Note: Descriptions are shown in the official language in which they were submitted.
75~
This invention relates to cFoss-linlcable interpolymers comprising
a major proportion of one or more oleElns and one or more esters of acrylic
acid and a minor proportion of a vinyl aromatic compound having a halo-
methyl group substituted for one of the aromatic ring hydrogens.
More particularly, this invention relates to interpolymers, having
elastomeric properties when cross-linked by means of nucleophilic reagents,
said interpolymers prepared with the aid of a catalyst system comprising a
Lewis acid and a free-radical generator from monomers comprising one or
more acrylic or alicyclic olefins; one or moreacycllcor alicyclic esters
of acrylic acid wherein the acyclic or alicyclic radical moiety is free of
olefinic unsaturation or readily replaceable halogen; and from 0.3 to 30
mol percent of the total monomers present in said interpolymer of a halo-
methylated aromatic vinyl compound.
Most particularly, this invention relates to interpolymers, having
elastomeric properties when cross-linked by means of one or more nucleo-
philic reagents, prepared with the aid of a catalyst system comprising a
Le~is acid and a free-radical generator such as an organic peroxide com-
prising (A) about 50 mol percent of one or more Cl to C20 acylic or alicyclic
esters of acrylic acid in which the Cl to C20 acyclic or alicyclic ester
~ 20 radical moiety is free of olefinic unsaturation or readily replaceable hal-
: ogen; and a total of about 50 mol percent of the sum of: (B) one or more
C2 to C20 acyclic or alicyclic Type I (R-CH=CH2) or Type III (R(R')C=CH2)
mono-olefins wherein R and R' are independently selected from the group
consisting of hydrogen, and Cl to C18 straight and branched chain alkyl
radicals, aryl, alkylaryl, arylalkyl and cy ~ alkyl radicals; and (C) 0.3
to 30 mol percent, preferably not more than 10 mol percent (in the
: , . . . , , ~ ~
,,;............. ~ ,: ~ , . :, :
. .
.
.
: : .
10~i~75~
total interpolymer) of one or more halomethylated aromatic vinyl compounds.
While the preferred method for the preparation of the interpolymers
of this invention is from the said monomers, an alternative method comprises
polymerizing ~A) one or more Cl to C20 acyclic or alicyclic esters of
acrylic acid in which the Cl to C20 ester radical moiety is free of olefinic
unsaturation or readily replaceable halogen; (B) one or more C2 to C20
acyclic or alicyclic Type I or Type III monoolefins; 0.3 to 30 mol percent
of an aromatic vinyl compound, followed by halomethylation of the aromatic
ring in the interpolymer.
The interpolymers of this invention may be blended, prior to
cross-linking, with halogenated polymers such as halogenated polyolefins;
halogenated butyl rubber; halogenated terpolymers such as the brominated
EPDM described in U.S. Patent 3,524,826 issued October 18, 1970 to Esso
Research and Engineering; sulfochlorinated polyolefin elastomers such as ~ ~;
Hypalon*; polychloroprenes such as neoprene; polyvinyl chloride; epichloro~
hydrin rubbers. Such blends may also include process oils, plasticizers, ~-
resins, fillers and reinforcing agents. The cross-linked elastomers of this
invention possess a high tensile strength, elongation and modulus and are ; ~ -
useful as general or special purpose elastomers.
The highly reactive nature of the halogen in a halomethyl group
attached to an aromatic ring not only facilitates cross-linking at moderate
vulcanization temperatures but provides a means for conversion of the
halomethyl moiety to a variety of derivatives having increased utility.
...
For example, reaction of the interpolymers of this invention with reagents
well known to those having ordinary skill in the chemical arts permits -
conversion of the halomethyl group
. .; .
':' , '
*Trade Mark -
- - 3 -
. ~
i(J~;~75~
to a cyanomethyl group; hydroxymethyl group; carboxymethyl group; aldehyde
group; thiomethyl group; aminomethyl group; alkoxy methyl group; methylene
ester of a carboxylic acid; quaternary nitrogen halides and the like. These
may be further reacted with for example difunctional reagents to give cross-
linked networks. Non-limiting examples include reaction of the hydroxymethyl
and aminomethyl derivatives with a dibasic acid or anhydride, or reaction
of the carboxylic acid derivative with a glycol.
Copolymers of alkyl acrylates with chlorine containing monomers
are old in the art. For example, copolymers of ethyl acrylate with from
2.5 to 5 percent of 2-chloroethyl acrylate or 2-chloroethyl vinyl ether have
been available commercially as Lactoprene* EV since 1944.
Similar copolymers including alkyl acrylates or substituted alkyl
acrylates are disclosed in U.S. Patents Wos. 3,201,373 issued August 17,
1975 to American Cyanamid; 3,578,636 issued May 11, 1971 to Sumitomo;
3,629,215 issued December 21, 1971 to Sumitomo; and 3,63S,924 issued
January 18, 1972 to Sumitomo, and Belgian Patent No. 763,733 published
September 3, 1971 to Sumitomo.
In distinction to the products and processes of the prior art, it
has now been found that interpolymers which have elastomeric properties
when cross-linked by means of nucleophilic reagents may be prepared from
monc~mers which comprise tA) one or more Cl to C20 acyclic or alicyclic
esters of acrylic acid wherein the es*er radical moiety is free of olefinic
unsaturation or halogen which will react with nucleophilic reagents under
the conditions normally used for the vulcanization of elastomeric compositions -
referred herein as "readily replaceable halogen"; (B) one or more C2 to C20
acyclic or alicyclic Type I or Type III monoolefins; and (C) one or more
halomethylated aromatic vinyl compounds by means of a catalyst system
comprising a Lewis acid and a free-radical generator.
*Trade Mark
_ 4 _
~ .
,. : ~' ' ''
, . ~ .
t~5~ .,
The interpolymer contains about 50 mol percent o~ the acrylic
ester and a totaL o~ about 50 mol percent of the oleEin and chloromethylated
aromatic ~finyl compound Witll the llmitat:ion that the halomethylated aromatic
vinyl compouncl does not exceed more than 30 mol percent, preferably not
more than 10 mol percent, of the monomers present in the interpolymers.
The properties of the interpolymer suggest a micro-structure
for the polymer chain in which acrylate ester monomer units a]ternate with
either an olefin monomer unit or a randomly distributed halomethylated
aromatic vinyl monomer unit. According to this structure a segment of the
interpolymers of this invention may be illustrated as follows:
~ --(B-A) ~^~ C)~ (A~B)n----------
wherein m and n are integers which cannot be determined with any major degree
of accuracy with the analytical methods available at the present time, but
for any particular macromolecule of the instant invention~may be in the
range of 1 to about 500. ,~
For the specific case where the acrylate ester (A) is ethyl
acrylate; the olefin (B) is isobutylene; and the halomethylated aromatic
vinyl compound (C) is 4-chloromethyl styrene, a segment of the interpolymer
macromolecule of this invention may be iilustrated as follows: -
20 /~ R H H~ H H ~H H H R~
, . . . . . . . - ~ ~
C-C-C-C ' C-C : C-C C-C
.... 1. ........... ,, I
\~R H c=a/ H C6H4CH2Cl\~ ,C O H R,~
OR' - OR'
where R is a methyl radical, R' is an ethyl radical and m and n are as
indicated above.
~ 5 ~ ;~
:
" ~
., .
':.,. '', ' ~ ' ' .' ' - ; ' ' ,' , ' ' ~ . ~
lL~ 5
. onomers
crylic_L~.~ters
Cl to C20 acyclic or alicylic esters oE acrylic acid in which the
ester radical moiety is free of olefinic unsaturation or readily replaceable
halogen may be illustrated by the general for~ula CH2=CH-COOR wherein R is
selected from the group consisting of straight or branched chain primary
alkyl radicals, arylalkyl radicals, cycloalkylalkylene radicals, and per-
fluoroalkyl radicals. Non-limiting examples are: methyl; ethyl; n-propyl;
n-butyl; isobutyl; n-amyl; n-hexyl; 2-ethyl-hexyli n-octyl; isooctyl, derived
by the oxonation of mixed heptenes followed by hydrogenation; isodecyl;
3,5,5-trimethylhexyl; n-dodecyl; tridecyl; tetradecyl; heptadecyl; octa-
decyl; benzyl; hexahydrobenzyl; and perfluoro butyl radicals.
B. Olefins
Mon-olefins suitable for the practice of this invention include
C2 to C20 hydrocarbons which may be Type I olefins having the general
formula R-CH=CH2 and Type III olefins having the general formula R'(R')C=CH2
~herein R and R' are independently selected from the group consisting of
hydrogen; straight and branched-chain alkyl radicals; aryl; alkylaryl;
arylalkyl and cycloalkyl radicals having from 1 to 18 carbon atoms. ~`
Non-limiting examples of suitable Type I olefins include: ethylene, ,
propylene; l-butene; l-pentene; l-hexene; 4-methyl-1-pentene; 1 heptene;
4,4-dimethyl-1-pentene; l-octene; l-nonene; l-decene; 3,7-dimethyl-1-octene;
l-dodecene; l-tridecene; l-tetradecene; l-octadecene; styrene; 4-methyl-
styrene; vinyl cyclopentane; vinyl cyclohexane; 2-vinyl norbornane;C~-vinyl
naphthalene; 5,5,7,7-tetramethyl-1-octene; and 3,6,10-trimethyl-1-hendecene.
-- 6
... .
.. , ~ , . . . . . . .
: :.:.-, . .. ~ . . , :
:,: . -, :: . . .
:, :. -, ', :
: . :
Non-limitillg examples o~ suitn~le Type III olefins include:
isobutylene; 2,3-dimethyl-l-butene; 2,4,4-trimethyl-1-pentene; 2,6-dimethyl-
l-octene; 4-isopropellyl toluene; isopropenyl cyclopentarle; ~-methyl styrene,
l-isopropenyl naphthalene; 2,5,9-trimethy:l-1-decene; 2,6,10-~rimethyl-1-
hendecene; and 2,7,11-tr:imethyl-1-dodecene.
The general formulae used to illustrate the types of olefins
suitable for the practice of this invention are based on the Boord Class-
ification described by Schmidt and Boord in ~.A.C.S. 54, 751 ~1932).
C. Halomethyl Aromatic Vinyl Compounds
Cg to Cl8 halomethyl aromatic vinyl compounds useful in the
practice of this invention may be illustrated by the general formula
CH23CH-R-CH2X wherein R is an arylene radical having from 1 to 3 rings
and X is a halogen independently selected from the group consisting of
chlorine, bromine and iodine. Non-limiting examples include: 3-chloro-
methyl styrene; 4-chloromethyl styrene; 1-vinyl-4-chloromethyl naphthalene;
4-chloromethyl-2,3,5,6-tetramethyl styrene; 4-bromomethyl styrene; 3-
chloromethyl-4-methyl styrene; 3-methoxy-4-chloromethyl styrene. Of
particular utility lS a commercially available chloromethylated styrene
herein referred to as VBC (vinyl benzyl chloride) which is a mixture of
approximately 60 wt. percent of the meta isomer and 40 wt. percent of the
para isomer.
II Catalysts
Catalyst compositions suitable for the practice of this invention ~-
comprise, in combination, a Lewis acid and a source of free-radicals. Pre-
ferred Lewis acids are metal halides and alkyl aluminum halides and pre-
ferred sources of free-radicals are organic peroxy compounds and azo com-
pounds. In addition to the Lewis acid reagent and peroxy compound,
~ ,
-:: : -: : . : , , : :.
, . ~ . , ., . . , ~, , , :
. ~ . : : -: , - . : . . . ~ : : . , -. :. . . ::
~:,::.. , .: . ,-: : . , - .. , ,, " ~ , ; :
;: :. , : . - , , .,~ , . . .
::: .: , i . . : ~ : . .
i;3 75~
co-catalysts p~rticularly vanadi~lm compouncls may optionally be used to
enhance and direct the activity o~ the catalyst system. In no case should
thP Le~is acid be pre-reacted with the halomethyl aromatic vinyl compound
since doing so inter~eres with the proper lncorporation of the monomer in
the interpolymer chain.
Non-limiting examples of Lewis acids which are suitable for the
practice of this invention include: Aluminum trichloride, aluminum tribromide,
aluminum triiodide, hydrofluoric acid, boron trichloride, boron tri1uoride,
ferric chloride, stannic chloride, zinc chloride, zirconium tetrachloride,
and organoaluminum halides having the general formula AlR X wherein R is a
monovalent hydrocarbon radical selected from the group consisting of Cl to
C12 alkyl, aryl, alkylaryl, arylalkyl and cycloalkyl radicals, m is a number
from 1 to 3, X is a halogen selected from chlorine, bromine and iodine, and
the sum of m and n is 3. Preferred are ethyl aluminum sesquichloride,
Etl 5AlC11 5 and ethyl aluminum dichloride, EtAlC12.
Useful co-catalyst vanadium compounds have the general formula
VO Xt wherein z has a value of O or 1, t has a value of two to four, and
X is independently selected from the group consisting of chlorine, bromine,
iodine, acetylacetonates, haloacetylacetonates, alkoxides and haloalkoxides.
Non-limiting examples include VC14, VOC13, VO(OEt)3, VOC12(0Bu), V(AcAc)3,
VO~AcAc)2, and VOC12(AcAc) where ~AcAc) is an acetylacetonate.
While free-radical generators such as ultraviolet light and
high-energy radiation may be used as the source of free-radicals in the
catalyst system of this invention, preferred are organic peroxides, hydro-
peroxides, peracids, peroxyesters and azo compounds. Non-limiting examples
- 8 -
- . -- , :: . : : : :: :
` ' ' - , ' , ` . " ' ' ' : , ' ' . .
- - ~
75(~
include benzoyl peroxide: acetyl peroxkle, Lauroyl peroxide; t-butyl
peroxide; t-butyl peracetate; t-butyl peroxypivalate; cumene hydroperoxide;
2-methyl pentanoyl peroxide, dic~lmy:Lperoxide and 2,2'-azo b:is(lsobutyroni-
trile).
r~e concentration of the individual catalyst components may be
varied over a wide range depending on the reactivity of the individual
monomers. Suitable mol ratios of acrylate ester to organoaluminum halide,
for example, may range from l to 2000 mols of acrylate ester per mol of
organoaluminum halide, or higher. Preferred is a ratio of 5 to 1500 mols
of acrylate ester per mol of organoaluminum halide. Most preferred is
a rat~io of from about 10 to 1000 mols of acrylate ester per mol of organo-
aluminum halide. ,
The peroxide component is similarly variable over a wide range ofmol ratios. Suitable ra~ios range from 10 to 2000 mols of acrylate ester
per mol of peroxide or azo compound. Preferred is a ratio of from about -
20 to 1000. Most preferred is a ratio of from 30 to about 500 mols of
acrylate ester per mol of the free radical generator. `-~
As indicated above, a vanadium co-catalyst may optionally be
used to enhance the activity and selectivity of the prlncipal catalyst
system. When used, the vanadium compound may be added to the catalyst
system in the range of from 1 to about 100 mols of organoaluminum halide per
mol of vanadium compound. Preferred is a range of from 2 to 50. Most
preferred is a molar ratio of from about 3 to 30 mols or organoaluminum
halide per mol of vanadium compound.
- III Solvents
Suitable media for dissolving or dispersing the monomers, catalyst
components and polymeric reaction products include the general group of ali-
- phatic and aromatlc petroleum hydrocarbons and halogenated hydrocarbons.
.. 9 _
~,~
.,.~
:: : ., . , : . . , - . . -:, :. ,, : :: :- . ,
.:: - .. : - -: ~: . .:. .:. : . :: : . . :
~s~
~cyclic or alicyclic C~ or lower ~traigh~ or brallcl~ed chaLtl saturated hydro-
carbons ~nd sromatic hydrocarbolls are preferred. Cl to C8 halogenated hydro-
carbons are also userul solvents. Choice oE a particular solvent or mlxture
of solvents will depend on the process conditlons, e.g. whether a homo-
geneous solution process, suspension or slurry process, or cement suspension
process is used.
In a homogeneous solution process for the production of high-
molecular weight polymers, the concentration of polymer in the cement is
usually limited to the range of 5 to 10 weight percent, since higher con-
centration require excessive power input to insure good mixing, efficientheat-exchange is difficult to achieve and the high viscosity of the solution
at the temperatures which are usually employed during the polymerization
reaction causes sticking and fouling of the reactor with the reaction
products.
In a slurry process in which the monomers and catalyst components
are soluble in the solvent, but in which the po~ymer is not, higher con-
centrations of dispersed polymer in the range of 10 to 20 wt. percent may
be attained. Similar concentrations may be handled in reactors e~uipped
with conventional mixers in a cement-suspension process in which a single
or mixture of solvents is chosen which yields two phases; a dispersed cement
phase of polymer swollen with monomers and solvent and a continuous phase
consisting essentially of the pure solvent containing a small amount of
monomers. Any of the above solvent systems may be used in batch, semi-
continuous or fully continuous processes.
Non-limiting examples of suitable solvents which may be used alone
or in admixture include: butane; pentane; cyclopentane; hexane; heptane;
isooctane; benzene; cyclohexane; toluene; methyl cyclohexane; mixed xylenes;
-- 1~) --
::: , ~ :: - .,
::: : -: . ,.................. . . ::: .
' ~,:: : .,: :
c~lmene; methyL chlorlde; methylene chlori(le; dlchloroethane; orthodlcloro-
bellzene ancl fluorinated or chloroÇluor:Lnatecl C2 to C4 acyclic hydrocarbons.
Solvents which are known to form stnble complexes or coordination compounds
~ith any of the catalyst components, particularly the Lewis acid, or vanadium
compound iE used as a co-catalyst, are undesirable and should be avoided.
IV Process Conditlons
The interpolymers oE this invention may be prepared in batch,
semi-continuous or fully continuous processes in which homogeneous solution,
slurry or cement-suspension solvent systems are utilized. In a typical
batch process, a reactor fitted with efficient agitation means, and means
for cooling the reaction mixture and withdrawing the heat of reaction
is purged of air by displacement with oxygen-free nitrogen, argon or low-
boiling olefin-free hydrocarbon vapors such as methane, ethane or propane ;
and charged with dry solvent or mixture or solvents.
Monomers and catalyst components in all processes, pre-diluted
with solvent if desired may than be introduced into the stirred reactor,
either simultaneously or sequentially, at a rate consistent with the means
- used for heat-exchange to maintain the desired temperature range. Pressure
on the reactor is maintained at a leveI sufficient to keep the reactants
in the liquid phase. The catalyst components may be mixed in line in the
absence of monomers before they are added to the reactor, or they may be
added directly to the reactor in the presence of the monomers.
Temperatures at which polymerization may be conducted may range
from -100C to 100C. Preferred are temperatures ln the range of -80C
to 50C. Most preferred are temperatures in the range of -40C. to 40C.
-- 11 --
., ,
.. ~ . .. .... .. ~ - . .. , - .. , ..... . .. -
-~: - - . :: . . :: : , . . .
: ~ ~ - . . .. , : :
:i: :: : . .: . ~ : :. : , .
75(~
rhc tem~craturc m.~y ~c varied d-lrLn~l the tLme required for optlmum yleld
and polyner properties, wLth Eor example a low temperature durlng the
i~itial phase of the reaction and a higher temperature during the flnal
phase.
Reaction time may vary widely, depending on the reactivity of
the particular monomers, catalyst concentrat:Lon and temperature of the
reaction. Generally, reaction times are shorter at higher monomer, organo-
aluminum and peroxide concentrations and at higher polymeriæation temper-
atures. Accordingly, polymerization times may vary from as little as two
minutes to Z00 hours. Preferred are reaction times in the range of from
10 minutes to 24 hours. Most preferred are reaction times in the range
of 15 minutes to 10 hours.
Isolation of the interpolymer at the completion of the reaction
may be accomplished in a variety of ways. In a preferred embodiment, the
homogeneous polymer cement solution, or polymer suspension, or polymer
- cement suspensions is fed from the reactor in the case of a batch pro-
cess, or final reactor or holdi~ng drum in the case of a semi-continuous
or fully continuous process to a mixing drum where the reaction mixture has
been mixed either in line or is mixed in the drum with a quantity of a lower
alcohol such as methanol, ethanol or isopropanol in order to inactivate : -:
_ the catalyst mixture. The alcohol may optionally contain a sequestering
reagent such as ethylene diamine tetra-acetic acid or its disodium salt or
acetylacetone. While inactivation of the catalyst in the manner indicated
is preferred it is not essential and may be omitted if desired.
The polymer solution or suspension, with or without catalyst
inactivation is fed to an agitated wash drum where it is mixed with water
or a dilute aqueous solution of an acid such as hydrochloric or sulfuric
- 1:;~ -
~.
.
acid in order to deash the polymer. Acid treatment ~ollowed by thorough
water washing under efficlent agitation is repeated if necessary so as to
obtain a polymer with a minimal ash cont:ent.
Final isolation of the polymer in crumb form is accomplished by
feeding the polymer solution suspension to a slurry flash drum where it is
treated with steam and hot water to prec:ipitate the polymer and vaporize
the solvent. Typically, antioxidants, stabilizers and slurry aids are
added to the polymer solution or suspension before slurrying and removal
oE solvent. The water slurry of polymer is finally fed to dewatering and --
drying extruders before packaging in bale or crumb form. Solvents and un~
reacted monomers, vaporized in ~he slurry flash drums are purified and
recycled ~o the polymerization reactors.
V Cross-Linking Reagents
Generally, the same nucleophilic reagents which are used for
cross-linking and vulcanizing halogenated hydrocarbon elastomers, such
as chlorinated butyl rubber, in which the halogen is an allylic relation-
ship to a double bond may be used for cross-linking the interpolymers of
this invention. Preferred are nucleophilic compounds containing nitrogen
or sulfur or both, a comprehensive list of which may be found in "Materials
and Compounding Ingredients For Rubber and Plastics", published annually
by Rubber World, New York, N. Y.
Non-limiting examples include: diamines, diamine carbamates,
ethylene imine derived polyamines; alkylated thioureas particularly the
N,N'-dialkylthioureas, 2-mercaptoimidazoline, catechol salts, for examplè,
dicatechol borates and polymethylolphenol resins and their halogenated
derivatives.
The following examples illustrate the invention.
.
j - 13 -
::, : ~ ' : . . :
75~
E~ IPLE 1 - Pr~paratlon o~ an interpolyn~er of ethyl acrylate
_ _ _
l~obutylene iInd Chloromethyl Styrene
__ _ _ __ _
The polymerization was carried out in a pressure vessel fabri-
cated frorn a solid cylinder oE polypropylene which had been bored to create
a cylindrical cavity o~ 800 ml. ~le vessel was sealed.
The polymeri~ation vessel, contained in a dry-box from which air
and moisture were excluded by means of a positlve internal pressure of
oxygen-free and moisture-free nitrogen, was charged with 200 ml. of toluene
which had been purified by percolation through a column oE Linde* 3A mole-
cular sieves, 50 grams (0.5 mol) of a commercial grade of ethyl acrylatecontaining 15 ppm of 4-methoxyphenol as an antioxidant and 15.3 (0.1 mol~
grams of a commercial grade of chloromethyl styrene having an isomer
distribution of about 60 percent of the meta isomer and about 40 percent
of the para isomer, hereinafter designated VBC (commercially designated
as vinyl ben~yl chloride).
The pressure vessel was then immersed in a Freon 11 (trichloro-
fluoromethane) bath maintained at -20C., located in the dry box and
the vessel and contents cooled to -15C. There was then added to the
vessel in succession 7.5 ml. of a 1~0 molar solution of ethyl aluminum
~0 sesquichloride (Etl 5~1C11 5) in purified n-heptane, 56 grams (1.0 mol)
of liquefied isobutylene and 1 millimol of lauroyl peroxide dissolved
in 20 ml. of purified toluene. The reaction vessel was seal-ed, removed
from the freon bath and allowed to come to room temperature which required
- about 1 hour.
The rcaction vessel was then placed in a tumbling water bath
maintained at 32C. and tumbled for a period of 40 hours. The pressure
vessel contents were then transferred to a flask and the reaction terminated
by tlle addition of 15 ml. of isopropyl alcohol and 10 ml. of methanol.
. .
trade mark
- 1
.: . . : : : .
7~
~-- The elastomeric product was isolated by addition oE the solution
to a boiling water bath whereby the product precipitated as a slurry. The
product was filtered from the water and dried in a vacuum oven for 4 hours
at 60C. at a pressure of 20 torr. The yield of polymer was 20.4 grams.
It had an inherent viscosity of 0.52 in benzene solution at 0.1 g/dl at
25C.
A sample of the polymeric product dissolved in CC14 was examined
by NMR at 60 MHz. The structure of the interpolymer was determined by
using the chemical shifts at 7.0 ppm as a measure of aromatic protons, the
chemical shift at 4.5 ppm for the -CH2Cl group and the -OCH2-signal at 3.95
ppm for the ester. From the above the structure of the interpolymer was
determined as containing the following monomer residues: 52 mol percent
of ethyl acrylate; 23 mol percent of isobutylene and 25 mol percent of
chloromethyl styrene. The polymer was analyzed for C, H and Cl. Calculated
0-23; tAcry'0.52; VBCo 25; C=67.2, H=8.1~ Cl=8.6 Found:
C,66.6;H, 7.7; Cl, 9Ø
In the following two examples, experiments were carried out
- to determine whether prereacting the alkylaluminum halide with the chloro-
methyl aromatic vinyl compound was desirable.
EXAMPLE 2
The preparation and isolation of the interpolymer was the same
as was used in Example 1 except that 5.05 grams (0.033 moles) of VBC was
used instead of 0.1 mol. The isolated product had an inherent viscosity
in benezene at 25C. and a concentration of 0.1 g/dl of 0.76 and on analysis
by NMR showed monomer residues of 50 mol percent of ethyl acrylate; 41
mol percent of isobutylene, and 9.0 mol percent of ~BC. Calculated for:
.~ , , .
- 15 -
.,' , .,'.
7~
Isob~l ; Et~cry ; V~C ; C-68.5; Il=9.S, Cl=3.7. Eound: C, 68.1;
~l, 9.~; Cl, 4.2,
_.Xf PLL 3
The preparation and isolatlon of the interpolymer was in general
the same as Example 2 except that the VBC, dissolved in 100 ~l. of toluene
was prereacted at -20C. with the ethylaluminum sesquichloride and then
added to the ethylacrylate in toluene. The yield of polymer was 4.:l grams
and on elemental analysis contained only 0.16 weight percent of chlorine
and when examined by N~ did not show the chemical shift associated with
the -CH2Cl group. This result in comparison with that of Example 2 shows
that prereacting the alkylaluminum halide with the chloromethyl aromatic
compound is to be avoided.
E.YAMPLES 4 to 7
A series of runs were made in the same manner as Example 1,
in which the molar proportions of VBC and catalyst were varied. The
quantities used and the results obtained are given in Table I.
TABLE I
INTERPOLYMERS OF ETHYL ACRYLATE, ISOBUTYLENE AND VBC( )
Example No. 4 5 6 7
VBC, mmols. 18 18 33 7
Etl 5AlGll 5 mmols 15 15 15
Reaction time, Hrs. ( ) 89 89 89 89
Polymer yield, gms. 74 79 77 77
Inherent Viscosity( ) 0.73 0.90 0.800.86
Notes: (a) All runs were made with 200 ml of toluene,
0.5 mol of ethyl acrylate, 1.0 mol of iso-
butylene and 1 mmol of lauroyl peroxide.
(b) All runs made at 32C.
(c) In benzene at a concentration of O.l g/dl
:
- 16 -
.'' . . ' ' -"' ~ . ' ' . ' . i ' :' ' ' ~ ': ' ' '
''. '' ' . ' . '`';"' '' '` ~ ' .`'" ' ' . ~ ' ' '' ' ''`' ' ' ' , , ' '
.. ~,':, : ' ' .'., ' : ,.. , : .
Sample 6 was examlnecl by NMR ancl analyzed for C, l~ and Cl.
N~IR an.llysis sllo~ecl monomer residues in the produ~t of 49 mol percent of
ethyL acrylate; ~7 mol percent oE isobutylene; and 4 mol percent of the
chloromethyl styrene. Calculated for: IsobuO 47; EtAcryO 49; VBCo 04;
C=69.1; ll=9.9; Cl=1.7. Found: C, 68.9; Il, 9.9; Cl, 1.9.
Samples 4, 5 and 7 had on analysis a chlorine content of 1.0,
1.3 and 1.0 weight percent, respectively.
EX~PLE 8
The interpolymer of Example 6 was compared with respect to rate
10 of cure, with a sample of an interpolymer of ethyl acrylate, isobutylene
and 2-chloroethyl vinyl ether prepared according to the teachings of the
Belgian Patent 763,333 referred to above. Both samples had essentially
the same chlorine content and were formulated on a rubber mill with the
same recipe. The recipe used was: interpolymer 100, zinc oxide 5, N,N'
dibutylthiourea 4. Samples were cured at 320F. for 30 minutes at a pres-
sure of 1200 psi and tested on the Instron machine at a strain rate of
20 inches per minute.
The product of Example 6 showed a tensile strength of 2665 psi,
an elongation at break of 225% and a modulus at 100% axtension of 950.
; 20 The product made with 2-chloroethyl vinyl ether showed a tensile of only
570 psi and an elongation of 700%.
While the preferred embodiments of this invention are elastomers,
it is possible by a suitable selection of components and their ratios to
produce thermoplastic and thermoset compositions. Also possible is the
production of lower molecular weight materials useful as oil additives.
- 17 -
-'. . . ~, ,-
: ' ' ~ : ' ' ' ` . ' - ' ' :
,:: ~ ' :' ' .- , ,:
' ` . : ' .
