, a rubber form, a varnish form, a powder form, a pellet
form, etc.
[0067] Fluorocarbon resin and/or silicone (E) is/are added in an
amount of 0.01 to 5 parts by weight, preferably 0.03 to 4 parts by
weight, still preferably 0.05 to 3.5 parts by weight, per 100 parts
by weight of the total amount of polycarbonate resin (A) and
thermoplastic polyester resin (B). If the amount is less than 0.01
part, the effect in improving flame retardance is small. If it
exceeds 5 parts, the moldability is reduced.
[0068] Where silicate compound (D) and fluorocarbon resin and/or
silicone (E) are added in combination, there is produced an
increased flame retardation effect so that satisfactory flame
retardance can be obtained even with the amount of stabilized red
phosphorus (C) being as small as 0.1 to 3 parts by weight. As a
result, the smell on molding is further weakened, and the cost of
production is reduced. The amount of stabilized red phosphorus (C)
to be added is preferably 0.2 to 2.8 parts by weight, still
preferably 0.3 to 2.5 parts.
[0069] In the present invention, the flame retardance and molding
processability can further be improved by adding (F) an organic
phosphorus flame retardant according to the end use and purpose.
Useful organic phosphorus flame retardants include phosphates,
phosphonates, phosphinates, phosphine oxides, phosphites,
phosphonites, phosphinites and phosphines. Specific examples are
trimethyl phosphate, triethyl phosphate, tributyl phosphate,
tri(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl
phosphate, tricresyl phosphate, trixylenyl phosphate,
tris(isopropylphenyl) phosphate, tris(phenylphenyl) phosphate,
trinaphthyl phosphate, cresyldiphenyl phosphate, xylenyldiphenyl
phosphate, diphenyl(2-ethylhexyl) phosphate,
di(isopropylphenyl)phenyl phosphate, phenyldicresyl phosphate,
di-2-ethylhexyl phosphate, monoisodecyl phosphate,
2-acryloyloxyethyl acid phosphate, 2-methacryloylxyethyl acid
phosphate, diphenyl-2-acryloyloxyethyl phosphate,
diphenyl-2-methacryloyloxyethyl phosphate, triphenyl phosphite,
trisnonylphenyl phosphite, tristridecyl phosphite, dibutyl
hydrogenphosphite, triphenylphosphine oxide, tricresylphosphine
oxide, diphenyl methanephosphonate, and diethyl
phenylphosphonate.
[0070] In particular, phosphoric esters represented by formula:
1
[0071] wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each
represent a monovalent aromatic or aliphatic group; R.sup.5
represents a divalent aromatic group; n represents a number of from
0 to 16; nR.sup.3's and nR.sup.5's may be the same or different,
respectively, are preferred for their excellent flame retardation
effect and ease of handling. Condensed phosphoric esters of the
above formula, in which n is 1 to 16, are still preferred; for they
cause less contamination of the metallic part of a mold.
[0072] Examples of the phosphoric esters of the above formula
wherein n is 0 are triphenyl phosphate, tricresyl phosphate,
trixylenyl phosphate, cresyldiphenyl phosphate, and xylenyldiphenyl
phosphate.
[0073] Examples of the condensed phosphoric esters of the above
formula are shown below.
[0074] (1) Resorcinolbis(diphenyl) phosphate 2
[0075] (2) Resorcinolbis(di-2,6-xylyl) phosphate 3
[0076] (3) Bisphenol A bis(dicresyl) phosphate 4
[0077] (b 4) Hydroquinonebis(di-2,6-xylyl) phosphate 5
[0078] (5) Condensates comprising these phosphates.
[0079] These organic phosphorus flame retardants can be used either
individually or as a combination of two or more thereof.
[0080] Organic phosphorus flame retardant (F) is added in an amount
of 0.1 to 30 parts by weight, preferably 0.2 to 25 parts by weight,
still preferably 0.3 to 20 parts by weight, per 100 parts by weight
of the total amount of polycarbonate resin (A) and aromatic
polyester resin (B). If the amount of organic phosphorus flame
retardant (F) is less than 0.1 part by weight, the effects in
improving flame retardance and molding processability are poor. If
it exceeds 30 parts by weight, the resulting molded articles tend
to have reduced impact resistance, heat resistance or solvent
resistance.
[0081] In order to improve the impact strength, toughness, chemical
resistance and the like of the molded articles, it is preferable to
add (G) one or more elastic resins selected from graft polymers and
olefin resins. Elastic resins having at least one glass transition
point at or below 0.degree. C., particularly -20.degree. C. or
lower, are preferred for improving the impact strength.
[0082] Of elastic resins (G) the graft rubber is one comprising a
rubber-like elastomer to which a vinyl monomer is
graft-copolymerized.
[0083] The rubber-like elastomers include diene rubbers, such as
polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene
rubber, and alkyl (meth)acrylate-butadiene rubber, acrylic rubber,
ethylene-propylene rubber, and siloxane rubber.
[0084] The vinyl monomer includes aromatic vinyl compounds, vinyl
cyanide compounds, alkyl (meth)acrylates, and other vinyl compounds
capable of being grafted to rubber-like elastomers.
[0085] The aromatic vinyl compounds include styrene,
o-methylstyrene, m-methylstyrene, p-methylstyrene, .alpha.
-methylstyrene, and vinyltoluene.
[0086] The vinyl cyanide compounds include acrylonitrile and
methacrylonitrile.
[0087] The alkyl (meth)acrylates include butyl acrylate, butyl
methacrylate, ethyl acrylate, ethyl methacrylate, methyl acrylate,
and methyl methacrylate.
[0088] The other vinyl compounds include unsaturated acids, such as
acrylic acid and methacrylic acid; glycidyl (meth)acrylates, such
as glycidyl acrylate and glycidyl methacrylate; vinyl acetate,
maleic anhydride, and N-phenylmaleimide.
[0089] The copolymerizing ratio of the rubber-like elastomer and
the vinyl compound is not particularly limited. A preferred ratio
for securing improvement in impact strength is 10/90 to 90/10,
particularly 30/70 to 80/20, by weight. If the weight ratio of the
rubber-like elastomer is less than 10, the effect in improving
impact resistance is lessened. If it exceeds 90, the graft rubber
tends to have reduced compatibility to resins (A) and (B).
[0090] Of elastic resin (G), the term "olefin resin" is used herein
in its inclusive sense and is intended to include not only
polyolefins in its narrow sense but also polydienes, mixtures of
two or more of the polyolefins and polydienes, copolymers
comprising an olefin monomer and two or more diene monomers,
copolymers comprising an olefin monomer and at least one vinyl
monomer copolymerizable with an olefin, and the like. Examples of
the olefin resins are homo- or copolymers comprising one or more
monomers selected from ethylene, propylene, 1-butene, 1-pentene,
isobutene, butadiene, isoprene, phenylpropadiene, cyclopentadiene,
1,5-norbornadiene, 1,3-cyclohexadiene, 1,4-cyclohexadiene,
1,5-cyclooctadiene, 1,3-cyclooctadiene,
.alpha.,.omega.-nonconjugated diene, etc.; and mixtures of two or
more of these homopolymers and copolymers. Preferred among them are
polyethylene and polypropylene from the standpoint of improvement
in chemical resistance of the resulting composition.
[0091] Copolymers comprising the above-described olefin component
and a vinyl monomer copolymerizable with the olefin, such as
(meth)acrylic acid, an alkyl (meth)acrylate, glycidyl
(meth)acrylate, vinyl acetate, maleic anhydride, N-phenylmaleimide,
and carbon monoxide, are also useful. Examples of such copolymers
are an ethylene-ethyl acrylate copolymer, an ethylene-butyl
acrylate-carbon monoxide terpolymer, an ethylene-glycidyl
methacrylate copolymer, an ethylene-glycidyl methacrylate-vinyl
acetate copolymer, an ethylene-vinyl acetate copolymer, an
ethylene-vinyl acetate-carbon monoxide copolymer, an
ethylene-acrylic acid copolymer, an ethylene-maleic anhydride
copolymer, and an ethylene-maleic anhydride-N-phenylmaleimide
copolymer.
[0092] These polyolefin resins can be obtained by various
polymerization techniques with no particular restriction. As for
polyethylene, for instance, high-density polyethylene,
medium-density polyethylene, low-density polyethylene, linear
low-density polyethylene, and the like are produced depending on
the polymerization process, any of them can be used for
preference.
[0093] When the graft polymer and the olefin resin are used in
combination as component (G), the above-mentioned various effects
are enhanced.
[0094] The amount of elastic resin (G) to be added is preferably
0.1 to 20 parts by weight, still preferably 0.1 to 15 parts by
weight, particularly preferably 0.2 to 12 parts by weight, per 100
parts by weight of the total amount of polycarbonate resin (A) and
thermoplastic polyester resin (B). If it exceeds 20 parts, rigidity
and heat resistance are reduced.
[0095] In order to further improve the heat resistance and
mechanical strength of the resin, a reinforcing filler other than
silicate compound (D) can be used either individually or in
combination with component (D). Suitable inorganic reinforcing
fillers include fibrous reinforcements, such as glass fiber, carbon
fiber, and metal fiber; calcium carbonate, glass beads, glass
powder, ceramic powder, metal powder, and carbon black. They may be
surface-treated to have increased adhesion to the resin matrix. A
silane coupling agent containing an epoxy group, such as
epoxysilane, is a preferred surface treating agent, which will not
reduce the physical properties of the resins. The surface treatment
can be carried out in a conventional manner with no particular
restriction.
[0096] Two or more reinforcing fillers different in kind, particle
diameter or length, manner of surface treatment, and the like can
be used in combination.
[0097] The amount of the inorganic reinforcing fillers to be added
is not more than 100 parts by weight, preferably not more then 50
parts by weight, still preferably 10 parts by weight or less, per
100 parts by weight of the total amount of polycarbonate resin (A)
and aromatic polyester resin (B). Addition of more than 100 parts
by weight not only results in reduction of impact resistance but
tends to reduce molding processability and flame retardance.
Moreover, as the amount of the inorganic reinforcing filler
increases, there is a tendency to deterioration in surface
properties and dimensional stability of the resulting molded
articles. Where weight is put on these properties, it is preferred
to minimize the amount of the inorganic reinforcing filler.
[0098] As long as the effects of the invention are not impaired,
the flame-retardant resin composition according to the present
invention can contain arbitrarily selected additional thermoplastic
or thermosetting resins, for example, liquid crystal polyester
resins, polyester ester elastomeric resins, polyester ether
elastomeric resins, polyolefin resins, polyamide resins,
polystyrene resins, polyphenylene sulfide resins, polyphenylene
ether resins, polyacetal resins, and polysulfone resins, used
either individually or as a combination of two or more thereof.
[0099] In order to further improve the performance of the
flame-retardant resin composition of the invention, it is preferred
to use antioxidants (e.g., phenol antioxidants and thioether
antioxidants), heat stabilizers (e.g., phosphorus type
stabilizers), and the like either individually or as a mixture of
two or more thereof. If desired, the resin composition can contain
one or more of other well-known additives, such as stabilizers,
lubricants, parting agents, plasticizers, flame retardants other
than phosphorus type compounds, flame retardation aids, ultraviolet
absorbers, light stabilizers, pigments, dyes, antistatic agents,
electric conductivity imparting agents, dispersants,
compatibilizers, antimicrobials, and so on.
[0100] The method for preparing the flame-retardant resin
composition of the invention is not particularly limited. For
example, the composition is prepared by drying the above-mentioned
components and additives, resins, etc. and melt-kneading them in a
melt-kneading machine, such as a single- or twin-screw extruder.
Where a compounding ingredient is liquid, it can be added to the
barrel of a twin-screw extruder by means of a liquid feed pump.
[0101] The method for molding the thermoplastic resin composition
prepared in the present invention is not particularly limited.
Molding methods customarily employed for thermoplastic resins, such
as injection molding, blow molding, extrusion molding, vacuum
forming, press molding, calendering, expansion molding, and the
like, can be applied.
[0102] The flame-retardant thermoplastic resin composition of the
invention is suited to a variety of uses. Preferred uses include
interior and exterior parts of appliances and office automation
equipment, injection molded parts of automobiles, blow molded
articles, extruded articles, expansion molded articles, etc.
BEST MODE FOR CARRYING OUT THE INVENTION
[0103] The present invention will now be illustrated in greater
detail by way of Examples, but it should be understood that the
present invention is not limited thereto. Unless otherwise noted,
all the parts and percents are given by weight.
[0104] Evaluations of resin compositions were made in accordance
with the following methods.
[0105] Methods of Evaluation:
[0106] After the pellets obtained were dried at 120.degree. C. for
4 hours, the dried pellets were injection molded by means of a 35t
injection molding machine at a cylinder temperature of 280.degree.
C. and a mold temperature of 70.degree. C. to prepare a bar of 12
mm in width, 127 mm in length and 1.6 mm, 2.5 mm or 6.4 mm in
thickness and a plate of 150 mm.times.150 mm.times.2.5 mm (t).
[0107] 1) Flame Retardance (1.6 mm thickness)
[0108] The flame retardance of the 1.6 mm thick bar was rated on
UL-94V Standard. An evaluation was done by judging at which of
levels V-2, V-1 and V-0 the flame retardance was.
[0109] 2) Flame Retardance (2.5 mm thickness)
[0110] The flame retardance of the 2.5 mm thick bar was rated on
UL-94V Standard. An evaluation was done by judging at which of
levels V-2, V-1 and V-0 the flame retardance was. Further, a 2.5 mm
thick bar and a 2.5 mm thick plate were prepared from those resin
compositions which were rated at V-0 in the above evaluation, and
it was judged whether flame retardance was rated at 5VA or 5VB.
[0111] 3) Heat Resistance
[0112] Heat resistance was evaluated by measuring a deflection
temperature under load on a 6.4 mm thick bar in accordance with
ASTM D-648 under a load of 0.45 MPa.
[0113] 4) Long-term Heat Stability
[0114] A 6.4 mm thick bar was treated at 150.degree. C. for 150
hours. Before and after the heat treatment, a flexural strength was
measured in accordance with ASTM D-790. A flexural strength
retention (%) was calculated from formula:
[0115] (Strength after treatment at 150.degree. C.)/(Strength
before treatment).times.100
[0116] Some samples having poor heat resistance underwent
considerable deformation on heat treating at 150.degree. C. so that
the flexural strength was unmeasurable, which are indicated
by--(hyphen) in Table 1.
[0117] 5) Smell
[0118] After being dried at 120.degree. C. for 4 hours, the pellets
were purged from the cylinder of a 75t injection molding machine at
a cylinder temperature of 300.degree. C. The smell emitted then was
evaluated organoleptically and graded as follows.
[0119] A . . . No smell
[0120] B . . . Little smell
[0121] C . . . Slight smell
[0122] D . . . Considerable smell
[0123] 6) Flowability
[0124] After the pellets were dried at 120.degree. C. for 4 hours,
a melt index (MI) was measured in accordance with JIS K6730 at
280.degree. C. under a load of 2160 g to evaluate the
flowability.
EXAMPLE 1
[0125] Seventy-five parts of a bisphenol A type polycarbonate resin
(A1) having a viscosity average molecular weight of about 22000, 25
parts of a polyethylene terephthalate resin (B1) having an
intrinsic viscosity of about 0.75 dl/g, 4 parts of Nova Excel 140
(C1) (a trade name of phenol resin-coated red phosphorus, produced
by Rin Kagaku Kogyo K.K.), and 0.3 part of Adeca Stab HP-10 (a
trade name of a phosphite type stabilizer, produced by Asahi Denka
Kogyo K.K.) were previously dry blended. The blend was fed to the
hopper of a vented twin-screw extruder with its cylinder
temperature set at 280.degree. C. (TEX 44, manufactured by The
Japan Steel Works, Ltd.) and melt-extruded to obtain a resin
compound. The results of evaluations on the resulting resin
composition are shown in Table 1.
EXAMPLES 2 TO 26
[0126] Resin compositions were prepared in the same manner as in
Example 1, except for changing the compounding ingredients as shown
in Tables 1 and 2. When the total amount of silicate compound(s)
(D) exceeded 10 parts, component (D) was added through the side
feed opening of the extruder. Of organic phosphorus flame
retardants (F), those which are liquid at room temperature were fed
to the cylinder barrel by means of a liquid feed pump. The
compounding ingredients used were as follows. The results of
evaluations are shown in Tables 1 and 2.
[0127] (A) Polycarbonate Resin
[0128] (A2) Bisphenol A type polycarbonate resin having a viscosity
average molecular weight of about 28800.
[0129] (B) Thermoplastic Polyester Resin
[0130] (B2) Polyethylene terephthalate resin having an intrinsic
viscosity of 0.6 dl/g.
[0131] (B3) Polybutylene terephthalate resin having an intrinsic
viscosity of 0.85 dl/g.
[0132] (C) Stabilized Red Phosphorus
[0133] (C2) Stabilized red phosphorus having an average particle
diameter of 20 .mu.m, having been coated with 10% of aluminum
hydroxide.
[0134] (D) Silicate Compound
[0135] (D1) Mica (A-21S, a trade name, produced by Yamaguchi Unmo
K.K.)
[0136] (D2) Talc (Microace K-1, a trade name, produced by Nippon
talc K.K.)
[0137] (E) Fluorocarbon resin and/or Silicone
[0138] (E1) Polytetrafluoroethylene (Polyfureon FA-500, a trade
name, produced by Daikin Industries, Ltd.)
[0139] (E2) Silicone (Si Powder DC4-7051, a trade name, produced by
Toray Dow Corning Silicone Co., Ltd.)
[0140] (F) Organic Phosphorus Flame Retardant
[0141] (F1) Triphenyl phosphate
[0142] (F2) Bisphenol A bis(dicresyl) phosphate
[0143] (F3) Resorcinolbis(di-2,6 -xylyl) phosphate
[0144] (F4) Hydroquinonebis(di-2,6-xylyl) phosphate
[0145] (F5) Resorcinolbis(diphenyl) phosphate
[0146] (G) Elastic Resin (selected from graft polymers and olefin
resins)
[0147] (G1) MBS resin (Kane Ace M-511, a trade name, produced by
Kanegafuchi Chemical Industry Co., Ltd.)
[0148] (G2) Linear low-density polyethylene (LLDPE) (Idemitsu
Polyethylene-L 0134N, a trade name, produced by Idemitsu
Petrochemical Co., Ltd.)
[0149] (G3) Ethylene-ethyl acrylate copolymer (Evaflex EEA A-713, a
trade name, produced by Du Pont-Mitui Polychemicals Co., Ltd.)
[0150] Other Additives
[0151] Glass fiber (T-195H/PS, a trade name, produced by Nippon
Electric Glass Co., Ltd.)
COMPARATIVE EXAMPLES 1 TO 9
[0152] Resin compositions were prepared in the same manner as in
Example 1, except for changing the compounding ingredients as shown
in Table 3 below. The results of evaluations are also shown in
Table 3.
[0153] The following resins were used as comparative resins other
than the polycarbonate resins and polyester resins. PPE Resin:
Poly(2,6-dimethyl-1,4-phenylene)ether resin having a limiting
viscosity number of 0.50 as measured in chloroform at 30.degree.
C.
[0154] HIPS Resin: Rubber-modified high impact polystyrene
(Estyrene HI H-65, a trade name, produced by Nippon Steel Chemical
Co., Ltd.)
[0155] Red Phosphorus: Untreated red phosphorus (reagent) was used
for comparison with stabilized red phosphorus.
1 TABLE 1 Example No. Resin Composition 1 2 3 4 5 6 7 8 9 10 11 12
13 14 15 A PC (A1) 75 75 75 75 75 85 75 75 75 60 80 80 75 80 PC
(A2) 75 B PET (B1) 25 25 25 25 15 25 25 25 40 20 20 25 20 PET (B2)
25 PBT (B3) 25 C Stabilized 4.0 5.0 0.7 3.0 0.7 0.4 0.7 0.6 1.0 0.5
2.0 1.5 0.3 0.2 red P (C1) Stabilized 1.0 red P (C2) D Mica (D1)
3.0 15 3.0 3.0 3.0 10 0 5 15 15 Talc (D2) 3.0 15 5 5 E PTFE (E1)
0.1 0.3 0.3 0.3 0.3 0.1 0.3 0.5 0.8 0.5 Silicone (E2) 1.0 G MBS
(G1) 1 1 1 0.5 LLDPE (G2) EEA (G3) 3 3 3 2 Others Glass fiber 5 5
HP-10 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.5 0.5
(stabilizer) Flame retardance at V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0
V-0 V-0 V-0 V-0 V-0 V-0 V-1 1.6 mm (t) (UL-94) Flame retardance at
V-0 V-0 V-0 V-0 V-0 5VB 5VB 5VB 5VB 5VA 5VA 5VA 5VA 5VA V-0 2.5 mm
(t) (UL-94) Heat resistance (.degree. C.) 144 130 139 145 139 138
135 137 138 145 146 147 145 145 147 Long-term heat 118 102 108 120
108 105 106 107 102 117 120 120 110 118 110 stability (%)
Flowability (g/10 min) 15 15 14 8 14 11 11 12 14 9 7 7 7 8 6 Smell
B B A A A A A A A A A A A A A
[0156]
2 TABLE 2 Example No. Resin Composition 16 17 18 19 20 21 22 23 24
25 26 A PC (A1) 90 85 90 80 90 90 80 PC (A2) 85 70 85 75 B PET (B1)
10 10 20 10 15 10 20 PET (B2) 15 30 25 PBT (B3) 15 C Stabilized red
P (C1) 1 1 0.8 1 1.5 2.5 1 1 0.6 1 1.5 D Mica (D1) 3.0 3.0 3.0 3.0
3.0 3.0 3.0 15 10 10 Talc (D2) 5 E PTFE (E1) 0.5 0.5 0.5 0.5 0.5
0.5 0.2 0.5 0.5 0.2 F Phosphorus compound (F1) 6 Phosphorus
compound (F2) 5 4 4 6 5 5 7 Phosphorus compound (F3) 6 Phosphorus
compound (F4) 4 Phosphorus compound (F5) 6 Others HP-10
(stabilizer) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Flame
retardance at 1.6 mm (t) V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0
V-0 (UL-94) Flame retardance at 2.5 mm (t) V-0 5VB 5VB 5VB 5VB 5VB
5VB 5VB 5VA 5VA 5VA (UL-94) Heat resistance (.degree. C.) 118 121
123 122 121 119 120 118 133 133 131 Long-term heat stability (%) 85
99 95 91 99 93 92 94 98 106 103 Flowability (g/10 min) 18 18 19 17
20 23 18 19 10 14 13 Smell A A A A A A A A A A A
[0157]
3 TABLE 3 Comparative Example No. Ref. Resin Composition 1 2 3* 4 5
6 7 8 9 Ex. 1 A PC (A1) 100 100 75 75 60 75 70 B PET (B1) 100 25 25
40 25 30 Other PPE 25 25 resins HIPS 75 75 C Stabilized red P 4.0
2.0 5.0 15.0 6.0 (C1) Untreated red P 0.6 D Talc (D2) 15 3.0 E PTFE
(E1) 0.1 0.1 0.1 0.1 0.1 0.3 0.2 0.2 0.2 F Phosphorus 5.5 compound
(F5) G MBS (G1) 1 5 EEA (G3) 2 3 Others Stabilizer (HP-10) 0.3 0.3
0.3 0.3 0.3 0.3 0.3 Glass fiber 50 Flame retardance at 1.6 mm V-0
V-0 V-1 V-0 not not V V-0 V-0 not V not V (t) (UL-94) V** Flame
retardance at 2.5 mm V-0 V-0 V-1 5VA not V not V V-0 V-0 V-0 V-0
(t) (UL-94) Heat resistance (.degree. C.) 136 135 220 140 135 138
137 110 105 108 Long-term heat stability (%) -- -- 100 113 95 93 98
-- -- -- Flowability (g/10 min) 5 4 8 10 15 7 14 22 15 18 Smell B A
B D A A D B D A Note: *Only the specimens of Comparative Example 3
were prepared at a mold temperature of 130.degree. C. **"not V" in
the "flame retardance" means out of the specifications of UL 94V
Standard.
[0158] Containing no polyester resin, Comparative Examples 1 and 2
have poor flowability and enjoy no improvements in long-term heat
stability and heat resistance even with addition of red phosphorus.
Comparative Example 3, which contains no polycarbonate resin, is
inferior in flame retardance. Comparative Example 4 gives off smell
on account of the presence of a large amount of stabilized red
phosphorus. Comparative Examples 5 and 6 have poor flame retardance
in the absence of stabilized red phosphorus. Besides, Comparative
Examples 5 and 6 are inferior to Examples 5 and 10, respectively,
in heat resistance and long-term heat stability. Comparative
Example 7 produces smell because of the use of non-stabilized red
phosphorus. Only using the organic phosphorus flame retardant,
Comparative Example 8 exhibits poor heat resistance and poor
long-term heat stability. Compared with Reference Example 1,
Comparative Example 9 shows no improvements in flame retardance,
heat resistance, and long-term heat stability in spite of the
addition of stabilized red phosphorus. This proves that the effects
of stabilized red phosphorus on these characteristics can never be
manifested except when added to specific resins.
[0159] As is clear from the foregoing, it is seen that all the
compositions according to the present invention are excellent in
heat resistance, long-term heat stability, flame retardance and
freedom from smell as well as flowability in molding. It is also
seen that these effects cannot be obtained when stabilized red
phosphorus is added to resins other than those specified in the
present invention.
[0160] Industrial Applicability
[0161] The present invention provides a flame-retardant resin
composition exhibiting excellent characteristics in flowability in
molding, heat resistance, long-term heat stability, flame
retardance, and smell, which are of great use in industry.
* * * * *