Note: Descriptions are shown in the official language in which they were submitted.
3~3~
HI~H NITRILE RESINS CONTAINING MALEIC ANHYDRIDE
This invention relates to novel. polymeric
compositions which have high heat-distortion temperatures,
good gas barrier properties and low creep characteristics
which are composed of an olefinically unsaturated nitrile,
another monovinyl component and maleic anydride and
optionally a conjugated diene monomer, and to the process
for manufacture of these compositions.
The novel polymeric products of this invention are
prepared by polymerizing a major portion of an olefinically
unsaturated nitrile, such as acrylonitrile, and a minor
portion of another monovinyl monomer component which mus.t
include maleic anhydride optionally in the presence of a
preforme~ rubbery polymer composed of a conjugated diene
monomer, such as butadïene.
The conjugated dienes useful in this invention
include butadiene-1,3, isoprene, chloroprene, bromoprene,
cy-anoprene, 2,3-dimethyl butadiene, and the like. Most
preferred for the purpose of this inven-tion are butadiene
and isoprene be.cause of their ready availability and their
excellent copolymerization properties.
The olefinically unsaturated nitriles useful in
this invention are ~he alpha,~eta-olefinically unsaturated
~ononitriles having the structure CH2=C-CN wherein R is
. R
hydrogen, a lower alkyl group having from 1 to 4 carbon
atoms, or a halogen. Such compounds include acrylonitrile,
alpha-chloroacrylonitxile, alpha-~luoroacrylonitrile,
methacrylonitrile, e~hacrylonitrile, and the like. The most
preferred olefinically unsaturated nitrile is acrylonitrile.
.~ ~ 1 - ~ .
The other monovinyl monomer component copoly-
merizable with the olefinically unsaturated nitriles which
are useful in this invention includes one or more of the
vinyl aromatic monomers, esters of olefinically unsaturated
carboxylic acids, vinyl esters, vinyl ethers, alpha-olefins,
~ and others.
- The v;nyl aromatïc monomers include st~rene,
alpha-methyl styrene, the vinyl toluenes, the vinyl xylenes,
and the like. Most preferred are styrene and alpha-methyl
styrene.
The es-ters of olefin;cally unsaturated carboxylic
acids include those having the structure CH2=C-COOR2
wherein Rl is hydrogen, an alkyl group having from 1 to 4
carbon a~oms, or a ~alogen, and R2 ïs an alkyl group having
from 1 to 6 car~on atoms. Compounds of this type include
methyl acrylate, ethyl acrylate, the propyl acrylates, the
butyl acrylates, the amyl acrylates, and the hexyl acrylates;
methyl methacrylate, ethyl methacrylate, the propyl methacrylates,
the butyl methacrylates, t~e c~myl methacrylates, and the hexyl
methacrylates; methyl alpha-chloroacrylate, ethyl alpha-
chloroacrylate~ and the like. Most preferred in the present
invention are methyl acrylate, ethyl acrylate, methyl
metha-crylate, and ethyl methacrylate.
The alpha-olefins useful in the present invention
are those havin~ at least 4 and as many as 10 carbon atoms
and having the ~tructure ~' wherein R' and R" are alkyl
C~23C
.. , I
;~ R
groups having from 1 -~o 7 carbon atoms, and more specifically
- 2 -
~,rp~;~3~ .
preferred are alpha-olefins such as isobutylene, 2-methyl
butene-1,2-methyl pentene-l, 2~methyl hexene-l, 2-methyl
heptene-l, 2-methy-l octene-l, 2-ethyl butene-l, 2-propyl
pentene-l, and the like. Most preferred is isobutylene.
The vinyl ethers include methyl vinyl ether, ethyl
vinyl eth.er, the propyl vinyl ethers, the bu-tyl vinyl ethers,
methyl i.sopropenyl ether, et~yl isopropenyl ether, and the
like. Most preferred are methyl vinyl ether, ethyl vinyl
ether, the propyl vinyl ethers, and the butyl vinyl ethers.
The vinyl esters include vinyl acetate, vinyl
propi.onate, the vinyl ~utyrates, and the like. Most preferred
is vinyl acetate.
Maleic anhydride is an essential component o the
novel compositions embodied in this invention.
The polymeric compositions of the present
invention can he prepared by any of the known general
techniques of polymerïzation, including the bulk :
polymerization, solution polymerization, and emulsion or
suspensi.on polymerization techniques by batch, continuous or
intermittent addition o the monomers and other components.
Th.e preferred method i.s ~y solution polymerization in the
presence o a suita~le solvent and a ree-radical generatirlg
polymerization ini.tiator at a temperature in the range of
from ahout Q to 100C in the su~stantial absence of molecular
oxygen.
The rub~ery polymers which may be included in the
resins of this ïnvent;on are homopolymers of the conjugated
di.ene monomers mentioned a~ove as well as copolymers o these
dienes and another monomer component such as acrylonitrile,
~tyrene, ethyl acrylate, and mix~ures thereof, wherein
:~ .
.
i3~ :
there is present at least 50% ~y weight of the total -
monomers of the conjugated dïene monomer.
: The preferred polymeric compositions embodied
herein are those resulting Erom the polymerization of
lao parts by weight of ~A~ at least 50% ~y weight of at least
one nitrile having the structure C~I2=C-CN wherein R has
R
the foregoing designation, CBl from 1 to 30~ by weight of
malei.c anhydride, and ~Cl from 5 to 25% by weight based on
the com~ined weigh.t of ~A~ plus (B~ plus (C~ of at least one
member selected from the group con~isting of (1) styrene or
alpha-methyl styrene, (;2) an ester having the structure ~ .
CH2=C-COOR2 wherein Rl and R2 have the forego.ing ;~
R
designations, (3~ an alpha-ole~in having the structure R'
CH2= lC
R" ~:
,
~h.erein R' and R" have the foregoing designations, (4~ a ~.
vinyl ether selected from the group consisting of methyl
2a vinyl ether, ethyl vinyl ether, the propyl vinyl ethers, and
the butyl vinyl ethers, and (51 vinyl acetate, in the presence
o~ from a to 40 parts by weight of (Dl a rubbery polymer of
a conjugated diene monomer selected from the group consisting .
of butadiene and isoprene and optionally at least one
comonomer selected from the group consisting of styrene, a :~
nitrile monomer having the structure CH2=CI-CN wherein R
has the foregoing designation, and an ester having the
structure CH2-C-COOR2 wherein Rl and R2 have the foregoing
. 30 Rl
. ~ .
.~ .
,. . . ~ `' ' '. '' ', ' ' '. , `, :
.
;3~i ~
designations, said rubbery polymer containing from 50 to 100%
by weight of polymerized conjugated dïene and from 0 to 50%
by weigh.t of comonomer~ Prefera~ly, component (A) should be
present in from a~out 60 to ~0% ~y weight, component (B)
should be present in from 1 to 30~ ~y we:igh-t and component (C)
should he present ln from 5 to 25% by we:ight based on the
combined weight of (A~ plus (~ plus (C).
- The novel polymers produced ~y the process of this
invention are readi.ly processed th.ermoplastic materia:Ls
which can ~e thermoformed into a wide vari.ety of useful
articles in any of the conventional ways employed with
known thermoplast;c materials, such as by extrusion, milling,
molding, drawing, injecting, etc. The polymeric products of
this inventi.on have excellent solvent resistance and their
impact strength and low permea~ility to gases and vapors
~ake them useful in the packaging ïndustry, and they are
particularly useful in the manufacture of bottles, ilm,
sheet, pipes and other types of containers for liquids and
solids.
~;: 20 In the following illustrative examples, the amounts
of ingredients are expressed in parts by weight unless
otherwise indicated.
Example 1
A. An acrylonitrïle-styrene copolymer which is
outside the scope of the present inven-tion was prepared in a
polymerization reactor to ~hich were added 75 parts of ..
acrylonitrile, 3 parts of styrene and 75 parts of methyl
.~ ethyl ketone. The mixture was stirred and ~rought to 76C
under an atmosphere of nitrogen. A feed of 22 parts of
styrene~ 25 parts of methyl ethyl ketone and 0.3 part of
: 5
~f~
. .,
'
;3~;
azohisisobutyronitrile was added continuously and uniformly
over a 4.5-hour period. The final reaction mixture was
maintained at 76-78C for an additional hour. The overall
conversïon of monomers to polymer was 68% of theory.
The contents of the reactor were poured into a
stïrred mixture of 1:1 ~y volume benzene:petroleum ether.
; The solid polymer was isolated and dried at reduced pressure
and 45-60C for 48 hours. This resin was found to have an
ASTM heat-distortion temperature of 84-94C, a flexural
strength of 17.1 x 103 psi, a flexural modulus of 5.50 x 105 psi,
a tensîle strength of 14.1 x 10 psi, an oxygen transmission
rate of 3.5 cc-mil/100 inches ~24 hours/atmosphere and a
water vapor transmission rate of 8.0 gm-mil/100 inches2/24
hours/atmosphere.
B. An acrylonitrile-styrene-maleic anhydride
terpolymer which ïs within the scope of the present invention
was prepared by the procedure of A of this ~xample except
that the continuous feed was made up of 5 parts of maleic
anhyaride, 17 parts of styrene, 25 parts of methyl ethyl
ketone and 0.3 part of azo~isisobutyronitrile and the
continuous feed was added uniformly over a 5 hour period. ~ `
The overall conversion of monomers to polymer was 30% of
theory. The resin thus produced was found to have an ASTM ~ ;
heat-distortion temperature of 102C, a flexural strength of
18.7 x 103 psi, a flexural modulus of 6.06 x 105 psi, a
~ 3
tensile strength of 15~2 x 10 psi, an oxygen transmission
.~ ~ .
, rate of 4.6 cc-mil/100 m ches /24 hours/atmosphere and a
,.
water vapor transmission rate of 0.9 gm-mil/100 inches /24
hours/atmosphere.
Example 2
The procedure of Example lA was followed except
-- 6 --
~, ,
~ .
65~
that the initial reactor charge was 70 parts of acrylonitrile,
2.8 parts of styrene, 75 parts of methyl ethyl ketone and
t~e continuous feed was made up of 5 parts of maleic
anhydride, 22.2 parts of styrene, 25 parts of methyl ethyl
ketone and 0.3 part of azo~isisobutyronitrile. The continuous
~eed was added unïformly over a 6-hour period. The overall
conversion of monomers to polymer was 81% of theory. The
resulting resinous polymer was found to have an ASTM heat-
distortion tempera-ture of 104C, a flexural strength of
18.g x 103 psi, a flexural modulus of 6.13 x 105 psi and a
tensile strength of 14.2 x 103 psi.
Example 3
A polymer was prepared ~y the procedure described
in Example 2 using an initial reactor charge of 70 parts of
acrylonitrlle, 2.8 parts of styrene and 75 parts of methyl
ethyl ketone and a continuous feed made up of 10 parts of
maleic anhydride, 17.8 parts of styrene, 25 parts of methyl
~`~ ethy-l ketone and 0.3 part of azo~isiso~utyronitrile. The
; resulting resin was found to h~ve an ASTM heat-distortion
2Q temperature of 107C, a flexural modulus of 6.03 x 105 psi
an oxygen transmission rate of 2.7 cc-mil/100 inches2/24
hours/atmosphere and a water vapor transmission rate of
- 5.4 gm-mil/lOa inches2~24 hours/atmosphere.
~` xample 4
; A. ~ copolymer of acrylonitr;le and methyl
acrylate which i5 outside the scope of this invention was
prepared ~y adding to a polymerization reactor 75 parts of
acrylonitrile, 25 parts of methyl acrylate, 100 parts of
methyl ethyl ketone and a. 1 part of azobisisobutyronitrile.
The polymerization reaction was carried out for 2 hours at
_ 7 -
.
77C with stirring under a n;trogen atmosphere. The polymer
~as isolated by coagulation wïth a 1:1 by volume mixture of
henzene:petroleum ether. The dried resinous polymer was
found to have an ASTM heat-distortïon temperature of 76C,
a flexural strength of 21.4 x 103 psi, a flexural modulus of
6.56 x 105 psi, a -tensile strength of 10.6 x 103 psl, an
oxygen transmission rate of 0.35 cc-mil/100 inches2/24
hours/atmosphere and a water vapor transmïssion rate of
4.3 gm-mil/lQ0 inches2/24 hours/atmosphere.
B. The procedure of A of this Example was ;~
~ollowed except that the ingredients of the polymerization -
mixture were 7a parts of acrylonitrile, 20 parts of methyl
acrylate, 10 parts of maleic anhydride, lOa parts of methyl
ethyl ketone and 0.1 part of azo~;sisobutyronitrile. The
resulting polymer was found to have an ASTM heat-distortion
te~perature of 83C, a flexural strength of 25.5 x 10 psi,
a flexural modulus of a. 75 x 10 psi, a tensile strength of
13.4 x 103 psi, an oxygen transmission rate of 0.24 cc-mil/100
inches2/24 hours/atmosphere and a water vapor transmission
; 20 rate of 3.2 gm-m;1/100 inches2/24 hours/atmosphere.
Example 5
The procedure of Example 4A was repeated except
that the ingredients of the polymerization mixture were
60 parts of acrylonitr;le, 20 parts of methyl acrylate,
2Q parts of maleic anhy-dride, 100 parts of methyl ethyl
ketone and 0.1 part of azo~isiso~utyronitrile. The
resulting polymer ~as found to have an ASTM heat-distortion
tempera-ture of 7~C, a flexural strength of 21.7 x 103 psl,
a flexural modulus of 6.49 x 105 psi an~a tensile streng~h
of 16.2 x 103 psi.
- - 8 -
. ~ ' .
