Note: Descriptions are shown in the official language in which they were submitted.
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Thermoplastic resin composition
The present invention relates to thermoplastic resin
compositions, More particularly, it relates to thermo-
plastic resin compositions comprising polycarbonate
resins and having good physical properties such as impact
resistance and heat resistance wi~h improved weld strengthO
Polycarbonate resins have excellent physical
properties, in particular high impact resistance and heat
resistance, and are known as 'lengineering plas~icsl'. It
is also known that various other re~ins can be blended
with polycarbonate resins for enhancing the physical
properties of the polycarbonate resins and or improving
their deterioration resistance. Fox instance, incorpora-
tion of ABS resins (acrylonitrile-butadiene-styrene
copolymer), MBS resins (methyl methacrylate~butadiene-
s~yrene copolymer) or ABSM resins (acrylonitrile-butadiene-
styrene-methyl methacrylate copolymer) into polycarbonate
resins is effective for improving their moldabillty and
reducing the thickness dependency of impact resistance
(Japanese Patent Publns. (examined) Nos. 15225/1963,
71/64, 11496/67 and 11142/76). Further, for instance,
incorporation of AES resins (acrylonitrile-ethylene/
propylene rubber-styrene copolymer3 into polycarbonate
resins i~ effective for improving their weather re~istance
and stain resistance (Japanese Patent Publn. (unexamined)
No. 48547/1973J.
In injection molding, which is the most popular mold-
ing procedure, the number of gates and the flow state of
t~e resin must be changed according to the form and size
of the desired product. For this reason, resin flowing
in different directions usually unavoidably comes into
contact, thus forming weld parts. The weld part of a
molded product made of a conventional thermoplastic resin
composition comprising a polycarbonate resin containing
a rubber modified copolymer is usually insufficient in
strength, and this is a great drawback for practical use
of the resulting products.
As a result o~ extensive study, it has now been found
that the incorporation of an epoxy group-containing olefin
copolymer into a thermoplastic resin composition compris-
ing a polycarbonate resin and a rubber modified copolymer
affords a resinous composition having good physical proper-
ties such as impact resistance and heat resistance with
improved weld strength.
According to this invention, there is provided a
thermoplastic resin compo6ition which comprises (A) a
polycarbonate resinr (B) a rubber modified copolymer,
and (C) an epoxy group-containing olefin copolymer.
Examples of the polycarbonate resin used as component
(A) are aliphatic polycarbonates, aromatic polycarbonates,
aliphatic-aromatic polycarbonates, etc. Usually, polymers
and copolymers of bisphenols, e.g. bis(4-hydroxyphenyl)
alkanes/ bis(4-hydroxyphenyl)ethers, bis(4-hydroxyphenyl)
sulfones, bis(4-hydroxyphenyl)sulfides and bis(4-hydro~y-
phenyl)sul~oxides, and~or halogenated bisphenols are
employed. T~pical examples of the polycarbonate resins
and their production are described in various textbooks
and literature references including the Encyclopedia of
Polymer Science and Technology, Vol. 10, pages 710 to 764
(1969).
The rubber modified copolymer used as component (B)
can be obtained by pol~merizing at least two kinds of
monomers chosen from aromatic vinyl compounds, vinyl
cyanides and alkyl esters of unsaturated carboxylic a~ids
in the presence of rubbers. The resulting product com-
prises (b-l) a copolymer comprising units of the rubber
and units of the monomers graf~ polymerized thereon
(hereinafter referred to as the "graft copolymer") usually
with (b-2) a copolymer comprising unit~ of the monomers
(hereinafter referred to as the "copolymer"). Alterna-
tively, the graft copolymer (b-l) and the copolymer (b-2)
may be separately produced and combined together to form
a uniform composition which can be used as component (B).
In general) the rubber modified copolymer (B~ comprises
the graft copolymer ~b-l) and the copolymer (b-2) respec-
tively in amounts of lO to 100 % by weight and of 90 to
0 % by weight on the basis of the total weight of the
rubber modified copolymer ~Bj. When the content of the
graft copolymer (b-l) is le~s than 10 ~ by weight, the
ultimate coposition has insufficient impact resistance.
The weight proportion o the rubber and the monom~rs
in the graft copolymer (b-l) is normally from 5 ~ 95 ko 70
: 30. the composition of the monomers is not limited and
may comprise, for instance~ an aromatic vinyl compound(s)
in a content of 50 to 80 ~ by weight and a vinyl cyanide(s)
and/or an alkyl ester of unsaturated carboxylic acid(s) in
a content of 50 to 20 % by weight. NQ particular restric-
tion is present on the particle size of the graft copolymer
(b-l), but it is usually from 0O05 to S microns, preferably
from 0.1 to 0.5 microns.
The composition o the monomers in the copolymer (b-2)
is also not limited and may comprise, Eor example, an arom-
atic vinyl compound(s) in a content of 50 to 90 % by weight
and a vinyl cyanide(s) and/or an alkyl ester of unsatur-
ated carboxylic acid ~5) in a content of 50 to lO ~ by
weight. No special limitation is present on the in~rinsic
viscosity of the copolymer (b-2), and it is usually from
0.60 to 1.50 (when determined in dimethylformamide at
30C).
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Examples of the rubber for the grat copolymer (b-l)
are polybutadiene, styrene/butadiene copolymer, acrylo~
nitrile/butadiene copolymer, ethylene/propylene copolymer,
ethylene/propylene/non-conjugated diene copolymer (e.g.
dicyclopentadiene, ethylidenenorbornene, 1,4-cyclohexa-
diene, l,4-cycloheptadiene, 1,5-cyclooctadiene~, ethylene/
vinyl acetate copolymer, chlorinated polyethylene, poly-
alkyl acrylate~ etc. When the ethylene/propylene copoly-
mer of the ethylene/propylene/non-conjugated diene
copolymer are employed/ the molar ratio of ethylene and
propylene may be from 5 : 1 to 1 O 3~ The non-conjugated
diene content in the ethylene/propylene/non-conjugated
diene copolymer is preferably from 2 to 50 in terms of the
iodine value. Examples of the aromatic vinyl compound(s)
are styrene, ~-methylstyrene, methyl-~-methylstyrene,
vinyltoluene, monochlorostyrene, etc~ Examples of the
vinyl cyanide(s) are acrylonitrile, methacrylonitrile,
etc. Examples of the alkyl ester of unsaturated car-
boxylic acid(s) are alkyl acrylates (e.g. methyl acrylate,
ethyl acrylatel butyl acrylate)y alkyl methacrylates ~e.g~
methyl methacrylate, ethyl methacrylate, butyl methacryl-
ate), hydroxyalkyl ~crylates (e~g~ hydroxyethyl acrylate,
hydroxypropyl acrylate), hydroxyalkyl methacrylate (e.~.
hydroxyethyl methacrylate, hydroxypropyl methacrylate),
etc.
Any conventional polymerization procedure may be
adopted for the preparation of the rubber modified
copolymer (B) such as emulsion polymerization, suspension
polymerization, bulk polymerization, solution polymer-
ization, emulsion-su~pension polymerization and bulk~
suspension polymerization.
In the thermoplastic composition of the invention, the
wei~ht proportion of the polycarbonate re~in (A) and the
rubber modified copolymer ~B) may be from 10 : 90 to 90 :
10. When the content of the polycarbonate resin (A) i5
smaller than the lower limit, the heat resistance and
the weld strength are much reduced. When the content is
larger than the upper limit, the moldability is remarkably
reduced. In addition, the appearance deteriorates to the
extent that the product is not suitable for practical use.
The epoxy group-containing oleEin copolymer (C) is a
copolymer of at least one unsaturated epoxy compound and
at least one olefin with or without at least one ethylen-
ically unsaturated compound. While no special limitation
is present on the relative proportions o these monomers,
the content of the unsaturated epoxy compound(s) is
preferably from 0O05 to 95 ~ by weight.
Examples of the unsaturated epoxy compound(s) are
those having an unsaturated group copolymerizable wi~h an
olefin and an ethylenically unsaturated compound as well
as an epoxy group in the molecule. For example, unsat-
urated gly~idyl esters, unsaturated glycidyl ethers,
epoxyalkenes, p-glycidylstyrénes, etc. are suitable.
Those of the following formulas are also suitable:
O
R-C-O-CH2-CH-CH2 (I)
o
R-X-CH CE~-CH (II)
~ ~ ~ 2
o
R'
R-C-CH (III)
~of 2
wherein R i5 a C2-C18 hydrocarbon group having an
ethylenic unsaturation, ~' is a hydrogen atom or a methyl
group and X is -CH2O-, ~ O- or - ~ . More
specifically, the following compounds are examplified.
glycidyl acryl~te, glycidyl methacrylate, glycidyl
itaconate, butenecarboxylates, allyl glycidyl ether,
2-methylallyl glycidyl ether, styrene-p-glycidyl ether,
3S 3,4-epoxybutene, 3r4-epoxy-3-methyl-l~butene, 3,4-epoxy-
l~penteneO 3,4-epoxy-3-methylpentene r 5,6 epoxy-l-hexene,
vinylcyclohexene monoxide, p-glycidylstyrene~ etc.
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Examples of the olefin(s) a~e ethylene, propylene,
butene 1, 4-methylpentene-1, etc.
Examples of the ethylenically unsaturated compound(s),
are olefins, vinyl esters having a C2~C6 saturated
carboxylic acid moiety, acrylic and methacrylic esters
having a Cl-C8 saturated alcohol moiety, maleic esters
having a Cl C8 saturated alcohol moiety, vinyl halides~
vinyl ethers~ N-vinyllactams, carbonamides, etc. These
ethyleneically unsaturated compounds may be copolymeriæed
with the unsaturated epoxy compounds and the olefins in an
amount of not more than 50 % by weight, especially from
0.1 to 45 ~ by weight, based on the total weight of the
monomers to be copolymerized.
The epoxy group-containing olefin copolymer ~C) may
be prepared by various procedures, of which one typical
example comprises contacting an unsaturated epoxy compound
and an olefin with or without an ethylenically unsaturated
compound with a radical generating agent at a temperature
of 40 to 300C under a pressure of 50 to 4000 atm. Another
typical example comprises irradiating a mixture of poly
propylene and an unsaturated epoxy compound with gamma
rays under a high vacuum.
No particular restriction is present on the amount
of the epoxy group-containing olefin copolymer ~C~ to be
incorporated in the mixture, and the amount is usually
rom 0.1 to 40 parts by weight to 100 parts by weight of
the total weight of the polycarbonate resin ~A) and the
rubber modified copolymer (B). When the amount is less
than the stated lower limit, a satisfactory dispersibili~y
is not assured. When more than the upper limit, layer
separation is apt to ~e produced in the molded product.
To produce desirable impact strength/ weld strength and
processability of the thermoplastic resin composition, an
amount of from 0~5 to 10 parts by weight is particularly
preferable.
For the preparation of the thermoplastic resin compos-
ition of the invention, the said essential components may
be mixed together in any optional order. For exarnple, all
of ~hem may be mixed together at the same time. Further,
~or example, two of them may be first mixed together,
followed by introduc~ion of the remaining one into the
resultant mixture Mixing may be achieved by the use of
any conventional mixing apparatus eOg. a banbury mixer,
a monoaxial extruder or a biaxial extru~erO If desired,
another resin, e.g. a polyolefin resin (e.g. polyethylene~
polypropylenel ethylene/propylene copolymer) and/or
additive(s) e.g. dyestuffsr pigmentsl stabilizers, plas-
ticizers, antistatic agents, ultraviolet ray absorbers,
flame retardant agents, lubricants and fillers, may be
incorporated into ~he thermoplastic resin composition.
Practical and presently preferred embodiments ~f
the invention are illustratively shown in the following
Examples wherein ~ and part(s) are by ~eight unless
otherwise indicated.
Examples 1 to 10 and Comparativ2 Examples 1 to 7
According to the formulation as shown in Table 1 or 2,
the polycarbonate resin (A), the rubber modified copolymer
(B) and the epoxy group-containing olefin copolymer (C) or
polyethylene were mixed together to form a thermoplastic
resin composition, of which the physical properties are
also shown in Table 1 or 2.
The polycarbonate resin (A~ and the polyethylene resin
employed were the commercially available materials. The
rubber modified copolymer (B) and the epoxy group-contain-
ing olefin copolymer (C) were prepared as set forth here-
inbelow.
Polycarb~nate resin (A):-
"Panlit L-1250W" manufactured by Teijin Chemical.
Rubber modified copolymer (8) (No~
Graft copolymer (b-l)
Polybutadiene (~el content, ~0 %) (~0 parts (in ~erms
of solid)~/ potassium persulfate (0.5 part), potassium
olefinate (0.5 part) and dodecylmercaptan ~0.5 part) were
~ ~3~~
mixed together, styrene (36 parts) and acrylonitrile (14
parts) were added thereto, and polymerization was carried
out at 70C for 3 hours~ followed by aging for 1 hour.
The reaction mixture was subjected to salting out, dehydra-
tion and drying to give a graft copolymer of 0.3 to 0.4
micron in particule size.
Copolymer (b-2)
To a mixture of styrene (70 parts) and acrylonitrile
(30 parts), t-dodecylmercaptane 50.1 part) was added, and
the resultant mixture was subjected to pre-polymerization
in a bulk state at 90C for 3 hours. Water (210 parts),
methylcellulose (1.0 part) and benæoyl peroxide (0.3 part)
were added theretoD The resulting aqueous dispersion was
heated from 30C to 90C, and polymerization in a disper-
sion state was carried out for 10 hours. Removal of the
water gave a copolymer having an intrinsic viscosity of
0.50 (when determined in dimethylformamide at 30C).
Rubber modified copolymer ~B) (No~ 2):-
Graft copolymer (b-l~
Ethylene/propylene/non-conjugated diene copolymer
(EPDM) (iodine value, 8~5; Mooney viscosity, 61, propylene
content, 43 % by weight; non-conjugated diene component,
ethylidenenorbornene) (150 parts) was dissolved in a
mixture of n-hexane (3000 parts) and dichloroethylene
(1500 parts). Styrene (300 parts3, acrylonitrile (150
parts) and benzoyl peroxide ~11 parts) were added thereto,
and polymerization was carried out at 65C for 10 hours in
nitrogen atmosphere. The reaction mixture was con~ac~ed
with a greatly excessive amount o~ methanol. The precipit
3Q ate was collected by filtration and dried to give a graft
copolymer (rubber content, about 24 %).
Copolymer (b-2)
To a mixture of styrene (70 parts) and acrylonitrile
(30 parts), t-dodecylmercaptane (0.1 part) was addedy and
the resultant mixture was subjected to pre-polymerization
in a bulk state at 90C for 3 hours. Water (210 parts),
methylcellulose ~1~0 part) and benzoyl peroxide (0.3 part)
were added thereto. The resulting aqueous dispersion was
heated from 30C to 90C, and polymerization in a disper-
sion state was carried out for 10 hours. Removal of the
water gave a copolymer having an intrinsic viscosi~y o~
0.50 (when determined in dimethylformamide at 30C).
Epoxy group-containing olefin copolymer (C):-
Into an autoclave, compressed ethylene (2000 kg/cm~),glycidyl methacrylate and vinyl acetat~ were charged
together with di-t-butyl peroxide as a catalyst, and the
mixture was stirred at 150 to 300C for several minutes
while stirring, whereby bulk-polymerization proceeded.
The reaction mixture was passed through a separator to
collect an epoxy group-containing olefin copolymerO
Polyethylene res~n:~
"Sumika~hen Har ~ 2703" manufactured by Sumitomo
Chemical.
The weld strength was determined as follows:
A melted resin (200C) was injected from two gates
(each being 2.5 x 2.0 mm) having a gate distance of 100
mm to make a test piece 15G mm long, 150 mm wide and 3 mm
high. The test piece was placed on a cylinder of 120 mm
in inner diameter, 126 mm in outer diameter and 80 mm in
height. A steel ball of 1 kg was dropped onto the central
part of the test piece in a room kept at -30~C, and the
maximum energy (kg~cm) that could be absorhed without the
test piece breaking was measured.
Table 1
Example Comparative Example
Test No. ~ ~
1 2 3 4 5 1 2 3
Polycar~onate resin ~Aj 40 50 50 60 70 50 60 50
(part(s))
Rubber modified copolymer
(B) (No. 1) (part(s)J
Graft copolymer (b-l) 25 30 15 20 lG 30 20 30
Copolymer (b-2~ 35 20 35 20 20 20 20 20
Epoxy group-containin~
olefin copolymer (C) (part(s))
E-GMA-VA*l) 3 - 3 - 2 - - -
E-GMA*2~ - 2 - 1.5 - - - -
Polyethylene ~part(s)j ~ 3
Weld strength (DuPcnt~200~20G 190~ 200 180 20 25 45
impact strength at weld
llne) ~-3QCC) (kg.cm)
Notched Izod impact 48~656.6 4~.5 52.0 51.0 55.0 56O3 53.2
s~rength (20C3 (k~.cm/cm2~
Heat distortion tempera-100.5 105.0106.0108.711203105.2 106.5 105.8
ture (264 psi~ no annealing)
( C)
Processability (Koka-type0~51 0.50 0~55 0.480.420.50 0.56 0.58
flow tester, ~30Cs 60
kg~cm~) (ml/m7 n)
F~exural modulus~ x 104 2.0 2.1 2.2 2~15 20 5 2~1 2.2 2.05
( kg/cm2 )
Note: *1~ Ethylene/glycidyl methacrylate/vinyl acetatQ copolymer (90 : 7 : 3)O
*2~ Ethylene/glycidyl methacrylate copolymer (90 : 10).
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