U.S. patent application number 09/403490 was filed with the patent office on 2002-09-12 for fire-retardant resin compositions.
Invention is credited to HARUHARA, JUN, HIRONAKA, KATSUHIKO, SUZUKI, MIOKO.
Application Number | 20020128365 09/403490 |
Document ID | / |
Family ID | 26379739 |
Filed Date | 2002-09-12 |
United States Patent
Application |
20020128365 |
Kind Code |
A1 |
SUZUKI, MIOKO ; et
al. |
September 12, 2002 |
FIRE-RETARDANT RESIN COMPOSITIONS
Abstract
To provide a resin composition as a non-halogenated flame
retardant resin composition, having a. high degree of flame
retardant property, equipped with good electric characteristics by
suppressing the generation of phosphoric acid, and improved in
working environment and safety by using a flame retardant resin
composition comprising (A) a thermoplastic aromatic polyester of
100 parts weight, (B) a coated red phosphorus powder consisting of
an essentially spherical red phosphorus having a cured resin
coating, directly obtained from a conversion treatment method of
yellow phosphorus, not requiring a pulverization and without having
crushed surfaces of 1 to 15 parts weight and (C) an aromatic
polycarbonate of 5 to 150 parts weight.
Inventors: |
SUZUKI, MIOKO; (CHIBA,
JP) ; HIRONAKA, KATSUHIKO; (CHIBA, JP) ;
HARUHARA, JUN; (CHIBA, JP) |
Correspondence
Address: |
SUGHRUE MION ZINN MACPEAK & SEAS
2100 PENNSYLVANIA AVENUE NW
WASHINGTON
DC
20037
|
Family ID: |
26379739 |
Appl. No.: |
09/403490 |
Filed: |
October 22, 1999 |
PCT Filed: |
February 23, 1999 |
PCT NO: |
PCT/JP99/00790 |
Current U.S.
Class: |
524/414 ;
523/210 |
Current CPC
Class: |
C08L 69/00 20130101;
C08L 67/02 20130101; C08K 9/08 20130101; C08L 67/02 20130101; C08K
9/08 20130101; C08L 67/02 20130101 |
Class at
Publication: |
524/414 ;
523/210 |
International
Class: |
C08K 005/49; C08K
009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 1998 |
JP |
10-40286 |
Oct 6, 1998 |
JP |
10-284008 |
Claims
1. A flame retardant resin composition comprising (A) a
thermoplastic aromatic polyester of 100 parts weight, (B) a coated
red phosphorus powder composed of essentially spherical red
phosphorus, having a cured resin coating, directly obtained by a
conversion treatment method of yellow phosphorus, not requiring the
pulverization thereof and without having crushed surfaces of 1 to
15 parts weight and (C) an aromatic polycarbonate of 5 to 150 parts
weight.
2. A flame retardant resin composition according to claim 1,
wherein (D) at least one kind of a compound selected from a group
consisting of titanium oxide, aluminum oxide and molybdenum sulfide
is further contained in a range of 0.05 to 5 parts weight based on
100 parts weight of (A) the thermoplastic aromatic polyester.
3. A flame retardant resin composition according to claim 2,
wherein the generated amount of phosphine after heating the
composition at a temperature of 120.degree. C. for 24 hours is not
more than 5.times.10.sup.-5 g based on 1 g of red phosphorus
contained in the composition, and also the generated amount of
phosphoric acid by maintaining the composition under a humid heat
condition at a temperature of 121.degree. C., at a humidity of 100%
RH and under a pressure of 2.1 atm. is not more than
3.times.10.sup.-4 g based on 1 g of the red phosphorus contained in
the composition.
4. A flame retardant resin composition according to claim 1,
wherein (A) the thermoplastic aromatic polyester is a polyester
comprising ethylene terephthalate, trimethylen,e terephthalate,
tetramethylene terephthalate, or tetramethylene-2,6-naphthalene
dicarboxylate as a main recurring unit.
5. A flame retardant resin composition according to claim 1,
wherein the cured resin coating of (B) the coated red phosphorus
powder, consists essentially of at least one kind of the cured
material of a curable resin selected from a group consisting of a
phenolic resin, an epoxy resin, an unsaturated polyester resin, a
melamine resin, a urea resin and an aniline resin.
6. A flame retardant resin composition according to claim 1,
wherein at least one kind of an inorganic compound selected from a
group consisting of aluminum hydroxide, magnesium hydroxide, zinc
hydroxide and titanium hydroxide, is dispersed and contained in the
cured resin coating of (B) the coated red phosphorus powder.
7. A flame retardant resin composition according to claim 5,
wherein under the cured resin coating of (B) the coated red
phosphorus powder, a coating consisting of at least one kind of an
inorganic compound selected from a group consisting of aluminum
hydroxide, magnesium hydroxide, zinc hydroxide and titanium
hydroxide is further present by making a contact with the red
phosphorus.
8. A flame retardant resin composition according to claim 1,
wherein the mean particle diameter of (B) the coated red phosphorus
powder, is in a range of 5 to 40 .mu.m.
9. A flame retardant resin composition according to claim 1,
wherein (C) the aromatic polycarbonate is an aromatic polycarbonate
having a viscosity-averaged molecular weight of 20,000 to
25,000.
10. A flame retardant resin composition according to claim 1,
wherein an inorganic filler is further contained in a range of 5 to
150 parts weight based on 100 parts weight of (A) the thermoplastic
aromatic polyester.
11. A flame retardant resin composition according to claim 1,
wherein a fluorine resin is further contained in a range of 0.01 to
10 parts weight based on 100 parts weight of (A) the thermoplastic
aromatic polyester.
12. A flame retardant resin composition according to claim 1,
wherein (B) the coated red phosphorus powder and (C) the aromatic
polycarbonate are melted and kneaded beforehand.
13. A flame retardant resin composition used for an
electric/electronic part, consisting of the flame retardant resin
composition according to claim 1.
14. An electric/electronic part being molded from the flame
retardant resin composition according to claim 1.
Description
TECHNICAL FIELD
[0001] The present invention relates to a flame retardant resin
composition having a high degree of flame retardant property. More
particularly the present invention relates to a non-halogenated
flame retardant resin composition improved in working environment
and safety, reducing the generation of phosphoric acid and
excellent in electric characteristics.
BACKGROUND ART
[0002] The polyester such as a polybutylene terephthalate, etc.,
has excellent mechanical characteristics, heat resistance, chemical
resistance, etc., and is widely used as molded articles for uses in
an electric/electronic field, automobile field, etc.
[0003] For the molded articles used in these fields, the flame
retardant properties are required in many cases. Nowadays, resin
compositions using mainly a halogenated compound and an antimony
compound as a flame retardant and a flame retardant assistant for
imparting the flame retardant property thereto, are generally
used.
[0004] However, since in the case of using a resin composition
containing a halogenated flame retardant as a molded article
constituting an electric appliance, sometimes a decomposition
product thereof may corrode a metal part which is another element
constituting the electric appliance, a non-halogenated flame
retardant resin composition has been required. Also, since some
halogenated flame retardants cause issues in environmental effects,
the non-halogenated flame retardant resin composition is further
required.
[0005] As the non-halogenated flame retardant, there are phosphorus
compounds. As a representative organic phosphorus compound, a low
molecular weight phosphate such as triphenylphosphate (TPP), has
been frequently used so far. However, since the polyester such as
the polybutylene terephthalate, requires a relatively high
processing temperature, there were problems of a bleeding and
insufficient heat resistance in the case of blending the low
molecular weight phosphate.
[0006] In the Japanese unexamined patent publication 7-126498
(Unexamined publication on May 16, 1995, Applied on Nov. 8, 1993 as
the Japanese patent application 5-278015), a non-halogenated flame
retardant for the polyester resin obtained by melting for reacting
a polyester-based resin, an epoxy compound having 2 or more epoxy
groups in its molecule, a phenolic resin and/or one or more kinds
of non-halogenated flame retardant compounds selected from
phosphorus-, nitrogen- and boron-based compounds having a
functional group capable of reacting with the epoxy group, was
disclosed. And in The Japanese unexamined patent publication
7-278267 (Unexamined publication on Oct. 24, 1995, Applied on Apr.
7, 1994 as the Japanese patent application 6-69728), a flame
retardant polyester-based resin composition obtained by blending 5
to 50 parts weight above non-halogenated flame retardant with 100
parts weight of a polyester, was disclosed. The above
non-halogenated flame retardant is characterized in using an epoxy
compound having 2 or more epoxy groups in molecule thereof .
[0007] In the Japanese unexamined patent publication 8-188717
(Unexamined publication on Jul. 23, 1996, Applied on Jan. 6, 1995
as the Japanese patent application 7-785), a flame retardant resin
composition consisting of a thermoplastic resin such as a
polystyrene and a polyester, a phosphorus compound such as a
phosphate and a phosphite, and a phenolaralkyl resin such as a
reaction product of a phenolic resin (for example; cresol) with an
aralkylhalide (for example; .alpha.,.alpha. -dichloro-p-xylene),
was disclosed.
[0008] In the Japanese unexamined patent publication 8-208884
(Unexamined publication on Aug. 13, 1996, Applied on Jan. 30, 1995
as the Japanese patent application 7-12825), a flame retardant
resin composition consisting of a thermoplastic resin such as a
polystyrene and a polyester, a phosphorus compound such as a
phosphate and a phosphite, and a phenolic resin prepared from a
phenol substituted at the ortho- or para-position, was
disclosed.
[0009] While, red phosphorus among the phosphorus compounds, is
known to exhibit an excellent flame retardant property even by
adding a small amount. As the flame retardants using the red
phosphorus, the following examples can be cited.
[0010] In the Journal of Flame Retardant Chemistry, volume 7,
69-76, 1980, it was disclosed that a polystyrene is made of flame
retardant by red phosphorus and a phenolic resin.
[0011] In the Plastic Engineering, Nov. 29-31, 1993, it was
disclosed that a polybutylene terephtahlate is made of flame
retardant by red phosphorus and a phenolic resin.
[0012] In the Japanese patent publication 2-37370 (Unexamined
patent publication 58-108248 on Jul. 28, 1983, Applied on Dec. 19,
1981 as the Japanese patent application 56-205812), a flame
retardant polyester resin composition composed of a thermoplastic
polyester having a softening point of 150.degree. C. or higher such
as a polyethylene terephthalate of 99 to 34 parts weight, red
phosphorus coated with a thermosetting resin of 1 to 25 parts
weight and a reinforcing filler of 10 to 55 parts weight, was
disclosed.
[0013] A technology of adding a metal oxide for the purpose of
inactivating red phosphorus, was disclosed in the Japanese
unexamined patent publication 51-42746 (Unexamined publication on
Apr. 12, 1976, Applied on Oct. 9, 1974 as the Japanese patent
application 49-115670), the Japanese unexamined patent publication
51-150553 (Unexamined publication on Dec. 24, 1976, Applied on Jul.
9, 1976 as the Japanese patent application 51-67544), etc.
Disclosure of the Invention
[0014] The object of the present invention is to provide a
non-halogenated flame retardant resin composition having a high
flame retardant property, improved in working environment and
safety, also reducing the generation of phosphoric acid which
affects electric characteristics thereof and excellent in electric
characteristics.
[0015] Another object of the present invention is to provide a
resin composition for electric/electronic parts consisting of a
non-halogenated resin composition having a high flame retardant
property and excellent in electric characteristics, and also
electric/electronic parts composed thereof.
[0016] Further objectives and advantages of the present invention
will be clarified by the following explanation.
[0017] The present invention comprises the following
constitution.
[0018] 1. A flame retardant resin composition comprising (A) a
thermoplastic aromatic polyester of 100 parts weight, (B) a coated
red phosphorus powder composed of essentially spherical red
phosphorus, having a cured resin coating, directly obtained by a
conversion treatment method of yellow phosphorus, not requiring the
pulverization and without having crushed surfaces of 1 to 15 parts
weight and (C) an aromatic polycarbonate of 5 to 150 parts
weight.
[0019] 2. A flame retardant resin composition according to
paragraph 1, wherein (D) at least one kind of a compound selected
from a group consisting of titanium oxide, aluminum oxide and
molybdenum sulfide is further contained in a range of 0.05 to 5
parts weight based on 100 parts weight of (A) the thermoplastic
aromatic polyester.
[0020] 3. A flame retardant resin composition according to
paragraph 2, wherein a generated amount of phosphine after heating
the composition at a temperature of 120.degree. C. for 24 hours is
not more than 5.times.10.sup.-5 g based on 1 g of red phosphorus
contained in the composition, and also the generated amount of
phosphoric acid by maintaining the composition under a humid and
heat condition at a temperature of 121.degree. C., at a humidity of
100% RH and under a pressure of 2.1 atm., is not more than
3.times.10.sup.-4 g based on 1 g of the red phosphorus contained in
the composition.
[0021] 4. A flame retardant resin composition according to
paragraph 1, wherein an inorganic filler is further contained in a
range of 5 to 150 parts weight based on 100 parts weight of (A) the
thermoplastic aromatic polyester.
[0022] 5. A flame retardant resin composition according to
paragraph 1, wherein a fluorine resin is further contained in a
range of 0.01 to 10 parts weight based on 100 parts weight of (A)
the thermoplastic aromatic polyester.
[0023] 6. A flame retardant resin composition according to
paragraph 1, wherein (B) the coated red phosphorus powder and (C)
the aromatic polycarbonate are melted and kneaded beforehand.
[0024] The present invention is explained in detail as follows.
[0025] <Thermoplastic Aromatic Polyester>
[0026] The thermoplastic aromatic polyester (A) is a polyester
consisting of an aromatic dicarboxylic acid as a main dicarboxylic
acid component and an aliphatic diol having a carbon number of 2 to
10 as a main diol component. It contains preferably 80 mole % or
more , more preferably 90 mole % or more of the aromatic
dicarboxylic acid component based on the total dicarboxylic acid
components, and also contains preferably 80 mole % or more, more
preferably 90 mole % or more of the aliphatic diol component having
the carbon number of 2 to 10 based on the total diol
components.
[0027] As the aromatic dicarboxylic acid, for example, terephthalic
acid, isophthalic acid, phthalic acid, methyl terephthalate, methyl
isophthalate, and 2,6-naphthalene dicarboxylic acid can be cited.
They can be used either by one kind, or by two or more kinds
simultaneously.
[0028] As the dicarboxylic acid component which can be used as a
copolymerization component with the aromatic dicarboxylic acid, for
example, an aliphatic or an alicyclic dicarboxylic acid such as
adipic acid, sebacic acid, decane dicarboxylic acid, azelaic acid,
dodecane dicarboxylic acid, cyclohexane dicarboxylic acid, etc.,
can be cited.
[0029] As the aliphatic diol having the carbon number of 2 to 10,
for example an aliphatic diol such as ethylene glycol, trimethylene
glycol, tetramethylene glycol, hexamethylene glycol, neopentyl
glycol, etc., and an alicyclic diol such as 1, 4-cyclohexane
dimethanol, etc., can be cited. These aliphatic diols and alicyclic
diols c(an be used either by one kind or by two or more kinds
simultaneously. As the diol component which can be used as the
copolymerization component with the aliphatic diols having the
carbon number of 2 to 10, for example,
p,p'-dihydroxyethoxybisphenol A and a polyoxyethylene glycol can be
cited.
[0030] Among them, as the thermoplastic aromatic polyester (A), the
thermoplastic aromatic polyester composed of an ester unit in which
the main dicarboxylic acid component is at least one dicarboxylic
acid selected from group consisting of terephthalic acid and
2,6-naphthalene dicarboxylic acid, and the main diol component is
at least one kind of diol selected from a group of ethylene glycol,
trimethylene -glycol and tetramethylene glycol, is preferable.
[0031] Especially, a polyester composed of a main recurring unit
consisting of ethylene terephthalate, trimethylene terephthalate,
tetramethylene terephthalate or tetramethylene-2,6-naphthalene
dicarboxylate, is preferable. Also, a polyester elastomer
consisting of these recurring unit as a main recurring unit of a
hard segment thereof, can be used.
[0032] As the above polyester elastomer, an elastomer having
tetramethylene terephthalate or tetramethylene-2,6-naphthalene
dicarboxylate as a main recurring unit of its hard segment, is
preferable. The polyester elastomer is constituted by a soft
segment and the above hard segment, and as the soft segment, for
example, a polyester elastomer composed of a dicarboxylic acid
component consisting of one or more kinds selected from a group
consisting of terephthalic acid, isophthalic acid, sebacic acid and
adipic acid, and a diol component composed of one or more kinds
selected from a group consisting of a long chain diol having carbon
number of 5 to 10 and H(OCH.sub.2CH.sub.2).sub.i- OH (i=2-5), and
also having a melting point of 100.degree. C. or lower, or being
amorphous, or a polycaprolactone can be used.
[0033] Further, the main component means a component occupying 80
mole % or more, preferably 90 mole % or more of the total
dicarboxylic acid components or the total diol components, and the
main recurring unit means a recurring unit occupying 80 mole % or
more, preferably 90 mole % or more of the total recurring
units.
[0034] The thermoplastic aromatic polyester (A) has an intrinsic
viscosity measured at 35.degree. C. in ortho-chlorophenol, of
preferably 0.5 to 1.4 dl/g, more preferably 0.6 to 1.2 dl/g. The
intrinsic viscosity of less than 0.5 is not preferable since the
mechanical strength of the obtained composition is reduced, and the
viscosity exceeding 1.4, is also not preferable, since the flowing
property, etc., of the obtained composition are reduced.
[0035] 21 Coated Red Phosphorus Powder>
[0036] In the present invention, a coated red phosphorus powder
(B), consisting essentially of a spherical red phosphorus having a
cured resin coating, not requiring a pulverization, directly
obtained from a yellow phosphorus conversion treatment method and
without having crushed surfaces, is used.
[0037] If red phosphorus without having the coating is used, there
is a risk of an ignition and a generation of phosphine caused by a
high temperature, a mechanical shock, etc.
[0038] The coated red phosphorus powder (B) is essentially a
spherical-shaped red phosphorus without having crushed surfaces,
and obtained by the conversion treating method of yellow
phosphorus. By using such essentially spherical red phosphorus, the
surfaces thereof are extremely stabilized, the stability of the red
phosphorus is increased and the stability of the composition is
improved. On the other hand, in the case of using a red phosphorus
other than the above essentially spherical red phosphorus, i.e., a
red phosphorus obtained as a lump-shaped material by heat-treating
yellow phosphorus in a reaction vessel, so-called a conversion pot,
for several days and then crushing in a crushing process, there are
following problems. That is, since many active points are formed on
the surface of the red phosphorus by the crushing, the red
phosphorus is liable to react with oxygen or a water molecule and
becomes a cause of the ignition and the generation of phosphine and
oxide.
[0039] As the method for producing the essentially spherical red
phosphorus of the coated red phosphorus powder (B), the following
method is cited. That is, yellow phosphorus is heated at a
temperature in the vicinity of the boiling point thereof in a
hermetically closed vessel substituted with an inert gas to
initiate a conversion reaction to red phosphorus. And then, the
reaction is stopped when the conversion rate or the particle
diameter attains a desired level, and the unconverted yellow
phosphorus is distilled off. By this method, an amorphous red
phosphorus composed of fine essentially spherical-shaped particles
or associates thereof, totally not requiring a pulverization, is
obtained. The conversion rate and the particle diameter of the red
phosphorus can be adjusted by a reaction time and a reaction
temperature. The preferable reaction temperature is 250 to
350.degree. C. and the preferable conversion rate is 60% or
less.
[0040] The cured resin coating on the coated red phosphorus powder
(B) consists preferably of at least one kind of the cured resin
selected from a group of a phenolic resin, an epoxy resin, an
unsaturated polyester resin, a melamine resin, a urea resin and an
aniline resin.
[0041] The coated red phosphorus powder (B) is preferably further
contains by dispersing at least one kind of inorganic compound
selected from a group consisting of aluminum hydroxide, magnesium
hydroxide, zinc hydroxide and titanium hydroxide in the cured resin
coating.
[0042] These inorganic compounds can be further contained under the
above cured resin coating by making a contact with the red
phosphorus. That is, under the cured resin coating of the coated
red phosphorus powder (B), a coating consisting of at least one
kind of the inorganic compound selected from a group consisting of
aluminum hydroxide, magnesium hydroxide, zinc hydroxide and
titanium hydroxide, and making a contact with the red phosphorus,
is allowed to be present.
[0043] The mean particle diameter of the coated red phosphorus
powder (B), is preferably in a range of 5 to 40 .mu.m, more
preferably in the range of 25 to 35 .mu.m. If the mean particle
diameter is less than 5 .mu.m, it is not preferable in a view of a
dispersion uniformity, and if it exceeds 40 .mu.m, it is also not
preferable since the mechanical characteristics and flame retardant
property are reduced.
[0044] The coated red phosphorus powder (B) is blended so as to
become in a range of 1 to 15 parts weight based on the
thermoplastic aromatic polyester (A). If the blended amount is less
than 1 part weight, the flame retardant property becomes
insufficient, and if it exceeds 15 parts weight, the mechanical
characteristics of the molded articles obtained from the flame
retardant resin composition is reduced.
[0045] The coated red phosphorus powder (B) is preferably used as
master pellets prepared previously by melting and kneading with the
aromatic polycarbonate (C). As the aromatic: polycarbonate (C), an
aromatic polycarbonate having a viscosity-averaged molecular weight
of 20,000 to 25,000, is preferable. If the viscosity-averaged
molecular weight is less than 20,000, the flame retardant property
is reduced, and if it exceeds 25,000, it is not preferable since
the flowing property is reduced to reduce its molding property.
[0046] It is possible to obtain a resin composition capable of
obtaining a molded article excellent in mechanical property by
using the coated red phosphorus powder (B) as master pellets
prepared in advance by melting and kneading with the aromatic
polycarbonate (C) in making the molded articles. Since the safety
is improved, it is desirable to use the above red phosphorus as the
master pellets.
[0047] By blending the master pellets prepared by mixing and
kneading the coated red phosphorus powder (B) with the aromatic
polycarbonate (C) in advance, with the thermoplastic aromatic
polyester (A), the flame retardant property of the composition is
markedly improved in comparison with the case of preparing master
pellets of the coated red phosphorus powder (B) with a
thermoplastic resin other than the aromatic polycarbonate and
blending the obtained master pellets with the thermoplastic
aromatic polyester (A) together with the aromatic
polycarbonate.
[0048] The content of the coated red phosphorus powder (B) in the
master pellets, is preferably 10 to 15 weight % based on the total
weight of the master pellets. If the content is less than 10 weight
%, it is not preferable since the amount of the master pellets to
be added, is increased since the efficiency of the flame retardant
is relatively reduced, and if the content exceeds 15 weight %, it
is also not preferable since it is difficult to prepare the master
pellets and also the safety is reduced.
[0049] <Aromatic Polycarbonate>
[0050] The aromatic polycarbonate (C) is usually obtained by
reacting a divalent phenol with a carbonate precursor by a solution
method or a melting method.
[0051] As the divalent phenol, for example, 2,
2-bis(4-hydroxyphenyl)-prop- ane (hereinafter may be abbreviated as
bisphenol A), 1, 1-bis (4-hydroxyphenyl) ethane, 2, 2-bis
(4-hydroxy-3-methylphenyl)propane, bis (4-hydroxyphenyl) sulfone,
etc., are cited. A bis (4-hydroxyphenyl)alkane is preferable, and
among them bisphenol A is especially preferable. The divalent
phenol can be either used singly or by mixing 2 or more kinds of
them.
[0052] As the carbonate precursor, for example, a carbonyl halide,
a carbonate or a haloformate can be cited. As a representative
example, phosgene, diphenyl carbonate, a dihalo:formate of a
divalent phenol and their mixtures are cited. In the production of
the aromatic polycarbonate, a suitable molecular weight adjusting
agent, branching agent, catalyst, etc., can be used.
[0053] The aromatic polycarbonate (C) having 20,000 to 25,000
molecular weight expressed by a viscosity-averaged molecular
weight, is preferable. If the molecular weight is less than 20,000,
the mechanical strength is reduced and also the flame retardant
property is reduced, and if it exceeds 25,000, then the flowing
property, etc., are reduced.
[0054] The aromatic polycarbonate (C) blended so as to be in a
range of 5 to 150 parts weight, based on the thermoplastic aromatic
polyester (A) of 100 parts weight. If the amount is less than 5
parts weight , the flame retardant property is insufficient and if
it exceeds 150 parts weight, the mechanical characteristics of the
obtained molded article are reduced.
[0055] <Titanium Oxide, Aluminum Oxide and Molybdenum
Sulfide>
[0056] It is preferable for the flame retardant resin composition
in the present invention to contain at least one kind of compound
(D) selected from a group consisting of titanium oxide, aluminum
oxide and molybdenum sulfide. By blending the above component
(hereinafter may be called as the (D) component), the essentially
spherical red phosphorus in the composition is markedly stabilized
and the amount of phosphine generation can be widely reduced.
[0057] Such effect as the stabilization of the essentially
spherical red phosphorus and the reduction of the phosphine
generation can be achieved by adding the titanium oxide, aluminum
oxide, molybdenum sulfide or copper oxide, but in the case of
blending copper oxide, it is not preferable since copper oxide
reacts with the essentially spherical red phosphorus to form
phosphoric acid to damage the electric characteristic thereof.
[0058] The adding amount of the above mentioned (D) component is
preferably 0.05 to 5 parts weight based on the thermoplastic
aromatic polyester (A) of 100 parts weight. If the amount is less
than 0.05 parts weight, it is not preferable since the stabilizing
effect for red phosphorus is small and if it exceeds 5 parts
weight, it is also not preferable since the mechanical
characteristics of the molded article obtained from the resin
composition are reduced.
[0059] By blending the above (D) component with the thermoplastic
aromatic polyester (A), the coated red phosphorus powder (B) and
the aromatic polycarbonate (C) in the above amount, it is possible
to obtain a flame retardant resin composition exhibiting the
phosphine generating amount after heating at 120.degree. C. for 24
hour of 5 .times.10.sup.-5 g or less based on 1 g of red phosphorus
contained in the flame retardant resin composition, and the
phosphoric acid generating amount under a humid heat condition at
121.degree. C. temperature, at 100% RH and under 2.1 atm. of
3.times.10-4 or less based on 1 g of red phosphorus contained in
the flame retardant resin composition. In this case, since the
stability of the essentially spherical red phosphorus is increased,
and also the increase of the phosphoric acid production does not
occur, bad effects to electric characteristics are extremely small
and a resin composition equipped with good electric characteristics
can be obtained.
[0060] <Additive>
[0061] It is possible for the flame retardant resin composition in
the present invention to further contain an inorganic filler in a
range not harming the object of the present invention.
[0062] As the inorganic filler, for example, a particle state or an
amorphous inorganic filler such as calcium carbonate, titanium
oxide, a feldspar-based mineral, a clay, a white carbon, a carbon
black, glass beads, a silica, etc., a scaly inorganic filler such
as a kaolin clay and a talc, and a fibrous inorganic filler such as
a glass fiber, a wollastonite, potassium titanate, aluminum borate,
a carbon fiber, an aramid fiber, etc., can be cited. When the
inorganic filler is contained, it is preferable to contain the same
in a range of 5 to 150 parts weight based on the thermoplastic
aromatic polyester (A) of 100 parts weight.
[0063] The flame retardant resin composition in the present
invention can also contain a flame retardant property-modifying
agent. As the flame retardant property-modifying agent, a fluorine
resin is preferable, and as the fluorine resin, a
polytetrafluoroethylene is cited as an example. In the case of
containing the fluorine resin, it is preferable to contain 0.01 to
10 parts weight of the same based on the thermoplastic aromatic
polyester (A) of 100 parts weight.
[0064] The flame retardant resin composition in the present
invention can contain an additive such as an antioxidant, a heat
stabilizing agent, an ultraviolet rays-absorbing agent, a
lubricant, a nucleating agent, a releasing agent, a pigment, an
impact resistance-improving agent such as various elastomers,
etc.,
[0065] The fire retarding resin composition in the present
invention can also contain the oxide or hydroxide of zinc,
aluminum, magnesium and titanium as a stabilizer of red phosphorus.
<Production method>
[0066] The flame retardant resin composition in the present
invention can be produced by a method of melting and kneading
master pellets of the coated red phosphorus powder (B) with the
aromatic polycarbonate (C), the thermoplastic aromatic polyester
(A), and the inorganic filler and the other additive as necessary
simultaneously by using, for example, an extruder.
[0067] The coated red phosphorus powder (B) and the aromatic
polycarbonate (C) are preferably melted and kneaded in advance. By
using thus obtained master pellets of the coated red phosphorus
powder (B) with the aromatic polycarbonate (C), it is possible to
obtain the flame retardant resin composition, wherein the generated
amount of phosphine after heating at 120.degree. C. for 24 hours is
5.times.10.sup.-5 g or less based on 1 g of red phosphorus
contained in the composition, and the produced amount of phosphoric
acid under a humid heat condition at 121.degree. C., at 100% RH and
under 2.1 atm is 3.times.10.sup.-4 g or less based on 1 g of red
phosphorus contained in the composition.
[0068] The inorganic filler and the other additives may be melted
and kneaded in advance with the thermoplastic polyester (A) or the
aromatic polycarbonate (C).
[0069] The resin composition obtained by melting and kneading in
the extruder, is usually cut as a pellet shape by a pelletizer, and
then can be molded to obtain a molded article.
[0070] As the method for molding, an injection molding and a blow
molding can be exemplified.
[0071] The flame retardant composition in the present invention is
suitable as the flame retardant resin composition for
electric/electronic parts, and suitably used as molded parts used
in the electric/electronic uses such as a home electric appliance,
an OA instrument, etc., by molding as the electric/electronic
parts.
[0072] Also, the flame retardant resin composition in the present
invention can be used in automobile uses. More concretely, for
example, it can be used as a switch part, a motor part, an ignition
coil case, a coil bobbin, a connector, a relay case and a fuse
case.
EXAMPLES
[0073] The present invention is explained further in detail by
following examples.
[0074] Evaluation of Characteristics
[0075] The evaluations of the characteristics of the composition
were performed by the following evaluation methods.
[0076] (1) Intrinsic viscosity
[0077] The viscosity was measured at 35C. by using
ortho-chlorophenol as a solvent.
[0078] (2) Flame retardant property
[0079] According to the vertical burning test of the UL94 standard,
the flame retardant property was evaluated by using an test piece
having a thickness of 0.8 mm. The flame retardant properties were
classified in 4 kinds as V-0, V-1, V-2 and HB in accordance with
the evaluation method described in the UL94.
[0080] (3) The amount of phosphine generation
[0081] By putting the pellets of 10 g prepared by the above method
in a glass bottle with a lid, a heat-treatment was conducted at
120.degree. C. for 24 hours in a state of closing the lid. After
cooling with air at a room temperature for 5 hours, the
concentration of phosphine in the glass bottle was measured, and
the generated amount of phosphine based on 1 g of red phosphorus
contained in the pellets was calculated by dividing the obtained
value with the amount of red phosphorus contained in the pellet.
Further, the phosphine concentration was measured by using a gas
detector tube for phosphine made by Gastech Co., Ltd.
[0082] (4) The amount of phosphoric acid generation
[0083] A flat plate having a size of 25 mm.times.25 mm.times.1 mm
thickness was molded by using an injection molding machine (made by
FANUK, Ltd.) having a locking force of 15 tons, and the molded
article was subjected to a humid heat treatment under a temperature
of 121.degree. C., at 100% RH and under 2.1 atm. for 200 hours.
After cooling with air at a room temperature for 24 hours, the
deposited material on the surface of the molded articles was
dissolved with a pure water of 5 ml, the concentrations of
phosphoric acid and phosphorous acid were measured by using an ion
chromatograph (type DX-100 made by DIONEX K.K.) and the generated
amount of phosphoric acid based on 1 g of red phosphorus was
calculated by dividing the total weight of phosphoric acid and
phosphorous acid with the weight of red phosphorus contained in the
molded articles.
[0084] Raw Material
[0085] The red phosphorus powder and the red phosphorus master
pellets used in the examples are as follows.
[0086] (1) Coated red phosphorus powder
[0087] As the coated red phosphorus powder, NOVAEXCEL 140 made by
Rinkagaku Kogyo Co., Ltd. was used. The details of the coated red
phosphorus were as follows.
[0088] The coated red phosphorus powder having coatings of the
following {circle over (1)} and {circle over (2)}, is composed of
essentially spherical red phosphorus directly obtained by a
conversion treatment method of yellow phosphorus, not requiring
pulverization and without having crushed surfaces, and has a mean
particle diameter of 30 .mu.m:
[0089] {circle over (1)} A coating with a cured phenolic resin
obtained by suspending the essentially spherical red phosphorus in
water, adding phenol and formalin therein and heating;
[0090] {circle over (2)} A coating composed of aluminum hydroxide,
positioned under the above-mentioned coating and making a contact
with the red phosphorus;
[0091] (2) Red phosphorus master pellet
[0092] The red phosphorus mater pellets were prepared as follows.
That is, the aromatic polycarbonate having a viscosity-averaged
molecular weight as described in Table 1 and 2, with the
above-mentioned coated red phosphorus powder were compounded in
prescribed amounts as described in the Tables, and melted and
kneaded by a single- or twin-screw extruder.
Examples 1 to 5 and Comparative Examples 1 to 9
[0093] The compositions of examples 1 to 5 are shown in Table 1 and
the compositions of comparative examples 1 to 9 are shown in Table
2. The units in the composition in the Tables are expressed in part
weight.
[0094] In all cases, a twin-screw extruder of TEX 44 (made by Nihon
Seiko Co., Ltd. and having each screw diameter of 44 mm) was used,
as the extruder. The barrel temperature was at 250.degree. C in the
examples 1 to 4 and in the comparative examples 1 to 8, and at
280.degree. C. in the example 5 and in the comparative example 9.
The output rate was in all cases at 50 Kg/hr. The compositions
described in Tables 1 and 2, were melted and kneaded at a screw
rotation rate of 150 r.p.m., and then pelletized by using
pelletizer. The extrusion processing of the examples were
stable.
[0095] The obtained pellets were dried at 130.degree. C. for 5
hours, and burning test pieces and flat plate test pieces were
molded at 260.degree. C. of cylinder temperature and 60.degree. C.
of mold temperature in the examples 1 to 4 and in the comparative
examples 1 to 8, and also at 280.degree. C. of cylinder temperature
and 60.degree. C. of mold temperature in the example 5 and in the
comparative example 9.
[0096] By using these pellets and test pieces, burning tests, the
amounts of phosphine generation, the amounts of phosphoric acid
generation were evaluated. The results are shown in Tables 3, 4 and
5.
1TABLE 1 Composition Example Example Example Example Example (part
weight) 1 2 3 4 5 PBT 100 100 100 100 PET 40 40 PBN 100 Glass fiber
110 110 100 100 80 Red phosphorus master 65 65 85 85 45 pellet 1
Titanium oxide 1 1 1 Aluminum oxide 1 1
[0097] where, each of the components in Table 1 is as follows.
[0098] PBT: Polytetramethylene terephthalate, made by Teijin
Limited; intrinsic viscosity, 0.88.
[0099] PET: Polyethylene terephthalate, made by Teijin Limited;
intrinsic viscosity, 0.83.
[0100] PBN: Polytetramethylene naphthalene dicarboxylate, made by
Teijin Limited; intrinsic viscosity, 0.76
[0101] Glass fiber: made by Asahi glass Co., Ltd., T124.
[0102] Red phosphorus master pellet 1: A master pellet composed of
the coated red phosphorus powder (made by Rinkagaku Kogyo Co.,
Ltd., NOVAEXCEL 1 140) of 15 weight %, and the aromatic
polycarbonate (made by Teijin Chemical Co., Ltd.; Panlite L1225;
viscosity-averaged molecular weight, 22,200) of 85 weight %.
[0103] Titanium oxide: made by Ishihara Sangyo Kaisha, Ltd.;
CR-80.
[0104] Aluminum oxide: Kanto Chemical Co., Ltd.; specially pure
grade.
2TABLE 2 Com. Com. Com. Com. Com. Com. Com. Com. Com. Composition
Expl. Expl. Expl Expl Expl. Expl. Expl. Expl. Expl. (part weight) 1
2 3 4. 5 6 7 8 9 PBT 100 100 100 100 100 100 100 100 PET 40 40 PBN
100 Glass fiber 110 110 100 100 100 100 100 100 100 Red phosphorus
85 85 85 85 85 85 master pellet 1 Red phosphorus 65 master pellet 2
Red phosphorus 65 master pellet 3 Red phosphorus 13 master pellet 4
PC 72 Titanium oxide 0.01 Aluminum oxide 0.01 Zinc Oxide 0.5 Cupric
oxide 0.5 ('Com. Expl.' means 'Comparative Example')
[0105] where, each of the components in Table 2 is as follows.
[0106] PBT: Polytetramethylene terephthalate, made by Teijin
Limited; intrinsic viscosity, 0.88.
[0107] PET: Polyethylene terephthalate, made by Teijin Limited;
intrinsic viscosity, 0.83.
[0108] PBN: Polytetramethylene naphthalene dicarboxylate, made by
Teijin Limited; intrinsic viscosity, 0.76.
[0109] PC: An aromatic polycarbonate, made by Teijin Chemical Co.,
Ltd.; Panlite L1225; viscosity-averaged molecular weight,
22,200.
[0110] Glass fiber: made by Asahi glass Co., Ltd.; T124.
[0111] Red phosphorus master pellet 1: A master pellet composed of
the coated red phosphorus powder (made by Rinkagaku Kogyo Co.,
Ltd.; NOVAEXCEL 140) of 15 weight %, with the aromatic
polycarbonate (made by Teijin Chemical Co., Ltd.; Panlite; L1225;
viscosity-averaged molecular weight 22,200) of 85 weight %.
[0112] Red phosphorus master pellet 2: A master pellet composed of
a crushed red phosphorus, which is on the market, of 15 weight %,
with the aromatic polycarbonate (made by Teijin Chemical Co., Ltd.;
Panlite L1225; viscosity-averaged molecular weight, 22,200) of 85
weight %.
[0113] Red phosphorus master pellet 3: A master pellet composed of
the coated red phosphorus powder (made by Rinkagaku Kogyo Co.,
Ltd.; NOVAEXCEL 140) of 15 weight %, with the aromatic
polycarbonate (made by Teijin Chemical Co., Ltd.; Panlite; L1225L;
viscosity-averaged molecular weight, 19,700) of 85 weight %.
[0114] Red phosphorus master pellet 4: A master pellet composed of
the coated red phosphorus powder (made by Rinkagaku Kogyo Co.,
Ltd.; NOVAEXCEL 140) of 30 weight %, with the polytetramethylene
terephthalate [made by Teijin Limited; intrinsic viscosity, 0.87
(dl/g)] of 70 weight % (provided that the amount of the
tetramethylene terephthalate in this master pellet is included in
100 parts weight in PBT column, therefore the amount shown in the
red phosphorus master pellet column is the amount of only the
coated red phosphorus powder).
[0115] Titanium oxide: made by Ishihara Sangyo Kaisha; CR-80.
[0116] Aluminum oxide: Kanto Chemical Co., Ltd.; specially pure
grade.
[0117] Zinc oxide: made by Kanto Chemical Co., Ltd.; specially pure
grade.
[0118] Cupric oxide: made by Kanto Chemical Co., Ltd.; first
grade.
3TABLE 3 Character- Example Example Example Example Example istics
1 2 3 4 5 0.8 mm V - 0 V - 0 V - 0 V - 0 V - 0 UL94 burning
property Generated 3.2 .times. 10.sup.-5 2.7 .times. 10.sup.-5 3.1
.times. 10.sup.-5 2.8 .times. 10.sup.-5 3.3 .times. 10.sup.-5
amount of phosphine (g/g) Generated 0.8 .times. 10.sup.-4 0.9
.times. 10.sup.-4 0.9 .times. 10.sup.-4 0.9 .times. 10.sup.-4 0.9
.times. 10.sup.-4 amount of phosphoric acid (g/g)
[0119]
4TABLE 4 Comparative Comparative Comparative Comparative
Characteristics Example 1 Example 2 Example 3 Example 4 0.8 mm UL94
V-0 V-2 V-0 HB burning property Generated 2.2 .times. 10.sup.-2 --
9.5 .times. 10.sup.-5 -- amount of phosphine (g/g) Generated -- --
0.9 .times. 10.sup.-4 -- amount of phosphoric acid (g/g)
[0120]
5TABLE 5 Character- Comp. Comp. Comp. Comp. Comp. istics Example 5
Example 6 Example 7 Example 8 Example 9 0.8 mm V - 0 V - 0 V - 0 V
- 0 V - 0 UL94 burning property Generated 9.0 .times. 10.sup.-5 8.5
.times. 10.sup.-5 9.7 .times. 10.sup.-5 1.0 .times. 10.sup.-5 9.8
.times. 10.sup.-5 amount of phosphine (g/g) Generated 0.8 .times.
10.sup.-4 0.9 .times. 10.sup.-4 1.6 .times. 10.sup.-4 9.4 .times.
10.sup.-2 0.9 .times. 10.sup.-4 amount of phosphoric acid (g/g)
[0121] As clearly shown by Tables 3, 4 and 5, by forming a master
pellet with the coated red phosphorus powder having a cured resin
coating and consisting of the essentially spherical red phosphorus
directly obtained from a conversion treatment of yellow phosphorus,
not requiring the pulverization and without having crushed
surfaces, and the aromatic polycarbonate resin in advance, a highly
flame retardant property is obtained. Further, by using titanium
oxide and aluminum oxide , it becomes possible to reduce the
generation of phosphine, while inhibiting the generation of
phosphoric acid.
[0122] Effect of Invention
[0123] The flame retardant resin composition in the present
invention is a non-halogenated flame retardant resin composition
and can provide a resin composition having a high degree of flame
retardant property, equipped with good electric characteristics by
inhibitong the generation of phosphoric acid, and improved in
working environment and safety. The resin composition in the
present invention can be used suitably as electric/electronic parts
and automobile parts on being molded as a molded article.
* * * * *